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Detailed Paper about PostDates

Outline

1. DEFINITION: Postmaturity vs. Postdate
1. POSTDATES:
2. POSTMATURITY:
2. INCIDENCE OF
3. METHODS OF CALCULATING DUE DATES
4. CONTRIBUTING FACTORS
1. Delayed Ovulation:
2. Previous Obstetrical History and Family History:
3. Abnormalities
4. Mother's Emotions:
5. CHARACTERISTICS OF POSTDATE PREGNANCIES
6. IMPLICATIONS OF POSTMATURITY AND POSSIBLE PROBLEMS ASSOCIATED WITH POSTMATURITY
1. Fetal :
2. Placental Insufficiency :
3. Increased :
4. Emotional :
5. Mortality :
7. ANTENATAL CARE AND ASSESSMENTS
1. Routine Assessment:
2. Extra Assessment
8. THE GREAT DEBATE: To Induce or Not to Induce
9. PLAN OF ACTION
1. Conservative (no induction) Course:
2. Active Management - induction
10. VARIOUS PRACTICES AND POLICIES AMONG HOMEBIRTH PRACTITIONERS
11. MANAGEMENT DURING LABOUR
12. CARE OF THE POSTMATURE BABY
1. Meconium Staining:
2. Hypoglycemia in the Newborn:
13. STATISTICS
14. SUMMARY

( see attached glossary for definition of medical terms; words included in glossary are emphasized where they first appear.)

1. DEFINITION: Postmaturity vs. Postdate
1. POSTDATES:Pregnancy that goes beyond 42 weeks gestation or 294 days. It is based on a 28 days menstrual cycle and occurs when pregnancy exceeds 42 weeks from the first day of the last menstrual period. This is also the given definition of "prolonged pregnancy" by the International Federation of Obstetrics and Gynecology (FIDO).
2. POSTMATURITY:Postmaturity, or Postmaturity Syndrome (PMS) can only be diagnosed after delivery and is defined as a postdates pregnancy accompanied with a combination of the following newborn assessments:
1. no lanugo ( fine body hair )
2. long nails
3. abundant hair on head
4. calcified fetal skull

Also:
5. hanging or wrinkled skin, with the appearance of weight loss
6. dehydrated
7. alert face
8. peeling skin
9. little to no vernix
10. oligohydramnios
11. meconium or bile staining of skin
12. long, thin growth retarded body with long thin limbs
Postmaturity is now recognized as a consequence of chronic placental insufficiency rather than as a late or sudden-onset phenomenon occurring after 40 weeks. This syndrome is not confined to postdates infants, but may occur from 40 weeks or even earlier. The characteristics are very similar to those documented as "growth retarded" and "dysmature" fetuses, which are often diagnosed by small size, small liquor volume during the 3rd trimester. Only 5% of post-term babies are born with PMS - being small, undernourished, and asphyxiated all as a result of the aging placenta. (Oxorn)^[1]. Varney^[2] warns that only about one-third of pregnancies labeled postdates are actually postdates pregnancies.
Problems arise in regards to the significance and incidence of "postdates" pregnancy as there are numerous terms: post-dates, post term, prolonged pregnancy, and postmaturity. Yet each term has its own special nuance with different overtones. However, PMS is specific and confusion continues when a clearly pathological syndrome is described by a word that is also used to make a simple statement about the chronological duration of pregnancy.
2. INCIDENCE OF


This has been variously quoted from 1.5% 5 to 18% for post-term pregnancy depending on what menstrual dating / ovulation dating / early ultrasound* / routines of intervention were used in pregnancy care and the type and size of populations studied. Approximately 3.5 % to 10% of all pregnancies go postdates (up to 12% according to Oxorn ) when based on the first day of the last menstrual period (LMP) of a 28-day cycle. Another study found that 12% of menstrually dated post-term babies were in fact postterm^[3]. Thus a longer than 28-day cycle will invalidate the gestational age calculation according to dates. 70% of these are due to incorrect dates or delayed ovulation. However, routine ultrasound examination* has reduced this to 6% ^[4][5][6]. Yet, elsewhere Bergsjø^[7] comments on various studies which have shown that reliability of ultrasound may not be as great as menstrual dating, being of greater value only in uncertain menstrual history (irregular menstrual cycles?). 25% of postdate pregnancies will develop into PMS. This occurs 15-20% more often in primips.^[8] Some women will have a history of postdatism. The PerinatalMortality Rate (PNMR) is lower than for women who have not previously gone overdue^[8]. One GP was quoted to say that pregnancies in the tropics, such as Northern Queensland, are longer and labours shorter.^[8]

In an article titled "Prolonged Pregnancy; The Management Debate", authors Cardozo, Fysh and Pearse write; "We conclude that with modern use of ultrasound to determine gestational age and detect Intrauterine growth retardation (IUGR), fewer mothers exceed 42 weeks gestation than previously reported and their fetuses are at less risk of antenatal or intrapartum asphyxia."^[9]

*NOTE: The discussion of ultrasound does not belong in this paper, and is only of use to you if you have already had earlier ultrasound dating and you are now facing prolonged pregnancy. Although ultrasound determination of gestational age is above mentioned as a possibly reliable method, the routine use of ultrasound is not recommended by the World Health Organization, the United States Food and Drug Administration ( FDA ) of the United States Department of Drug and Human Services.^[10]

3. METHODS OF CALCULATING DUE DATES


The accepted defined length of human gestation is 280 days from the first day of the Last Normal Menstrual Period (LNMP) in a 28 day cycle; OR given that ovulation occurs approximately 14 days prior to menstruation, then 266 from ovulation. Methods which arrive at the estimated due date (EDD) include:

1. Counting 40 calendar weeks from LNMP
2. Naegele's Rule - which takes LNMP and then adds 7 days plus 9 months. This varies by a day or two according to which months fall in this time (e.g. February)
3. 38 calendar weeks from known ovulation/conception date.
If these dates are unavailable, other methods of calculating the baby's due date include:
1. Ultrasound dating in the 1st or 2nd trimester of pregnancy. I again refer back to Bergsjø's ^[7] comments on various studies which have shown that reliability of ultrasound may not be as great as menstrual dating, being of greater value only in uncertain menstrual history (irregular cycles?); that fetal biparietal diameter is more accurate than measurement of fetal crown-rump length; and that measurements after the 24th week have no predictive value. He also notes that with such wide spread use of ultrasound now, operator error can be expected to increase and other important criteria for term assessment may be neglected.
2. Quickening, or the first fetal movement felt by the mother. This is usually about 18 weeks, and earlier if it is not the first baby, but not completely reliable.
3. From uterine size as palpated bimanually in the 1st trimester, or from later fundal heights. These too may vary by several weeks.
Ballantyne^[4] discussed the subject of dating at great length, including the following points:
1. The fertilization date may vary from ovulation and even insemination date, given that sperm can live up to approximately 10 days in a favourable environment.
2. Ballantyne cites 2 studies of cows, where "normal" gestation is 280 days as for humans, and where insemination dates can be observed with certainty. In those studies, length of gestation and a wide normal variability with normal outcomes, and the predisposition toward longer or shorter pregnancies was demonstrated in individuals. This variation is also very true for humans!
It is therefore apparent that in spite of (because of?) all our knowledge and modern technology, there are very wide and unknown variables determining when a baby is "started" and what is its own normal length of gestation. After all, one must keep in mind that as with individual people, individual children, individual infants and individual fetuses, we all grow and develop at different rates.

(N.B. An interesting note: Beicher et al. ^[11] quoted Gibson on the Irish practice of calculating the EDD from the last rather than the 1st day of LNMP "in order that a considerable number of patients escape the mental anxiety which so often accompanies the forty-first week of pregnancy"!)

4. CONTRIBUTING FACTORS
1. Delayed Ovulation:
1. breastfeeding
2. coming off of birth control pills
3. dieting
4. sustained physical effort such as marathon running
5. miscarriage of an immediately previous pregnancy
6. extreme stress or shock
These would account for the miscalculation of estimated due date rather than for going past dates.
2. Previous Obstetrical History and Family History:
1. Previous postdate pregnancies: with this history the mother has a 50% chance of repeating the pattern.
2. Vaginal bleeding / threatened miscarriage in the current pregnancy: this is thought to be an indication or cause of possible placental insufficiency later in the pregnancy.
3. Abnormalities
1. malpresentation leading to lack of cervical stimulation needed to initiate labour
2. umbilical cord problems
3. anencephaly
4. pituitary/adrenal insufficiency in fetus (often related to anencephaly)
5. placental suphatase deficiency : an x-linked recessive (chromosomal) disorder characterized by male fetuses / low estriols (a pregnancy hormone) / prolonged pregnancy
6. extrauterine pregnancy
(Points 3 - 6 are rare in occurrence, therefore do not warrant further discussion here.)
4. Mother's Emotions:
1. not willing to "let go":
1. last baby
2. waiting for someone significant to arrive or leave
3. parenting fears
4. home environment concerns
5. etc.
5. CHARACTERISTICS OF POSTDATE PREGNANCIES


Common characteristics are found in "postdate" pregnancies (and also in some pregnancies even at or before term) that are cause for concern. These characteristics call for closer monitoring and greater consideration of fetal well-being than might otherwise be the case in term pregnancies:

1. Oligohydramnios
2. Decreased fetal movement
3. Changes in fetal heart rate patterns: These are caused by variable cord compression, which is a result of lowered liquor volume and presents itself as follows:
1. non-reactive: the fetal heart does not increase with contractions, stimulation, or fetal movement;
2. decelerations: the fetal heart rate drops either directly after some seconds delay (late) in response to contractions, movements or stimulation
3. non-variability or "flat tracing": the fetal heart rate lacks the normal 5-15 beats per minute variation;
4. bradycardia / tachycardia : heart rate outside the normal range of 0-160^[12]
The most commonly seen abnormal heart rate patterns are a) and b)
4. Low estriol (a pregnancy hormone) levels
5. Meconium on amnioscopy (viewing the amnion and the liquor through the cervix without rupturing - see glossary )
6. IMPLICATIONS OF POSTMATURITY AND POSSIBLE PROBLEMS ASSOCIATED WITH POSTMATURITY
1. Fetal :
1. Ossification of fetal skull thus making moulding of baby's head during the birth difficult or impossible;
2. Macrosomia ( Big Baby ! - weighing over 4000 gms at birth ) :
1. CPD (cephalic-pelvic disproportion - see glossary)
2. shoulder dystocia
3. cephalhematoma
4. subdural haematoma
5. fractures and palsies ( nerve damage causing paralysis resulting from difficult assisted delivery )
3. Hypoglycemia ( low blood sugar ) particularly in babies characterized as macrosomic or postmature. (See Section XII: Care of the Postmature Baby)
4. Polycythaemia ( higher number of red blood cells ). No further comment was made of this, but babies in this state may be at greater risk of jaundice.
5. Hypothermia ( low body temperature ) in the postmature baby with low fat stores.
2. Placental Insufficiency :
1. oligohydramnios
1. increased incidence of cord compression
2. increased incidence of fetal distress
2. placental calcification
1. decrease in fetal bodily functions including kidney functions leading to oligohydramnios and associated problems.
2. decrease in fetal nourishment which leads to the baby metabolizing its own fat cells
3. fetal weight loss ( as a result of b. above )
4. oxygen deficiency particularly during contractions
NOTE: Dr. John Stevenson, a homebirth doctor from Victoria, writes " calcified placentas are not over due, they often feature in ultrasound reports in the 7th and 8th month. Calcification is just a normal variation of no significance. "^[12]
3. Increased :
1. IUFD: intra uterine fetal death
2. postpartum hemorrhage
3. cesarean sections: due to failed routine induction
4. hospital transfer:
1. fetal distress
2. meconium staining : occurs when the baby passes meconium into the amniotic liquor while in the uterus and is considered an "outstanding feature" as it tends to be thicker in PMS (which is consistent with a decreased liquor volume in which the meconium would otherwise be more diluted). This may accentuate the problems associated with meconium aspiration (inhalation) which may develop into a serious complication. Please refer to H.O.M.E. Manual, Vol. 1, "Meconium in Liquor" for more detailed information.
3. respiratory distress - difficulty in breathing, usually as a result of b. above.
4. Emotional :
1. mother's
2. effect on family
Several authors made brief mention of maternal anxiety as a problem of prolonged pregnancy. The great emphasis put on the EDD of 40 weeks as the " golden day " or " D day " as many mothers say, creates an atmosphere of anxiety, as well as social and medical pressure for the 50 % of women delivering after that date, and more so for the 10 % who will be pregnant at 42 weeks with conservative management.
5. Mortality :Again, from the literature reviewed, there are varying and sometimes contradictory statistics resulting from the many studies over the last 40 years and the different populations studied. Sims et al. ^[13]. show the conflicting statistics in the table below: She goes on to say that the infants at the greatest risk are those of less than 2500g birth weight, and that the most frequent causes of death associated with prolonged pregnancy are congenital malformations.


Bergsjø^[7] gives quite a different picture of perinatal mortality in the above table, quoting large scale statistics from Scandinavia 1979 - 81. Commenting on these tables he concludes that in this population, perinatal mortality is lower post term than at 37 - 39 weeks, with a drop between those times. The highest perinatal mortality is 6.7 per 1000 at 37 and 38 weeks, and 5.7 per 1000 over 40 weeks. Quoting Naeye ( 1978 ), Bergsjø goes on to give the major causes for post-term perinatal death as follows.

• 26% Severe congenital abnormalities
• 19% Amniotic fluid infection ( no other information given regarding circumstances ),
• 10% Abruptio placenta
• followed by other causes.
The incidences of congenital anomalies is higher in postdates than in term gestations^[6] and accounts for approximately 25% of the perinatal mortality of infants born postdates. However, this would account for the prolongation of pregnancy rather than the postmaturity accounting for the mortality.^[14]

Ahn and Phelan ( 1989 ), in quoting McClure Brown's study ( 1963 ) states that:^[15]

1. Perinatal mortality increases after 42 weeks, doubles at 43 weeks, and quintuples at 44 weeks gestation;
2. Further more, this higher rate of mortality is found in post term infants up to 2 years of age ( quoting Zwerdling, 1967 )
3. In quoting Sachs & Friedman ( 1986 ) they also state that " perinatal mortality rates were not significantly increased among postdate infants, but for small for gestational fetuses, the perinatal mortality rate was 6 to 7 times higher " .
This last statement reflects other authors comments that the fetuses showing growth retardation or " postmaturity syndrome " are at greater risks than fetuses who continue to be well nourished by the placenta.
7. ANTENATAL CARE AND ASSESSMENTS
By introducing routine intervention, we tend to dismiss our clinical
watchfulness . . . Our most common sin is that we do not pay attention
to clinical detail and I believe that more is to be gained here than
in routine application or expensive machines and biochemical assays.

- Bergsjø [7]

In addition to the usual antenatal care, the following assessments are sometimes included or may have greater significance in a post-dates pregnancy.
1. Routine Assessment:
1. Situations giving rise to concern regarding placental insufficiency:
1. malnutrition for more than one week due to poverty, vomiting, nausea, etc.
2. prolonged poor diet for any reason,
3. smoker : carbon monoxide, one of 4000 chemicals in cigarettes, reduces the oxygenating capacity of the blood by 12% resulting in oxygen starvation for the baby^[16]; nicotine acts as a vasoconstrictor causing reduction of blood flow through the placenta ^[17] thus leading to the decrease in oxygen and available nutrients to the baby^[18]. Varney writes that smoking as few as 2 cigarettes a day decreases fetal breathing movements in an otherwise normal pregnancy^[19].
4. APH ( bleeding prior to labour ) unrelated to the placenta. Indicative of poorly adhered placenta ( Vitamin E may be taken to strengthen the placental bed. ^[20] )
5. no Braxton-Hicks contractions after 34 weeks gestation: Possibly due to inadequate hormonal activity. A pregnancy tonic containing, blue cohosh, black cohosh, squawvine, birthroot, raspberry leaf started by 34 weeks will help balance this out. (CAUTION: Blue Cohosh, caulophyllum thalictroides, may lower blood pressure.) These can all contribute to PMS, or put a post-term pregnancy at risk.
2. Examination:
1. fundal heights measurements: This was found to be a better discriminator of fetal growth retardation than both the biparietal diameter and serum oestrial ( Chattingius, et. al.: 1983 )^[21]. Decreased girth circumference is a warning sign.
2. weight loss due to:
1. diminished liquor
2. fetal weight loss
Maternal weight loss was a bit of a dilemma here. While weight loss alone was not seen as a significant indicator of fetal compromise, many authors note that it may be a result of decreasing amniotic fluid volume and decreasing fetal subcutaneous fat due to the aging of the placenta (placental insufficiency - see Section IV:B) and thus of some significance. Varney writes that " postdates babies are large babies accompanied by continuing increase in fetal and maternal weight gain where as post mature babies are small babies with fetal and maternal loss."^[22] While trying to decide what should be written in this paper in regards to this assessment, hypothetical cases were discussed and for all cases we determined that with or with out indication, maternal weight gain or loss did not affect our decision or choices. Birthing Services Review from Victoria mentions that routine weighing has not been reliable predictor of fetal well-being and Enkin, et. al. recommended the abandoning of routine weighing of the mother during pregnancy.^[23],^[24]
3. palpation:
1. amount of amniotic fluid : oligohydramnios is recognised by the " molding " of the uterus around the fetus, being easily able to outline the baby, and finding the fetus not ballotable.
2. engagement and position of baby to determine the nearness to labour.
4. communication: exploration of emotions as mentioned above ( Section IV: Contributing Factors; D)
2. Extra Assessment
1. CTG ( cardiotocograph ) also called Contraction Challenge Test, Contraction Stress Test ( CST ), and Oxytocin Challenge Test: There are obvious risks involved in CTGs such as premature labour, fetal distress, etc. (For a full description of these assessments, please refer to Edwards and Simkin's "Obstetrical Tests and Technology - Consumer Guide", 1991 edition, HO.M.E. Manual.) The CTG may be suggested if other test suggests a compromised baby.
2. Non-Stress Testing ( twice weekly ) (For a full description of these assessments, please refer to Edwards and Simkin's "Obstetrical Tests and Technology - Consumer Guide", 1991 edition, HO.M.E. Manual.) According to Elizabeth Davis, there is no definite correlation between NST result and fetal outcome ^[25] .However, no references were given in her conclusion. Another study concluded that breast stimulation testing was proved to be a satisfactory alternative to the oxytocin challenge test, and was less time consuming and was simpler to perform.^[26] NOTE: Some practitioners and authors consider nipple stimulation to come under contraction stress testing ( CTG ) and somewhat interventive, whereas other practitioners and authors list nipple stimulation under non-stress testing. For the purpose of this paper I will list it under non-stress testing as I do not consider it invasive nor as an artificial stimulation or oxytocin.
3. Kick Chart at 42 weeks: Fetal activity is slowed down with placental insufficiency, infection, certain malformations, due to fetal conservation of needed energy for vital functions in a weakened state. Fetal Kick charts are considered more effective than serial estriol tests as an indication of fetal health . A study in Zimbabwe found that the fetal kick chart had a very high predictive value both for the well-being and jeopardy of the baby.^[27] ( See Appendix B )
4. Lab Tests:
1. Serial Estriol Level Determination: A measurement of estriols in either the blood or the urine is compared with the established normal values for the time in gestation, and therefor considered as an indication of the functioning of the fetoplacental unit. It is important to note that there is a wide range of normal values between women and variation in the daily values of the same women so that a single measurement of estriol levels is useless and that a series of values is needed in order to assess the well-being of the fetus and to determine if there is any compromised fetoplacental functioning.
2. Amniocentesis for L/S ( lecithin-sphingomyelin ) ratio
3. Human Placental Lactogen (HPL): a hormone produced by the placenta. Its levels may be checked in order to determine placental health.
5. Biophysical Profile: Description: A series of tests measuring five factors relating to the fetal/placental well-being, each factor given 0 - 2 points. Four of these factors are measured using ultrasound testing, the fifth factor, fetal movement, uses the Non-Stress Test. Occasionally 8 factors are used ^[28]:
1. biparietal diameter
2. fetal movement
3. heart rate pattern
4. muscle tone
5. amniotic fluid volume
6. placental grading
7. height-weight ratio of baby (ponderal index)
8. breathing movements
Note: A prospective trial was conducted to compare the advantages of routine inductions of postdated pregnancies of which 402 pregnancies were studied . 207 (51% ) were allocated to conservative management, and 195 (49%) had routine induction. The amount of amniotic fluid (columns ) were ultrasonically measured (in centimeters) in 196 of the mothers in the conservative group. Three patients had columns of amniotic fluid of less than 3 cm. Two of these required cesareans for fetal distress in early labour ^[29] . According to Frye, this test is very difficult to perform and is very unreliable She claims that "Individually, the tests have a false positive rate of up to 50%, but when done together this decreases considerably."^[30] Then again according to Mills, James and Spade ^[31] , the biophysical profile was considered a superior predictor of acute or chronic fetal asphyxia over the non-stress test.
Various studies looked at the advantages, disadvantages and out come predictiveness of the above methods of assessments if you choose to undergo these investigations. The aim of antenatal care is to monitor the well-being of mother and fetus, and to detect early signs of possible problems. Without the use of ultrasound technology or other intervention, mother and midwife should be able to monitor for at least oligohydramnios and decreased fetal movement quite easily and accurately.
8. THE GREAT DEBATE: To Induce or Not to Induce


In the literature reviewed, the one major debate was whether the active management, i.e. - artificial induction after 42 weeks ) or conservative management, ( i.e. - leave nature to run its course, ) with a variety of techniques for monitoring fetal well-being, would give the best outcomes. Best outcomes were mostly seen in terms of perinatal mortality, but also as lowered rates of operative intervention. Gibb et. al. (1982) ^[32] notes that an induction with an unripe cervix clearly showed a dramatic increase in cesarean sections. Granados (1984)^[33] and Lagrew & Freeman (1986) ^[34] recommend that induction not be attempted without a favourable cervix. It would appear that almost routine induction around 42 weeks is widely practiced in Australia, and is documented as the most usual management in the UK and U.S.A., most authors and studies do not agree with such policies. It is possible that the decision to induce is due to social and legal pressure as there does not appear to be much scientific research to approve of such management.

Schneider, et. al. (1990) ^[35] state that if there is a nonreactive non-stress test accompanied by a favorable biophysical profile then the pregnancy could continue without induction particularly in the situation of an unripe cervix.

Cardozo, Fysh and Pearce (1986) ^[36] after conducting a controlled randomized study found no evidence to support the view that women with normal pregnancy should undergo routine induction at 42 weeks.

In the International Journal of Childbirth Educators , "ICEA Review : Induction of Labor in Postterm Pregnancy" by Halperin and Enkin (1988) , the authors ask a series of questions: Does routine induction of labor for postterm pregnancy reduce the risk of perinatal mortality and morbidity? Does a policy of induction result in an increase in the amount of pain that a labouring woman experiences? They felt that these questions remained unanswered in that there were not enough randomized studies done of a sufficient size and concluded "that both management regimes appear to be safe for the mother and fetus, but they advocate delivery at 42 completed weeks.^[37]

Bergsjø (1985) cites several studies in which routine induction had led to increased cesarean rates, and of all the studies he quotes, concludes that the arguments in favour of induction have not been too convincing. He found that "perinatal mortality is at its lowest from 40 to 44 completed weeks....The so-called postmaturity syndrome of the newborn is an expression of chronic malnutrition, a process which is not confined to the post-term period. It has never been convincingly shown that elective induction of labour at or past term is of benefit...On the other hand, inductions may result in more operative deliveries than would otherwise be necessary." (our emphasis) And finally he concludes that: "more randomized studies on post term policy are clearly needed."^[38] In Birth Reborn , Michel Odent states that it is exceptional for women at his Birth Centre in Pithiviers to be induced for prolonged pregnancy. If they are certain that the pregnancy is prolonged, amnioscopy is performed every 36 hours. If liquor is clear and of good volume, labour is awaited patiently. If liquor is low in volume or meconium stained, induction is performed for multiparas and cesarean section for primiparas. However, Satin and Hankins (1989) warn that "cesarean delivery rates will substantially increase if an amniotomy is performed in the woman with an unfavourable cervix"^[39]

Clark (1989) in the discussion of "Intrapartum Management of the Postdate Patient" advocates induction, rupture of membranes, and placement of scalp electrode if clinically appropriate, then goes on to mention the recently described use of saline amnio-infusions to relieve cord compression caused by low liquor volume! Somewhat contradictory in practice!^[40]

In Human Labor and Birth, Oxorn and Foote write that "recent studies have not confirmed the belief that the fetus has a special intolerance to labor in that there appears to be no greatly increased incidence of variable or late decelerations of the FHR (fetal distress). In most cases the post term fetus tolerates labor well and fetal death is an infrequent event." They go on to recommend that women should be "monitored frequently and even minor signs of fetal distress to be taken seriously and preferred conventional management (no induction) pointing out the usual concerns with inductions; Increased cesareans, fetal distress, stating that routine induction does not improve fetal outcome and recommended induction only for signs of deterioration of fetal health. In their opinion, there was no need for over-aggressiveness and no justification for intervention without documented fetal distress.^[41]

In A guide to Effective Care in Pregnancy and Childbirth (1990) ^[42] the authors, as many other authors and researchers, write that "the results of even large studies using observational data shed little light on the question [of induction]." Their research challenges the more commonly held opinion that inductions led to a rise in c-sections although they considered that the characteristics of the women who participated in these trials were more likely to have a favorable outcome, i.e. - ripe cervix. "Elective delivery, either at term of after 42 weeks, reduces the risk of meconium stained fluid. No other effects, food or bad , have bee established." They not that depressed apgar does not appear affected either way. Well-determined and documented fetal maturity was essential prior to induction. Their recommendation was 2 to 3 day check-ups after 42 weeks. "There is some evidence that these tests (amnioscopy or amniocentesis) can detect pregnancies in which there is 'something wrong', but less evidence that their use improves outcome." Their final conclusion was that in most cases "prolonged pregnancy probably represents a variant of the normal, and is associated with a good outcome regardless of the form of care given. In a minority of cases there is an increased risk of perinatal death and early neonatal convulsions...[one] option [in determining a "plan of action"] is to discuss the currently available evidence with the mother and allow them to decide between elective and selective induction."

Elsewhere , Porto , as a final word of caution, in his paper suggests that "Informed consent should be strongly considered prior to employing any cervical priming techniques. Involving the patient in this process should improve communication and understanding between doctor and patient, which ultimately leads to better care."^[43]

9. PLAN OF ACTION
1. Conservative (no induction) Course:


After 42 weeks gestation, the following assessments may be included or given extra consideration in the antenatal check-up:

1. Nutritional assessment: As the major concern with postmaturity is placental insufficiency, the mother's diet is of utmost importance. (See H.O.M.E. manual Diet Analysis, Section 8:12)
2. Fetal Kick Chart (See Appendix B)
3. Exploration of emotions, i.e. - corns, fears, family stresses, other reasons for possibly "hanging on to pregnancy" (See section VI, D)
4. Non-Stress Testing
5. Evening Primrose 500 mlg 3 times daily to ripen cervix: There have been over 300 extensive scientific investigations into Evening Primrose Oil (EPO) and Gamma Linoleic Acid (GLA). EPO contains high levels of GLA which necessary for the body in the production of prostaglandins, which play an important role in the ripening of the cervix and the initiation of labour. ^[44],^[45], ^[46]
6. Pregnancy tincture containing Blue and Black Cohosh and Squawvine in equal quantities and taken 10 drops/3x day. ^[47] (CAUTION: Blue Cohosh, caulophyllum thalictroides, may lower blood pressure.)
7. Review of mother's history:
1. normal Last Menstrual Period or implantation spotting
2. length of menstrual cycle (longer than 28 days?)
3. previous postdates (mother or her mother?)
4. other reasons for delayed ovulation
8. CTG if other findings are causes for concern
Antenatal check-ups may be performed twice weekly.

If, after discussing significance of findings, it is felt that the baby should be induced the following methods and/or procedures can be taken:

2. Active Management - induction


Before actual induction is begun, the condition of the cervix needs to be assessed for "readiness". Induction with an unripe cervix is far more likely to failure thus leading to fetal distress, maternal distress an exhaustion and increased cesarean rates.

1. Determine the Condition of the Cervix:
1. Bishop Score: Definition: A method of assessing the readiness of the cervix using a 10-point system grading 5 factors, each factor given scores of 0 - 2 points:
1. cervical position : is it pulled forward (anterior), backward (posterior) or toward either side?
2. degree of effacement : thinning of the cervix which is measured in percentiles, i.e. - 50% ( halfway thinned) or 100% effaced ( completely thinned)
3. application of presenting part : how well the baby's head (or whatever part of the baby's body is first entering the pelvis) is pressed against the cervix
4. dilation greater than 2 cm.
5. ripeness of cervix : is the cervix very soft and spongy
Note: Harris et al.^[48] suggests that dilation, effacement and station were more important parameters for determining cervical status than position or consistency.
2. If the cervix does not seem "ready" for labour then the following can be used to further prepare the cervix for labour / induction:
1. sexual intercourse: semen contains prostaglandins which will help ripen the cervix. Maternal orgasm stimulates uterine contractions.
2. prostaglandin gel (inserted either into the vagina or directly to the cervix): again, there is much discussion as to the effectiveness of prostaglandin gels, some lending support for its use, others finding no significant improvement. Thus additional studies are needed.
3. Evening primrose oil : 500 mgs. 3 times daily or applied directly to the cervix [Note: GLAs are not stored . Every tissue makes prostaglandins as needed and therefore improve cervical condition when applied directly.^[49] (See Section IX:1-e for further discussion of evening primrose oil and GLAs.)]
4. Herbal pregnancy tonic as above described
5. Homeopathics: Caulophyllum, Gelsemium, or Pulsatilla depending on the individual picture. ^[50]
3. Conventional Methods of Induction:
1. "strip and stretch" (stripping the membranes) : a technique used to induce labour by placing a finger within the cervix and running it around the inside and separating the membranes (bag of water) from the lower uterine segment thus stimulating the release of prostaglandins in order to initiate labour. It is virtually unstudied though widely practiced.^[51] Risks would include increased risk of infection, and premature rupture of membranes.
2. pitocin drip (administered in hospital) : an intravenous drip containing an oxytocic drug used to induce labour. For a complete explanation please refer to Obstetric Tests and Technology of the H.O.M.E. Manual.
3. laminaria tents : a sponge-like seaweed, laminaria digitatas or japonica that has been in use for over a century to dilate the cervix through expansion while absorbing moisture. Porto (1989) states that laminaria are very effective in the dilation of the cervix, but points out that there is an "alarmingly high rate of infectious complications including a 12% [newborn] rate..." this probably being the result as laminaria can only be partially sterilized. A synthetic alternative has recently been introduced yet further study is warranted.^[52]
4. foley catheter : a catheter that is inserted into the cervix with a small 30 ml. balloon which is inflated and placed on traction by taping it to the mother's thigh. It is gradually pulled through the cervix (approximately 1 hour later) and thereby induces labour. Porto (1989) writes that there was no increased rate of infection.^[53]
Porto further writes "although some encouraging data can be found for the use of mechanical dilating techniques to prime the cervix for induction, further study is clearly required to establish their safety.^[54]

 
4. Alternative Methods of Induction:
1. acupuncture or acupressure
2. enema
3. 2 hourly nipple stimulation with or without sexual intercourse and maternal orgasms
4. 20 drops pregnancy tonic, 4 hourly, combined with a homeopathic remedy: Caulophyllum, Cimicifuga, Pulsatilla, Gelsemium, or Ignasia depending on the individual picture. ^[55]
5. castor oil cocktail:
• recipe I: 100 mls castor oil, 100 mls. orange juice, 1 tsp. bicarb. or soda . Combine all ingredients into tall glass and stir until the "brew" begins to froth (hence the tall glass). Drink while still frothing.
• recipe II: 25 mls castor oil in juice with a pinch of bicarb of soda for 3 consecutive hours (100 mls in all - may be given with or without bourbon or brandy to relax mother). During the middle hour give a slow, high enema. Walking or hot shower for other hours. May take as long as 6 hours for labour to begin.^[56]
WARNING: Castor oil will also cause the baby to pass meconium and will be indistinguishable from meconium staining as a sign of fetal distress. Also known to precipitate spontaneous rupturing of the waters (amniotic liquor) without starting contractions. [Editor: There has been discussion on the list about this, and nobody seems to have any sources that confirm a causal relationship between castor oil and meconium.]
10. VARIOUS PRACTICES AND POLICIES AMONG HOMEBIRTH PRACTITIONERS


Most practitioners and authors seem to adopt a " wait and watch " approach. In addition to what has been above mentioned in the section entitled "The Great Debate" the following recommendations or practices have been listed.

In the Homebirth Australia Newsletter ^[57] practicing midwives Jane Thompson, Sheryl Sidery and Joy Argent made contributions to a Midwives Forum on postmaturity. In Jane's practice she recommends to her mothers who are approaching the end of their 42nd week second daily CTGs. If there was any concern regarding the disproportion between the fetal skull and mothers pelvis she suggests ultrasound, X-ray and CAT scan to allay any fears concerning a baby to big for the mothers pelvis. She may suggest an ultrasound to determine estimated due dates. If there are any concerns about the babies well-being and/or there has been a drastic reduction in fetal movements she would then attempt mild forms of inductions such as nipple stimulation, castor oil, enema, internal examination ( strip and stretch ? ) and acupuncture. ( These methods and other methods of induction are discussed more thoroughly in the following section ).

Sheryl writes that she " would become concerned when the gets to more than 43 weeks or if there are decreased fetal movements, I would ask the woman to be conscious of kicks every hour or so."

Joy finishes up with her belief that the babies know when there ready to come and that if there are concerns by the mother she would utilize a kick chart or " homemade non-stress test ".

Marion Toepke McLean, ^[58] a practicing midwife in the U.S.A. has a policy of hospital delivery for post 42 pregnancies. " Our policy is careful surveillance of post-dates babies, inducing labour only when there are signs of problems or when the mother has good dates and a favourable cervix and prefers induction ( often around 42 weeks ). She emphasises, as do many other authors, the importance in obtaining a good menstrual, obstetric and birth control history, ruling out circumstances which may delay ovulation, with an aim to confirm when the actual date is. Her protocol calls for a non-stress test twice a week when a mother is ten days overdue. At 42 weeks post due she orders a biophysical profile. " If the amniotic fluid levels are significantly reduced we induce even if the other signs are good. . . We have found that our induction failure rate has been reduced by admitting the mother to the hospital the night before her scheduled induction so that she can be given intra-vaginal prostaglandin gel. . .(to) soften the cervix. . . sometimes labour will start on its own before we even administer pitocin."

Dr. John Stevenson, homebirth doctor from Victoria (Australia) with attendances of births in the thousands, writes of a mother in his care who had gone to 44 1/2 and had refused an induction. She continued on to have a quick labour, strong baby and healthy, soft placenta. He continues on to say that since then, " I have had quite a number who went past 44 weeks, and a few who got to 48 weeks. . . . . I oppose induction for post-maturity and advocate patience. . . . (it is) my belief that induction is more dangerous than waiting for baby to turn labour on when it is ready."^[59]

Co-author of this paper, Julie Bullard, believes in twice weekly antenatal care after 42 weeks with the additional observations: fetal kick chart, counseling, special consideration of girth and fundal measurements, and non-stress testing with listening to the FHR without external stimulation,(i.e., nipple stimulation or uterine massage). If there appeared to be indications for termination of pregnancy, Julie preferred home induction using sex and nipple stimulation and careful regular FHR monitoring during labour. She would be prepared to transfer to hospital with meconium staining in combination with irregularity in the FHR.

In my practice I have also maintained a "wait and watch" routine with twice weekly check ups including the above mentioned observations as Julie, with the addition of nipple stimulation or uterine massage for external stimulation of the fetus. I might include a combination herbal tincture, homeopathics, and maybe evening primrose or homeopathic Gelsemium if needed oil as previously described if I feel that the possibility of a home induction may soon become indicated. Neither of these natural remedies are effective if the uterus isn't ready. Labour will not commence prematurely as is the risk with synthetic oxytocin induction. I have no exact number of woman I have cared for who have gone past 42 weeks, but at a guess about a dozen or so. Generally, neither the parents nor I have felt a need to induce labour and we have waited for the baby to "get on with it" at his/her own pace with no complications. One mother decided at 43 weeks that she had had enough a desired to induce naturally. We used an "intensive" program combination of increasing the dosage of pregnancy tonic she had already been taking to every 2 hours*, alternating with Caulophyllum 200 every alternating hour so that she was taking something every hour. She began this routine in the afternoon and into the night until she ceased taking the tonic feeling she had reached saturation point, continuing only with the homeopathic. By the morning she began having mild to moderate contractions throughout the day until the next evening when they became strong and regular.

In another situation, not one of postdates, but where we felt a need induce the labour, the same intensive program was started in the later afternoon with a very ripe cervix. By 4:30 a.m., contractions were happening and the baby was born before 9 a.m.

* I have adopted the policy with herbs or other natural medicines of listening to your own body's signals for determining individual dosages. I start with a general dosage and ask mothers to determine if they feel they need to increase, decrease, or cease remedies. I find this to be very successful.

11. MANAGEMENT DURING LABOUR


The management of prolonged pregnancy once labour has started focuses on careful observations and regard for signs of problems which might have been regarded more lightly at term. Observations include:

1. Fetal heart rate for any abnormalities as discussed
2. Liquor - meconium staining is more likely to be thick due to a possible decrease in liquor. The routine suctioning of a baby with meconium liquor is controversial and does not necessarily prevent meconium inhalation. A further discussion on the topic of meconium staining is found in the H.O.M.E. Manual, Vol.1, "Meconium Liquor".
3. Anticipation of shoulder dystocia if the baby is big, and skillful prompt management of this serious situation.
Management of labour in a hospital setting is likely to be termed "high-risk". Most hospitals in Australia have a policy of induction at 42 weeks including:
1. induction by use of pitocin drips
2. rupturing of the membranes
3. electronic fetal monitoring ( external or internal ) are standards applied (see Obstetrical Tests and Technology, H.O.M.E. Manual, Vol.1 for further discussions on electronic fetal monitoring).
4. Episiotomy
5. cesarean section
6. early clamping and cutting of the cord
7. nursing of the baby in a neonatal care unit
You need to be aware of your options as these questions arise.
12. CARE OF THE POSTMATURE BABY


As previously mentioned, PMS is largely a concern for the babies well-being. Thus there may be special considerations in regards to postnatal care for the newborn.

1. Meconium Staining:


If meconium was present in the amniotic liquor, then possible problems with meconium aspiration may result leading to:

1. asphyxia
2. respiratory distress syndrome - difficulty in breathing (see Glossary)
3. infections
4. pneumonia
These need to be carefully considered and special care and observation may be applicable.

NOTE: For a more detailed discussion of meconium liquor and meconium aspiration, please refer to the H.O.M.E. Manual, Vol. 1, Section 4:2 - "Meconium Liquor")

2. Hypoglycemia in the Newborn:


If placental insufficiency was a problem, the baby may be more prone to hypoglycemia (low blood sugar)^[60] due to reduced fat stores (Glucose is vital to the brain). Also metabolism of glycogen stores due to stress in labour may have been affected. Signs of hypoglycemia include:

1. tremors
2. irregular breathing
3. cyanosis (blue skin colour)
4. lethargy (typically the baby refuses to wake & feed)
5. inability to regulate body temperature
6. convulsion
7. high pitched, weak cry
8. apnea
9. limpness
10. poor feeding
11. change in muscle tone
12. eye rolling
13. sweating
Anne Frye writes that in her experience lethargic symptoms are the first to occur and recommends the following when caring for a newborn with hypoglycemia: ^[61]
1. Hypoglycemia may be checked for at home with Visidex Glucose strips (blood glucose testing strips) following the package instructions. This may be monitored through regular blood tests in hospital. It may be a good idea to collect the babies cord blood at birth (many midwives do this on a regular basis) in the event that blood tests are required. (This may prevent the need to take blood samples from the baby). Transport baby to hospital is showing marked symptoms (but be careful not to read into everything). If not too severe and the baby is still basically okay than baby may be cared for at home.
2. Encourage frequent breastfeeding: Breastfeeding as soon as possible and regularly is important with the malnourished newborn. If the baby is hypoglycemic, symptoms may not stop until the baby feeds. It may be necessary to use an eye dropper to encourage the baby to suck and may take an hour or so the first time. WARNING: do NOT use bottles or rubber teats as these confuse the baby who may be more reluctant to take the breast.
3. Dehydration: may become a concern if the baby is too weak or refuses to feed. Try using an eye dropper until the baby is strong enough to suck. Should be done hourly until the baby feed independently. If the milk is not yet in, you may try water with molasses ( 1 tsp. of molasses to a cup of water ) if necessary as an alternative to transporting to hospital and intravenous fluids and tube feeding. WARNING: do not give the newborn honey or corn syrup as they may carry botulism.
4. Check glucose levels hourly, unless improvement is obvious. Persist with artificial feeds if there is no improvement. If no improvement in a few hours, Frye recommends a pediatric evaluation.
If the baby is feeding and not vomiting, the blood sugar should respond unless something else is interfering.
13. STATISTICS


The following are statistics for pregnancies with a gestation of 42 weeks or more as published in "Home Births in Australia":^[62], ^[63]

	1985-1987		1988-1990
DETAILS:	numbers	%	numbers	%
Total Number of Postdates Pregnancies	280	10.7	251	10.7
Postpartum Hemorrhage Greater than 500 ml.	29	12.4	33	16.5
Cesarean Section Rates	14	5.0	19	7.6
Hospital Transfer
mothers during labour	48	17.1	45	17.9
mother postpartum	1	0.4	6	2.4
newborns	10	2.3	8	3.6
total transfers	59	21.1	59	23.5
Apgar of less than 4 at 1 minute	6	2.3	8	3.6

14. SUMMARY


The issue of prolonged pregnancy is a rather complex one with very little conclusive findings. There have not been enough randomised studies in which to formulate any strong conclusion. The issue of prolonged pregnancy is further confused by the many terms and definitions, which in fact have specific meanings and characteristics. While there may be many reasons for going beyond the estimated due date, incorrect estimation of the due date and a normal variation of human gestation among them, postmaturity syndrome is specific and not always a result of going past due.

Careful assessment and surveillance of the fetus for any compromise is called for. In addition to simply knowing a fetus has passed 42 weeks gestation, diagnosis needs to be made of:

• an unusually small or large fetus
• falling and low amniotic fluid volume
• decreased fetal movements
• changes to the fetal heart rates pattern
• maternal holistic health: emotional, nutritional, obstetric history, etc.
The decision on whether to induce labour at 42 weeks is also inconclusive. While almost routine induction is widely practiced throughout Australia, U.S.A. and the UK, most authors and researchers found little evidence to warrant such action and recommended careful observation and surveillance with closer observation during labour after 42 weeks of pregnancy. It would appear that good outcomes were to be expected regardless of what decision was made regarding induction.

Even after spending many hours compiling information from many sources, we feel we are no closer to a definitive answer then when we began this paper. In looking back over our own past care histories, it seemed that we seemed to follow our own intuition being careful to make personal, individualized assessments while being aware of our own limitations and margins of comfort.

It is essential that a woman feels safe wherever she gives birth. Informed parents can make the decisions that are right for them: to induce or not to induce, to deliver at home or in hospital.

APPENDIX A

GLOSSARY

amniocentesis : the collection of amniotic fluid through a long pudental needle that is introduced into the mother's abdomen, then guided through the uterine wall and into the amniotic cavity between the fetus and the placenta.

amnioscopy : the viewing of the amniotic fluid by inserting an instrument (amnioscope) through the cervix permitting direct visualization. May also be performed with a speculum if the cervix has begun to dilate.

amniotic fluid : (liquor) the fluid surrounding the fetus in the uterus; "the waters".

amniotomy : surgical rupturing of the amniotic membranes.

anencephaly : a developmental anomaly with the absence of neural tissue in the cranium.

apgar : a method of determining the newborn's well-being by a point system from 0 to 10, 2 points being given for each category: heart rate, breathing effort, muscle tone, reflex irritability and colour; 0 being a poor score, 10 being good.

apnea : temporary cessation of breathing.

asphyxia : a lack of oxygen; fetal asphyxia results from interference in placental circulation; in the newborn it is the result of respiratory failure.

ballotment : (ballotable) a diagnostic maneuver in which the fetus is manually "rocked" back and forth in the amniotic fluid (this is done externally through the mother's abdomen) and gently rebounds against the "rocker's" fingers.

bimanual palpation : feeling with both hands.

biparietal diameter : a measurement taken of the largest plane of the fetus's skull.

bradycardia : abnormal slowing of the heart rate and pulse.

Braxton-Hicks contractions : light, irregular "warm-up" contractions.

cephalhematoma: a bleeding beneath the periosteum (top layer of bone) of the skull of a newborn infant.

CPD : cephalopelvic disproportion - a disproportion between the fetal head and the mother's pelvis; a term used to imply that the baby's head is too big for the mother's pelvis.

effacement : thinning of the cervix which is measured in percentiles, i.e. - 50% ( halfway thinned) or 100% effaced ( completely thinned).

extrauterine pregnancy : pregnancy occurring outside of the uterus, somewhere in the abdominal cavity.

fetus : term used to name the baby within the uterus.

foley catheter : a catheter that is inserted into the cervix with a small 30 ml. balloon which is inflated and placed on traction by taping it to the mother's thigh. It is gradually pulled through the cervix (approximately 1 hour later) and thereby induces labour.

fundus : the top of the uterus

fundal : pertaining to the fundus.

gamma Linoleic acid : nutrient necessary for the body to produce prostaglandins.

gestation : the duration of pregnancy.

hypoglycemia : (low blood sugar) particularly in babies characterized as macrocosmic or postmature.

hypoxia : a broad term meaning deficiency of oxygen.

intrapartum : during pregnancy.

IUGR : intra-uterine growth retardation - the term used to imply that the baby in utero is not growing at the normal rate.

laminaria tents : a sponge-like seaweed laminaria digitatas or japonica that has been in use for over a century to dilate the cervix through expansion while absorbing moisture.

lanugo : the fine downy-like hair that covers the body of the fetus.

l/s ratio : lecithin/sphingomyelin ration - the ratio between lecithin (a fatty-like substance, phospholipid) and sphingomyelin (one of the major groups of lipids) found in the amniotic fluid. It is used to assess the maturity of the fetal lung. Prior to the 34th week gestation the level of lecithin produced by the fetal lung is less than the level of sphingomyelin. As the lungs mature this ratio is reversed, thus signifying the ability of the baby's lungs to remain inflated during its breathing efforts. The testing of the l/s ratio is important in determining when to induce labour or for elective cesarean section.

macrosomic : of unusually great body size.

malpresentation : abnormal position of the baby in the uterus.

meconium : a blackish-green material found in the intestines of the full term fetus and constitutes the stools passed by the newly born infant for the first few days following birth.

morbidity : the state of illness, disease of injury; the incidence of diseased persons in relation to a specific population.

mortality : death rate; the incidence of death in relation to a specific population.

multipara : (multip) a woman who has previously had babies.

oligohydramnios : the abnormal deficiency of amniotic fluid; lack of amniotic fluid.

ossification : the formation of bone substance; the hardening of the fetal skull.

palpate : to examine by touch or feeling.

palsy : paralysis.

perinatal : the period shortly before and shortly after the birth.

placenta previa : when the placenta is implanted in the lower uterine segment covering the cervix either completely, partially or marginally.

PNMR : perinatal mortality rate - the death rate during the perinatal period; the ratio of total number of perinatal deaths to the total number of population.

primipara : (primip) a first time mother.

prostaglandin : a fatty acid found within the tissues of the uterus, membranes, semen, etc. and acts as a hormone; when in adequate quantities it causes strong contractions and dilation.

respiratory distress : difficulty in breathing,

saline amnio-infusion : the infusing of a saline solution into the amniotic fluid in order to increase the volume of amniotic fluid; used in oligohydramnios.

scalp electrode : an electrode that is clipped into the fetus's scalp to monitor the heart rate.

"strip and stretch" (stripping the membranes) : a technique used to induce labour by placing a finger within the cervix and running it around the inside and separating the membranes (bag of water) from the lower uterine segment thus stimulating the release of prostaglandins in order to initiate labour. It is virtually unstudied though widely practiced.

shoulder dystocia : an obstruction during the delivery of the baby's shoulders after the birth of the baby's head.

subcutaneous fat : the layer of fat found beneath the layers of skin.

subdural hematoma : a collection of blood or bleeding into the outermost membrane covering the brain and spinal cord (dura mata).

tachycardia : the abnormal sudden rise of the heart rate and pulse.

trimester : a period of three months. Gestation is divided into three trimesters: 1st - 1st three months, 2nd - 3-6 months and 3rd - 7 months to birth.

vernix : a cheesy-like substance that covers the body of the fetus.

References

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12. Stevenson, John; personal notes.
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20. Frye A; Understanding Lab Work in the Childbearing Year: A Guide for Practitioners and Consumers of Healthcare in Childbirth; 3rd ed.; 1985; USA; pg.67.
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23. Birthing Services Review of Victoria.
24. Enkin M, et. al; ibid; "Forms of Care that should be abandoned in the light of the available evidence": 363.
25. Davis, E; Heart and Hands: A Midwifes Guide to Pregnancy and Birth; 1987; 2nd edition; Celestial Arts; USA; pg. 53.
26. Barkai LS, Rabinovici J, Masshiach S;Am. J. of Obstet. & Gynecol.; Nov. 1987; Vol. 157:5 1178-1181.
27. De Muylder X; "The kick chart in high-risk pregnancies: a two year experience in Zimbabwe"; Int. J. Gyn/Ob ; 1988, 27:353-357.
28. Varney, H; ibid.
29. Cowley P, O'Herlihy C, Boylan P; "The value of Ultrasound measurement of amniotic fluid volume in the management of prolonged pregnancies"; Br. J. Obstet.Gynaecol.; 1984; No. 91: 444-448.
30. Frye,A; ibid.
31. Mills, James & Spade; Am. J. Obstet. & Gyn.; July 1990; 163:1:1; 12-17.
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36. Cardozo, L; ibid.
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38. Bergsjø P; 1985; 130.
39. Odent, M; Birth Reborn;
40. Clark SL; "Intrapartum management of the postdate patient"; Clin. Obst.-Gyne.; June 1989; 32:2 278-283.
41. Oxorn H, et. al.; ibid.
42. Bakketeig LS, Bersgjo P; ibid.
43. Porto M; "The unfavorable cervix : methods of cervical priming"; Clin. Obst.-Gyne.; June 1989; Vol.32:2; 267.
44. Manku, MS, Horrobin DF, Morse, N; "Reduced Levels of Prostaglandin precursors in blood of the atopic patients"; Prostaglandins Leukotrienes, Med.; 9:615-28; 1982.
45. Bullivant V; Herbs: Modern Uses for Age Old Remedies.
46. Frye A; ibid.
47. Frye A; ibid.
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49. Manku; ibid.
50. Moskowitz, R; Homeopathic Medicines for Pregnancy & Childbirth; North Atlantic Books, USA, 1992:202
51. Porto M; ibid: 262
52. Porto M; ibid: 263
53. Porto M; ibid: 263
54. Porto M; ibid: 264.
55. Moskowitz, R; ibid.
56. Weed S; Wise Woman's Herbal for the Childbearing Year; Ash Tree Publishing; USA 1989, 59-61
57. Midwives' Forum: Postmaturity"; Homebirth Australia; 1990: No. 26: 19-20.
58. McLean MT; "Post-dates pregnancy"; Midwifery today ; 1989; No. 11:16.
59. Stevenson, Dr. John; personal notes.
60. Frye A; ibid:185.
61. Frye A; ibid:457.
62. Bastian, H, Lancaster, PAL; Home Births in Australia : 1985 - 1987; National Perinatal Statistics Unit, Sydney, April, 1990.
63. Bastian, H, Lancaster, PAL; Home Births in Australia : 1988-1990; National Perinatal Statistics Unit, Sydney, 1992.

APPENDIX B [not available]

The author of this paper is anonymous, and the original date of publication is lost - probably sometime around 1998.  You could cite this paper as

Detailed Paper about PostDates, Anonymous, circa 1998, collected in the Midwife Archives at gentlebirth.org, editor Ronnie Falcao, LM MS