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Vaginal Births after C-section are safer in  Birth Centers in certain situations

by Judy Slome Cohain, CNM

Abstract: Recent research concluded that VBACs are riskier in a birth center than in the hospital. This conclusion is only true if the woman is sure she will not have any more pregnancies following the VBAC attempt and if she does not suffer from “Fear of Hospitals.”  The childbirth center study had an 87% VBAC rate, whereas US hospitals had a 28% VBAC rate during the same time period, and presently have a 10% VBAC rate. The woman attempting a VBAC in hospital has a high risk of a repeat cesarean.  Additional pregnancies after a repeat c-section, have significantly increased risks of neonatal death and stillbirth. judyslome@hotmail.com

 
The results of the National (US) Study of Vaginal Birth After Cesarean in Birth Centers(1) made the following blanket statement: Vaginal births after c-section are riskier in a birth center than in the hospital. This conclusion did not take into consideration women who will have further pregnancies after their attempted VBAC and/or women who suffer from fear of delivering in hospital. One of the authors of the study, Judith Rooks, explicitly wrote, "The authors of the National Study of Vaginal Birth after Cesarean in Birth Centers did not attempt to quantify the effects of our recommendations on perinatal mortality in future pregnancies." (2)

Their analysis is valid only for the group of women who will not have more pregnancies and are not afraid of hospitals.

But, not all women are sure the birth following their c-section will be their last pregnancy. In addition, experienced practitioners agree that fear of hospitals affects outcomes. Therefore, the conclusions of the study do not apply to all women and the study should not have been the basis for changing protocols.  Instead, the data should be used to help women make informed choices.

A review of the current literature regarding VBAC outcomes for women who are planning to have more children or who have fear of hospitals, along with the data provided by The National Study of Vaginal Birth After Cesarean in Birth Centers clearly demonstrates that having a VBAC in a childbirth center is less risky than delivering in hospital.

The Birth Center study involved 1353 low-risk women who attempted VBAC in childbirth centers. They were compared to 21,000 low-risk women who attempted VBAC in four different hospital-based studies.

The researchers concluded that in the childbirth centers, the perinatal mortality rate for low-risk women attempting VBAC was 1/500 whereas the perinatal mortality rate for low-risk women in the hospitals used for comparison (like Brigham and Women's Hospital, of Harvard Medical School which has a laudable 13.5% c-section rate for first births, including breech births) was 1/1000. Low-risk women were defined as women having only one previous cesarean and delivering before 42 weeks. The study data implies that one baby of the 1353 who were studied  in the childbirth center research would not have died if all of the1353 women who attempted VBACs  in childbirth centers had delivered in one of the specific hospitals where the comparison hospital research was carried out. It must be pointed out that not all women in childbirth center study had access to large teaching hospitals like Brigham and Women's Hospital. Hospitals vary widely in their VBAC outcomes.  For example,  the risk of neonatal death due to uterine rupture while attempting VBAC was found to be 3.4 times greater in hospitals with less than 3,000 births per year(1per1,300) than in  hospitals with more than 3000 births per year(1per4,700)(3)).

The United States national hospital repeat c-section rate in 1995 was 72%. (4). This is more than 5 times the 13% repeat c-section rate found among the  births studied in US childbirth centers from 1990 – 2000(1). In hospitals today, 90% of women who attempt VBACs are given repeat c-sections(7). In subsequent pregnancies after two cesarean surgeries, there is a much higher rate of life-threatening complications to both mother and baby.  For example, the neonatal mortality rate for women with a history of two c-sections attempting a VBAC is 2% or 1/50(1).

The pregnancy after one or more cesareans has an increased risk of the placenta growing into the uterus  (which often ends with hysterectomy), placenta previa, and uterine rupture.  In pregnancies following two c-sections a woman has a 3% risk of uterine rupture or five times the risk of uterine rupture for a woman with one scar. Among women who experience uterine rupture, about 20% will require a hysterectomy. The risk of third trimester unexplained stillbirth on second births is 1 per 1000 pregnancies for women who had a first birth vaginally and 1 per 500 for women who had a cesarean first birth(5). No one has researched the unexplained stillbirth rate after two or more c-sections(6).

If no further pregnancies happen after the VBAC, the hospital VBAC presumably saves 1 baby per thousand more than in childbirth centers.   When the mother plans further pregnancies, the dramatically higher repeat c-section rate for hospital births increases rather than decreases the risk to the mother and baby overall, because of the increased risks on future pregnancies. For the 90% of women who have a repeat c-section, their next pregnancy will have at least double the risk of the baby dying as an unexplained stillbirth late in the third trimester, plus added risk of maternal mortality and morbidity before and during the repeat cesarean surgery. It is unfortunate that as a rule, women are not informed of these risks by their doctors.

In addition, the population of women who deliver in childbirth centers is very different from the hospital population. At least some  of the women who have good outcomes in childbirth centers would have disastrous outcomes in the hospital due to anxiety and fear. To date, the syndrome “Fear of Hospitals” has yet to be listed as an official diagnosis although most experienced practitioners have noticed the syndrome in clients who arrive with a good labor pattern, which stops or slows down dramatically after entering the hospital.   “Fear of Labor” is a well studied and often written about diagnosis. "Fear of Labor" is treated with an elective cesarean section.  "Fear of Hospitals" remains an officially unrecognized diagnosis. Women with "Fear of Hospitals" do not progress in the hospital. When labor does not progress in the hospital, it is generally treated with labor augmentation, such as pitocin or prostaglandins. Labor induction and augmentation after a cesarean section is known to be increase the occurrence of uterine rupture and neonatal mortality. The women who pathologically fear hospitals are logically the ones who seek out alternatives to hospitals. These women have better outcomes outside of the hospital, where their labors can progress unhindered by anxiety of hospitals.

How do we know what would have been the outcomes of the 1353 VBAC births in the childbirth centers if they had delivered in hospitals? The answer is: we don’t. At present this is the only data we have for out-of-hospital VBAC outcomes. It is inadequate to be the basis of changing current protocols, Unfortunately many hospital based midwifery services no longer offer VBACs. As a result of this research, nor do childbirth centers.  The women seeking VBACs have the choice of either a 10% chance of a successful VBAC in hospital or to have a VBAC at home.

Research-based conclusions that can be drawn are:

1. A woman with a low-risk pregnancy should deliver her first birth with a trained midwife or doctor, who has a documented c-section rate of 4% or less for low-risk women. She should deliver in a place where she is comfortable. A woman with  “fear of hospitals” syndrome should be particular about having her first birth in an optimally welcoming environment with a low c-section rate.

2. Women with one cesarean scar should be informed that:

a. They are taking an increased risk of 1/1000 of losing the baby if they deliver outside of the hospital, and

b. They have an increased risk of a repeat c-section by delivering in hospital, which will increase their risk of losing the baby by more than 1/1000 on the next pregnancy.

 

References:

1.       Lieberman E., et al. 2004. Results of the national study of vaginal birth after cesarean in birth centers. Obstet Gynecol. Nov. 104(5 Pt 1): 933-42.

2.       Letter from Judith Rooks to Judy Slome Cohain April 20, 2005

3.       Smith GC et al. 2004. Factors predisposing to perinatal death related to uterine rupture during attempted vaginal birth after caesarean section: retrospective cohort study. BMJ 329 (7462):375.

4.       Goer, H. 1999. The Thinking Woman’s Guide to a Better Birth. New York: Perigee Books, p. 162.

5.       Smith GC, Pell JP Dobbie R. Caesarean section and risk of unexplained stillbirth in subsequent pregnancy. Lancet. 2003 Nov 29;362:1779-84.

6.       Personal communication with G.C. Smith.

7.       National Center for Health Statistics: http:

Judy Slome Cohain, CNM (since 1982), MS, is devoted to illuminating the field of women’s health with objective evidence, based on the scientific method.