Vaginal Births After C-section Are Not Necessarily Riskier in a Birth Center than in the Hospital
by Judy Slome Cohain

[Editor's note: This article first appeared in Midwifery Today Issue 77, Spring 2006.]

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 and if she does not suffer from "Fear of Hospitals." Since childbirth centers offered a VBAC rate of 87%, whereas US hospitals currently offer a VBAC rate of less than 10%, the woman has a much higher risk of a repeat cesarean if she delivers in hospital, which increases her risk on subsequent pregnancies. judyslome@hotmail.com


The results of the National Study of Vaginal Birth After Cesarean (VBAC) in Birth Centers shows that childbirth centers are not necessarily more dangerous than hospitals for women who plan to have more children.

The results of the National (US) Study of Vaginal Birth After Cesarean in Birth Centers (1) has made the following blanket statement: Vaginal births after c-section are riskier in a birth center than in the hospital. If one could be absolutely sure that this will be the woman's last pregnancy and the woman is not afraid of delivering in hospital, the conclusion may be true. However, the conclusions made by this study should not be the basis for changing protocols, but rather for improving the information upon which women base their choices.

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 hospital-based studies.

The researchers concluded that in childbirth centers, the neonatal mortality rate for low-risk VBAC was 1/500 and in hospitals, it was 1/1000. (Low-risk women were defined as women having only one previous cesarean and delivering before 42 weeks.) The study implies that one baby per 1000 will be saved if all of the women who chose childbirth centers had delivered in the hospitals where the hospital research was carried out.

Note: The risk of neonatal death due to uterine rupture in a hospital with less than 3000 births per year is 3.4 times greater than in a hospital with more than 3000 births per year.(3)

Women who go on to have another pregnancy will find that the added safety of the hospital may be outweighed by the risk of having two cesarean scars, due to the higher repeat c-section rate in hospital.

The United States national hospital repeat c-section rate in 1995 was 72%.(2) This is more than five times the 13% repeat c-section rate found among the 1400 births in US childbirth centers from 1990–2000. After two cesarean surgeries, a woman experiences a much higher rate of complications in subsequent pregnancies.

In addition, the neonatal mortality rate for women with a history of two c-sections attempting a VBAC is 20/1000 (2%). By delivering a baby in a hospital a woman might lower her risk of losing the baby by 1/1000, but she raises the risk of losing her baby in subsequent pregnancies to 20/1000 if she attempts a VBAC.

In pregnancies where an attempted VBAC follows two c-sections a woman has five times the risk of uterine rupture (3%) than a woman with one scar, and she risks the placenta growing into the uterus (which ends with hysterectomy), placenta previa and stillbirth. Among women who experience uterine rupture, about 20% will require a hysterectomy. No one has researched the unexplained stillbirth rate after two c-sections.

In addition, the population of women who deliver in childbirth centers is very different from the hospital population. At least some, if not all, of the women who have good outcomes in childbirth centers would have disastrous outcomes in the hospital due to extreme anxiety and fear.

To date, the syndrome "Fear of Hospitals" has yet to be made a diagnosis by the American College of Obstetricians and Gynecologists (ACOG). However, "Fear of Labor" is officially recognized. This unique female pathologic hysteria is treated with an elective cesarean section. Women who fear going to hospitals logically seek out alternatives to hospitals. Since anxiety has been shown to adversely affect the progress of labor, these women obviously have better outcomes outside of the hospital. These are the women whose labors do not progress in the hospital. The treatment they are given is labor augmentation, such as Pitocin or prostaglandins. Labor induction and augmentation after a cesarean section is known to be dangerous and leads to high uterine rupture rates and high neonatal mortality rates.

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 these are the only data we have. This is inadequate to be the basis of changing current protocols. The following research-based conclusions can be drawn:

  1. A woman with a low-risk pregnancy should deliver a first birth with a trained midwife or doctor, who has a documented cesarean section rate of 4% or less, in a place where she is comfortable. A woman with the syndrome of "fear of hospitals" should be particular about having her first birth in a safe environment with a low c-section rate.
  2. Women with one cesarean scar should be informed that:
    1. They are taking an increased risk of 1/1000 of losing the baby if they deliver in a childbirth center, and
    2. They increase their risk of a repeat c-section by delivering in hospital.

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.

References:

  1. Lieberman, E., et al. 2004. Results of the national study of vaginal birth after cesarean in birth centers. Obstet Gynecol 104(5, Pt 1): 933–42.
  2. Goer, H. 1999. The Thinking Woman's Guide to a Better Birth. New York: Perigee Books, p. 162.
  3. Smith, G.C., 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.

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