Science & Sensibility recently published an interview with Melissa Cheyney, one of the authors of the forthcoming “Planned home VBAC in the United States, 2004-2009: outcomes, maternity care practices, and implications for shared decision making.” Reporting on the largest group of HBAC women to date (1052 women), the VBAC rate was 87% overall, rising to 90% in women with vaginal birth before their cesarean and 96% in women with prior VBAC. (Not reported, unfortunately, in either the interview nor the e-pub ahead of print version of the paper is the VBAC rate in women with no prior vaginal births or VBACs.)
HBAC, however, appears to impose greater risk to the baby. The overall mortality rate (deaths during labor or up to 28 days after delivery) was 4.8 per 1000 compared with 1.2 per 1000 in MANA cohort women with prior births and unscarred uteruses. Among the 5 deaths, two were probably related to scar ruptures, making the scar-related mortality rate 1.9 per 1000, but the other 3 were not. One resulted from complications during a twin delivery, the second from an entrapped head in an undiagnosed breech, and the third from umbilical cord prolapse.
The paper describes what happened in the two cases probably related to the scar giving way. One woman birthed vaginally at home, and emergency services were summoned to help with resuscitation efforts and transfer. The other woman was transported to the hospital after an episode of severely abnormal fetal heart rate “where she delivered a stillborn infant by vacuum extraction 35 minutes later” (Cox 2015, p. 5), a statement that raises the question of whether management after transport might have played a role if the baby was still alive at hospital arrival.
If there is increased risk, why, then, would women make this choice? Cheyney thinks that for some women, at least, it may be because they can’t obtain a hospital VBAC. In support of this, she observes that regions of the U.S. such as the Southeast that have low access to hospital VBAC have higher proportions of women planning HBACS than women in Western states such as Oregon, Washington, and California where hospital VBAC is more available.
Based on the MANA stats, the best of both worlds looks to be VBAC in a hospital with VBAC-friendly policies attended by a midwife. That way women could both maximize likelihood of VBAC and safety. Shame on a system that forces women to choose between the short-term, long-term, and reproductive risks of surgery they neither want nor need or the risks of out-of-hospital birth.
