It has long been known that C-sections are safer for babies than vaginal birth. Now a new study on maternal request C-sections shows that they may be safer for mothers.
As the Times of London explains, Cesarean section no riskier for mother or baby:
Women who plan to have a caesarean section are no more likely to suffer poor medical outcomes for mother and baby following birth than those who opt for a vaginal delivery, a study has found.
The Canadian research, which looked at more than 400,000 low-risk pregnancies, found hints that women popularly characterised as “too posh to push” might even be better off.
Why might that be? Because although a C-section is surgery, vaginal birth has many risks for mothers as well as for babies.
The right to choose a C-section should be respected not merely for ethical reasons, but because they are safer.
The paper is Birth outcomes following cesarean delivery on maternal request: a population-based cohort study just published in the Canadian Medical Association Journal.
Women may prefer CDMR [Cesarean Delivery on Maternal Request] for many reasons, including scheduling convenience, anxiety regarding labour pain, perceptions that the quality of obstetrical care is better for women who have cesarean deliveries, and concerns about possible urinary incontinence and sexual maternal care and obstetricianbased antenatal care.
It has been difficult to study outcomes of CMDR because they make up such a small proportion of births, for example less than 4% of C-sections in Ottawa. This study is especially compelling because it includes so many women.
A total of 422 210 pregnancies met our inclusion criteria, of which 1827 (0.4%) and 420 383 (99.6%) were categorized as planned CDMR and planned vaginal delivery (including unplanned cesarean deliveries), respectively.
Our cohort included 46 533 cesarean deliveries, of which 1827 (3.9%) were planned CDMR, and 44 706 (96.1%) were unplanned cesarean deliveries. The proportion of all deliveries that were planned CDMR was 0.5% in the first and last fiscal years of our study (2012/13 and 2017/18) and the proportion remained stable across all fiscal years.
Who chooses CMDR? Women who are in a higher risk category than average.
Planned CDMR was associated with late maternal age (≥ 35 yr), being White, living in a neighbourhood of a higher educational quintiles, gaining more than the recommended weight in pregnancy, nulliparity, conception by in vitro fertilization, anxiety, not attending prenatal classes, delivering at a hospital that provides maternal level IIc or III care and receiving antenatal care from obstetricians.
How did the authors evaluate outcomes?
The primary outcome was the Adverse Outcome Index (AOI), a composite of 10 adverse events related to labour and delivery. 33,34 The AOI is reported as the percentage of individual patients with at least 1 adverse event relative to the total number of deliveries. As the AOI may be influenced by dominant outcomes, it cannot be used as an exclusive measure of quality and safety. For this reason, we also measured the Weighted Adverse Outcomes Score (WAOS) and the Severity Index (SI). The WAOS reflects a combination of the frequency and severity of events, and the SI evaluates the severity of adverse events among the pregnancies with an adverse event.
What were the results?
Overall, the AOI was lower in women with planned CDMR (3.8%) than those with planned vaginal deliveries (8.3%) (Table 3). The frequencies of adverse maternal and neonatal outcomes were both lower for women with planned CDMR than those with planned vaginal deliveries. The most common maternal adverse outcomes were unanticipated operative procedures (1.2%, n = 21) for women who planned CDMR, and third-or fourth-degree perineal tear (3.3%, n = 13 686) for women who planned vaginal deliveries. Admission or transfer to the neonatal intensive care unit (NICU) was the most common neonatal outcome for both the planned CDMR and planned vaginal delivery groups…
The WAOS was lower in women with planned CDMR than in those with planned vaginal deliveries (mean difference [MD] −1.28, 95% CI −2.02 to −0.55) (Figure 2), largely because of a lower neonatal WAOS score (MD −1.35, 95% CI −2.00 to −0.69). There was no statistically significant difference in the overall severity of adverse outcomes as measured by the SI between women with planned CDMR and planned vaginal deliveries (MD 3.6, 95%CI −7.4 to 14.5). However, the severity of maternal outcomes was greater for planned CDMR than planned vaginal deliveries (MD 20.1, 95% CI 10.6 to 29.7).
These graphs illustrate the results:
The authors conclude:
…[W]e found that planned CDMR was accompanied by a decreased risk of adverse outcomes. The AOI and WAOS were lower for women with planned CDMR than women with planned vaginal deliveries, and the risk of adverse outcomes was lower after adjusting for confounding factors.
What about previous studies that claimed to show that C-sections are riskier for mothers? Most did NOT look at C-sections on maternal request but on C-sections for which the authors could not find a medical indication on the birth certificate. But it is only by checking the medical record that they could know whether there was a medical indication or not.
The results confirm what we’ve always known: childbirth is inherently dangerous. It has a natural neonatal mortality rate of approximately 7% and a natural maternal mortality rate of approximately 1%. Although modern obstetrics mitigates the risk, vaginal birth is still dangerous. For example, in this study:
– 14 women in the vaginal delivery group died compared to zero in the CMDR group.
– 100 women in the vaginal delivery group sustained a uterine rupture, but none in the CMDR group.
– And 13,686 women in the vaginal delivery group suffered a 3rd or 4th degree tear compared to zero in the CMDR group.
Does this mean that C-sections are always safer than vaginal birth? No, because this study looked only at non-emergency C-sections that were chosen in advance. C-sections done for medical indications are more dangerous than those done electively and the comparison with vaginal birth might yield different results.
But the study DOES mean that women who choose CMDR are making a request that isn’t merely consistent with their right to bodily autonomy but is certainly safer for their babies and also safer for themselves. The right to choose a C-section should be respected not merely for ethical reasons, but — as this paper demonstrates — for medical reasons as well.
