Sarah Stock — from the MRC Centre for Reproductive Health at the University of Edinburgh in the United Kingdom — and her colleagues carried out a review of existing research in the hope to shed some light on the effects of having a cesarean delivery, also known as a C-section, on the health of both the mother and the child.
The findings are significant, given that more and more women are opting for a cesarean delivery instead of a vaginal one – a lot of the time without having been medically advised to do so.
As the authors of the new study report, almost 25 percent of births in Europe and 41 percent of births in North America occur via a C-section.
The researchers note that while pregnant women are usually well-advised of the short-term outcomes of having a cesarean, they are less informed about the long-term impact of a C-section – not only on their health and that of their baby, but also on their ability to carry future pregnancies.
So, Stock and her team set out to examine the main maternal and baby outcomes associated with C-sections. To this end, they reviewed randomized controlled trials and large prospective cohort studies.
In total, the number of participants included in the studies was almost 30 million.
The main outcome that the researchers looked for in mothers was pelvic floor dysfunction, while the main baby outcome studied was asthma, and the main outcome of future pregnancies was perinatal death.
Lower pelvic dysfunction risk for mothers
Stock and colleagues summarize their findings: “We found that cesarean delivery is associated with reduced urinary incontinence and pelvic organ prolapse in the mother but with increased odds of asthma and obesity in the child.”
They add: “Cesarean delivery is associated with future subfertility and several subsequent pregnancy risks such as placenta previa, uterine rupture, and stillbirth.”
More specifically, the risk of urinary incontinence was 44 percent lower for women who chose to have a C-section, and 71 percent lower for a pelvic organ prolapse.
However, children delivered by cesarean were 21 percent more likely to develop asthma within the first 12 years, and 59 percent more likely to become obese by the age of 5.
Women who had a C-section were 17 percent more likely to have a miscarriage if they decided to become pregnant after the cesarean, and 27 percent more likely to experience a stillbirth.
However, the risk of perinatal mortality was insignificant.
The risk of placenta previa, on the other hand — a condition in which the placenta grows in the wrong part of the womb — was 74 percent higher for mothers who had a C-section, and the risk was even higher for placenta accreta or placental abruption.
Significance of the findings
The researchers recognize some of the limitations of their own review. Most studies reviewed were observational, they say, which makes the results prone to bias.
Also, they say, the “observational studies […] were performed in high-income countries. This means that the results should be interpreted with caution, and [the] findings may not be generalizable to other healthcare settings.”
However, the findings are definitely important for women considering a cesarean. The authors conclude:
“These findings might help enhance discussions between clinicians and patients regarding mode of delivery, meaning that patients will be better informed of the potential long-term risks and benefits of cesarean delivery for themselves, their offspring, and any future pregnancies.”
Finally, the observational nature of the studies reviewed also means causality cannot be inferred.