Caesarean delivery is associated with a higher risk of severe complications for the mother compared with vaginal delivery, especially in women aged 35 and older, research* published in CMAJ (Canadian Medical Association Journal) shows.
Caesarean delivery has become more common over the last 20 years so to understand if caesarean deliveries are associated with severe maternal complications, French researchers used a sub-cohort of a larger study (the EPIMOMS study) to compare 1,444 women who experienced severe complications after delivery with 3,464 controls who did not experience complications, in six French regions. They controlled for factors that might influence the findings, adjusted for baseline risk, and excluded women with pre-existing health conditions that could lead to complications.
The researchers found an increased likelihood of severe complications after delivery among women who delivered by caesarean, whether surgery was performed before or during labour, especially for women aged 35 and older. Although severe maternal complications are uncommon overall, the study found that, for women under 35, the odds of having severe complications after a caesarean delivery were about 1.5 times those following a vaginal delivery, and for women older than 35 the odds were almost twice as high.
Most severe maternal complications involved haemorrhage after delivery; the ability of the uterus to contract reduces with advanced maternal age.
Dr Diane Korb, an obstetrician and epidemiologist with the Robert Debre Hospital and INSERM, Paris, France, said the results had implications for clinical practice.
"Physicians must consider this increased risk when determining the best way to deliver, especially for older mothers," she said.
She added that the results also raise questions about the practices of some obstetricians who perform caesarean deliveries because of advanced maternal age, perhaps with the idea that there will probably be no future pregnancies.
"This practice should be modified to avoid unnecessarily exposing women older than 35 to the risk of severe acute maternal morbidity," said Dr Korb.
The authors acknowledged that their results may be confounded by the health condition that required the caesarean.
"Maternal complications may be the result of the condition that led to the caesarean delivery rather than from the surgical procedure, producing an apparent association between caesarean delivery and maternal complications," Dr Korb explained.
*Korb D, Goffinet F, Seco A, et al. Risk of severe maternal morbidity associated with cesarean delivery and the role of maternal age: a population-based propensity score analysis. CMAJ, April 01, 2019: 191 (13) E352-E360; DOI: 10.1503/cmaj.181067