MONTREAL (FRONTLINE MEDICAL NEWS) – The risk for unplanned cesarean delivery is increased when maternal gestational weight gain exceeds the recommended amount – as it does in almost half of pregnancies in the United States.

In a new analysis of data from the Infant Feeding Practices Study II (IFPS II), women with excessive gestational weight gain (GWG) were found to have an adjusted odds ratio of 1.61 for unplanned cesarean delivery, compared with women with adequate GWG (95% confidence interval, 1.11-2.33; P = .013).

The study, said first author John Francescon, was the first to link excess GWG with the risk of having a cesarean delivery that was not planned. “Despite being a life-saving procedure, it’s still associated with short-term and long-term complications,” he said in an interview during a poster session at the annual meeting of the North American Primary Care Research Group.

Maternal obesity is known to be a risk factor for cesarean delivery, at least in part because excess adipose tissue may interfere with the normal ability of the cervix to thin and dilate with contractions, said Mr. Francescon, a medical student at Ohio University Heritage College of Osteopathic Medicine, Athens. Labor can be prolonged, and it’s often difficult to monitor fetal activity with external activity, he said.

To see whether unplanned cesarean deliveries were associated with excess GWG, Mr. Francescon and his collaborators included data from 2,107 of the 3,033 respondents to the IFPS II , excluding those with missing data and those with planned cesarean deliveries.

Weight gain was grouped into three categories – adequate, inadequate, and excessive – according to guidelines set by the Institute of Medicine. The odds of an unplanned cesarean delivery were adjusted by using multivariable analysis that took into account ethnicity, education, poverty status, parity, and previous obstetric history. The statistical analysis also accounted for the presence of gestational diabetes and the type of birth attendant.

A total of 1,038 women (49.3%) had excessive GWG according to the IOM guidelines, and 287 women (13.6%) overall had an unplanned cesarean delivery. After adjusting for the potentially confounding variables, only excessive weight gain was significantly associated with the risk for unplanned cesarean delivery; those with inadequate weight gain had an odds ratio of 1.03 (95% CI, 0.63-1.69; not significant).

The risk of unplanned cesarean delivery was reduced for women who did not have an obstetrician as a birth attendant, but rather were attended by a nonobstetrician physician or a midwife, said Mr. Francescon. After excluding patients who planned to have cesarean deliveries, 257 of 1,385 (15.6%) of patients seeing obstetricians had unplanned cesarean deliveries; this figure was 9% for nonobstetrician physicians and 4.1% for midwives/nurse midwives.

“This finding suggests that psychosocial factors, such as the bond formed between caregiver and patient, could also potentially influence birthing patterns,” wrote Mr. Francescon and his collaborators.

“Our study findings are supported by previous studies that found increased likelihood of cesarean delivery among women with excessive GWG,” said the investigators.

The study had a large sample size, used well-tested survey instruments, and could include many variables in statistical analysis, all strengths, wrote Mr. Francescon and his coauthors. However, there remained the potential for volunteer bias and recall bias. In addition, weight gain carries social stigma, which could have influence the self-reported results.

“Gestational weight gain is a modifiable risk factor for unplanned cesarean delivery,” Mr. Francescon said. He and his collaborators propose that a comprehensive plan of dietary and lifestyle modifications beginning pre-conception, together with enhanced patient and provider awareness of the risk of unplanned cesarean deliveries with excess gestational weight gain, could help reduce the number of unplanned cesarean deliveries.

The data for the study were provided by the Centers for Disease Control and Prevention. Mr. Francescon reported no conflicts of interest.

SOURCE: Francescon J. NAPCRG 2017 Abstract P495.