Women who undergo weight-loss operations have a lower risk for cesarean section later on

Obesity during pregnancy puts women at higher risk for complications and can compromise the newborn's health. But obese women who undergo weight-loss (bariatric) operations before getting pregnant significantly lower their risk of cesarean delivery and increase the likelihood of healthy fetal and infant outcomes, according to research findings presented at the 2016 Clinical Congress of the American College of Surgeons.

Obese women are at higher risk of cesarean delivery and other poor outcomes, while their babies are more vulnerable to a wide range of serious health problems. It's well known that women who lose excess weight before they become pregnant increase their chances of healthier pregnancies and perinatal outcomes. Still, the question remained whether pregnancy after a bariatric operation is safer than pregnancy in obese women.

"We know that the prevalence of obesity in women is increasing, so we wanted to know more about the impact of bariatric surgery on pregnancy, the mother, and the baby," said study co-author Samantha Drew, a medical student at the Philadelphia School of Osteopathic Medicine in Suwanee, Georgia. People are increasingly choosing bariatric operations as a way to lose a large amount of excess weight, with the estimated number of these procedures performed annually rising from 158,000 to 196,000 in four years (2011-2015).*

For this study, researchers evaluated maternal and fetal outcomes in pregnancies after women underwent bariatric operations in comparison with pregnancies in obese women who did not have bariatric procedures. Investigators examined studies from a PubMed medical literature search that included comparative data on the maternal and fetal delivery outcomes following bariatric operations. The primary outcome was the rate of cesarean-section (C-section) deliveries in these patients. During a C-section, the baby is delivered through a surgical incision in the mother's abdomen and uterus.

Specifically, researchers pooled data from five studies: 4,329 cesarean sections were recorded in 10,811 post-bariatric women and 133,533 cesarean sections in 223,573 obese women. The researchers found that there was a far lower incidence of caesarean deliveries in women who had a bariatric operation before getting pregnant—1 percent of formerly obese women who had a bariatric procedure versus 38 percent in those who did not.

The study is among the first to examine the interplay between bariatric surgery and pregnancy and maternal and perinatal outcomes. "These findings are important because we were able to confirm that obese women who undergo bariatric operations prior to conceiving do not have worse outcomes compared with obese women who don't have these procedures," said senior study author Aliu Sanni, MD, FACS, an associate professor at Georgia's Augusta University, and medical director of the department of metabolic and bariatric surgery, Eastside Medical Center, Snellville, Georgia. "We want to make sure that bariatric surgery performed before pregnancy will have benefits for these women and that having a procedure won't harm the baby."

Another key finding was that women who had undergone bariatric operations were much less likely to give birth to large babies. Over half of the women who did not have a bariatric procedure delivered babies that were large for gestational age, compared with just 11 percent of those who did have bariatric operations. Further, about 40 percent of the surgery-free women had babies that were very large for gestational age, compared with 25 percent of those who underwent bariatric operations.

"If the child is less at risk of being very large for its gestational age, the woman is less likely to have a c-section," said study coauthor Brittanie Young, a medical student at the Philadelphia School of Osteopathic Medicine in Suwanee, Georgia.

Additionally, obese women who had undergone bariatric operations were significantly less likely to give birth to babies who were small for gestational age—11 percent compared with 45 percent, and also about 10 percent less likely to need assisted vaginal delivery. The incidence of preterm delivery were similar in both groups (4 percent).

"We now have a tool that can be offered to patients that will improve the quality of their life as well as their children," said study coauthor Christoper Ibikunle, MD, FACS, a professor of surgery at Georgia's Augusta University. "We hope the results of this analysis will change practice, because it will allow doctors, midwives and patients to consider bariatric surgery as a safe and very positive step, which was something we did not know before."

Next, the reseachers plan to build on this research and conduct a study that will follow patients who have undergone bariatric surgery to assess their quality of life.