More than 40% of reproductive-age women reported having unprotected sex in the year after undergoing bariatric surgery, despite recommendations to avoid pregnancy for at least a year, a new study finds. Another 4% of women reported trying to conceive in the 12 months after surgery.
“We were surprised to find such a large percentage of women were not using contraception, and we were also surprised to find so many were actively trying to conceive,” the study’s lead author, of the University of Pittsburgh, said in an interview. “Reproductive-age women who are considering bariatric surgery should be counseled that they should plan to use contraceptives after surgery for about 12-18 months.”
Pregnancy isn’t recommended over that period mainly because of the risks to the fetus, Dr. Menke said. “These risks are different from obesity in general. We don’t know exactly why surgery causes these risks, but ideally, patients would be weight-stable prior to conception.”
In 2013, the American Association of Clinical Endocrinologists, the Obesity Society, and the American Society for Metabolic & Bariatric Surgery provided a Grade D recommendation for a 12-18 month delay in conception (). A recent study provided more insight into the potential risks of pregnancy soon after weight-loss procedures. It reported that, compared with those who gave birth more than 4 years later, women who gave birth within 2 years of bariatric surgery had higher risks of premature birth, admission to neonatal intensive care units, and small-for-gestational-age infants ( ).
The current prospective cohort study included women who underwent bariatric surgery for the first time during 2005-2009 at 10 U.S. hospitals. The women, all aged 18-44 years, answered questions for as long as 7 years, until January 2015 (Obstet Gynecol. 2017 Oct 6.).
The analysis included 710 women who provided conception data. The median body mass index of the women was 46.3 kg/m2. Most patients underwent Roux-en-Y gastric bypass (73%), followed by laparoscopic adjustable gastric banding (23%).
Researchers found that 4.3% of the women tried to conceive in the first year after surgery (95% confidence interval, 2.4-6.3), and 13.1% did so in the second year (95% CI, 9.3-17.0; P less than .001).
During the first year after surgery, 12.7% of women had no intercourse (95% CI, 9.4-16.0), 40.5% had only protected intercourse (95% CI, 35.6-45.4), and 41.5% (95% CI, 36.4-46.6) had unprotected intercourse while not trying to conceive.
Why are the unprotected sex numbers so high? “We wonder if some women simply feel that they cannot get pregnant,” Dr. Menke said. “Our group has previously reported that 42% of women who had attempted to conceive prior to bariatric surgery had a history of infertility. Some of these women went on to deliver a live birth, but many did not.”
The study reports that 183 of the 710 women did ultimately conceive and that the number may be as high as 237 because data were missing for 54 women who may have not wanted to report a nonlive birth. Of the women who reported conceiving, 68.9% had live births, 1.1% had stillbirths, 1.1% had ectopic pregnancies, 21.9% miscarried and 7.1% had abortions.
“We’d really like this research to be a reason to consider presurgical contraceptive counseling as one of the steps prior to bariatric surgery,” Dr. Menke said. “This may include a referral by the bariatric surgeon to a physician would who provide counseling, prescribe, or both.”
The study was funded by the National Institute of Diabetes and Digestive and Kidney Diseases. Dr. Menke reported having no relevant disclosures. Her coauthors reported financial relationships with pharmaceutical and medical device companies with products to treat metabolic diseases.