A history of bariatric surgery appears to both positively and negatively influence pregnancy outcomes, according to a prospective, nationwide cohort study published in the New England Journal of Medicine.
Pregnancies after bariatric surgery, as compared with control pregnancies matched for presurgery body mass index, were associated with a significantly lower risk of gestational diabetes (1.9% vs. 6.8%; odds ratio, 0.25; P < .001) and large-for-gestational age infants (8.6% vs. 22.4%; OR, 0.33; P < .001).
“However, increased surveillance during pregnancy and the neonatal period is warranted, since a history of bariatric surgery was also associated with small-for-gestational-age infants (15.6% vs. 7.6%; OR, 2.20; P < .001), shorter gestation (273 days vs. 277.5 days; P < .001), and potentially an increased risk of stillbirth or neonatal death [1.7% vs. 0.7%; OR, 2.39; P: 0.06],” study author Kari Johansson, Ph.D., from the Karolinska Institute in Stockholm, suggested in the study (N. Engl. J. Med. 2015;372:814-24 [doi:10.1056/NEJMoa1405789]).
The study, thought to be the largest to date comparing 2,952 pregnancy outcomes between women with and without a history of bariatric surgery, found no difference in the risk of congenital malformations between groups. The median time from surgery to conception was 1.1 years.
Dr. Johansson reported support from the Swedish Research Council and a young investigator award from the Obesity Society. Her coauthors reported support from the Swedish Research Council, Stockholm County Council, and consulting fees from Itrim and Strategic Health Resources.