Perinatal Outcomes After Sleeve Gastrectomy Compared to a Matched Control Group

Pregnancy after sleeve gastrectomy is increasingly common but outcomes data are limited.

To evaluate perinatal outcomes following sleeve gastrectomy compared to a matched non-bariatric control group with similar pre-pregnancy BMI.

We undertook a retrospective cohort study (2016-2022) of pregnant women with prior sleeve gastrectomy (n = 520) versus no bariatric surgery (n = 58 777). Following matching for maternal age, pre-pregnancy body mass index, parity, smoking, Australian vs. overseas-born and delivery year, there were 469 post-sleeve gastrectomy and 915 matched control pregnancies. The main outcome measures were gestational diabetes, gestational hypertension/preeclampsia, large-for-gestational-age (LGA) and small-for-gestational-age (SGA) infants, perinatal mortality, preterm birth, neonatal unit admission, major congenital anomalies and caesarean births. Outcomes' assessment utilised univariable and multivariable conditional logistic regression models, conditioned by matching strata. Surgery-pregnancy interval impact was separately explored.

Compared with matched controls, post-sleeve gastrectomy pregnancies had a lower risk of gestational diabetes at 5.4% vs. 16.6% (aRR 0.26 (95% CI: 0.14-0.45)), gestational hypertension/preeclampsia 1.1% vs. 6.1% (aRR 0.24 (95% CI: 0.08-0.69)), LGA infants 6.0% vs. 14.1% (aRR 0.34 (95% CI: 0.20-0.58)), and neonatal unit admission 13.9% vs. 19.0% (aRR 0.67 (95% CI: 0.47-0.98)), but almost double the risk of SGA infants 14.5% vs. 8.3% (aRR 1.92 (95% CI: 1.22-3.04)). Surgery-pregnancy interval < 12 months versus ≥ 12 months was associated with greater likelihood of inadequate gestational weight gain but no outcomes' differences.

Pregnancy following sleeve gastrectomy carries increased SGA risk, possibly due to unrecognised hypoglycaemia and/or nutrient deficiency. These pregnancies require additional patient education, nutrient monitoring and supplementation, and fetal surveillance.