Comparison of pregnancy outcomes after bariatric surgery by sleeve gastrectomy versus gastric bypass

Objective: Bariatric surgery has an impact on subsequent pregnancies, in particular an association between gastric bypass and small for gestational age. Knowledge is lacking on whether sleeve gastrectomy is associated with more favorable pregnancy outcomes. This study aimed to compare the impact of sleeve gastrectomy and Rouxen-Y gastric bypass on the incidence of small for gestational age (SGA), and of adverse pregnancy outcomes. Study design: We conducted a retrospective study in a single reference center, including all patients with a history of sleeve or bypass who delivered between 2004 and 2021 after their first pregnancy following bariatric surgery. We compared the incidence of SGA, intrauterine growth retardation, preterm delivery and adverse maternal outcomes between patients who had sleeve versus bypass. Results: Of 244 patients, 145 had a sleeve and 99 had a bypass. The proportion of SGA < 10th percentile did not differ between the two groups (38/145 (26.2 %) vs 22/99 (22.22 %), respectively, p = 0.48). Preterm birth < 37 WG was lower in the sleeve group (5/145 (3.45%) vs 12/99 (12.12 %) in the bypass group (p = 0.01), as well as NICU hospitalizations (3 (2.07%) vs 12/99 (12.12%), p < 0.01). There was no difference regarding adverse maternal outcomes such as gestational diabetes and hypertensive complications. The proportion of SGA was not lower in patients with bypass when adjusting for other risk factors (BMI, smoking, geographic origin, diabetes and hypertension) (aOR 0.70; 95%CI 0.01 - 2.85). Conclusion: sleeve was associated with an incidence of SGA which was as high as after bypass, however the incidence of preterm birth was lower.