Pregnant women with prior bariatric surgery experienced 35 surgical complications in a Belgian cohort study.

ObjectiveTo determine the incidence and clinical characteristics of surgical complications during pregnancy in women with a history of bariatric surgery. DesignA nationwide, prospective, population-based cohort study. SettingHigh-risk obstetric care in Belgium: 67.6% of maternity units participated, covering 65% of all births in the study period. ParticipantsPregnant women with a history of bariatric surgery presenting with a surgical complication (internal hernia, intussusception, volvulus or adhesions; anastomotic ulcer or abscess; gastric band slippage; or incisional hernia) between January 2021 and December 2022. ResultsThirty-three women experienced 35 surgical complications. Internal herniation was most common (n=25), predominantly following Roux-en-Y gastric bypass. Mean gestational age at diagnosis was 27+6 weeks. All women underwent surgical exploration within 24 hours; bowel resection was required in two cases. Caesarean section occurred in 48.5%, with 13 preterm births and one neonatal death. One woman required intensive care. No maternal death occurred. ConclusionSurgical complications following bariatric surgery in pregnancy are uncommon but carry significant obstetric risks. All observed complications occurred after procedures involving intestinal rerouting, predominantly Roux-en-Y gastric bypass. Prompt surgical management was associated with low maternal morbidity and no mortality, but frequently resulted in preterm birth and emergency caesarean section. These findings highlight the need for a low threshold for surgical evaluation of abdominal pain in pregnant women with previous bariatric surgery and suggest that procedure type is relevant when counselling women of reproductive age. Strengths and limitationsO_ST_ABSStrengthsC_ST_ABS- Nationwide, population-based cohort study to evaluate surgical complications during pregnancy following bariatric surgery. - Case identification was performed through the Belgian Obstetric Surveillance System (B.OSS), using active prospective monthly reporting. Cases were compared with national hospital discharge data to assess potential underreporting. - National health insurance data were used to estimate the total number of pregnancies following bariatric surgery to provide procedure-specific denominators. Limitations- The small number of cases limited statistical power and precluded formal comparisons between different bariatric procedures. - Despite its strong network, the B.OSS methodology is vulnerable to underreporting due to the voluntary participation of clinicians.