Abstract Background Bariatric surgery (BS) is increasingly performed in women of reproductive age. While it reduces obesity-related pregnancy complications, the optimal timing of conception post-surgery remains unclear. This meta-analysis assesses maternal and neonatal outcomes following BS and evaluates whether delaying pregnancy for over 12 months after surgery improves outcomes. Methods A systematic search of MEDLINE, EMBASE, EMCARE, and Cochrane databases (2014–2024) identified 129 eligible studies involving pregnancies after BS, including sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), and one-anastomosis gastric bypass (OAGB). Pooled prevalence estimates and odds ratios (OR) were calculated using random-effects models. Subgroup analyses examined outcomes by surgery type and timing of conception (12 versus 12 months post-surgery). Results Bariatric surgery reduced pre-pregnancy BMI by a mean of 14 kg/m2. Compared to obese controls, BS was associated with lower odds of gestational diabetes (OR 0.67, 95% c.i.: 0.53–0.85), pre-eclampsia (OR 0.60, 95% c.i.: 0.45–0.79), and macrosomia (OR 0.35, 95% c.i.: 0.24 to 0.50), but higher odds of intrauterine growth restriction (IUGR; OR 2.09, 95% c.i.: 1.92 to 2.27), NICU admission (OR 1.39, 95% c.i.: 1.17–1.65), and 5-minute Apgar 7 (OR 1.38, 95% c.i.: 1.07–1.79). Gestational weight gain (GWG), gestational hypertension, and post-partum haemorrhage were not significantly different between groups. Anaemia was prevalent (26%, 1218/4685) and micronutrient deficiencies were frequent, particularly in vitamin A (61%, 121/199), vitamin D (69%, 110/160), and iron (33%, 73/220). In subgroup analyses, women who conceived within 12 months of bariatric surgery gained significantly less gestational weight (mean difference 5.07 kg (95% c.i.: 2.53 to 7.60)) compared to those who conceived after 12 months (mean difference 5.07 kg (95% c.i.: 2.53 to 7.60)), but the odds of gestational diabetes and preterm birth were similar between groups. Conclusion Bariatric surgery before pregnancy improves key metabolic outcomes but raises risks of IUGR, NICU admission, and nutritional deficiencies. While delaying conception beyond 12 months increases gestational weight gain, it does not clearly reduce other adverse outcomes. These findings support individualized preconception counselling and close antenatal monitoring. Further prospective studies are needed to refine timing recommendations and improve maternal–foetal care in this population.
Bobotis et al. (Thu,) studied this question.