Preconceptional maternal weight loss and hypertensive disorders in pregnancy: a systematic review and meta-analysis

Background Hypertensive disorders of pregnancy (HDP), including pregnancy-induced hypertension (PIH), Preeclampsia (PE), Hemolysis Elevated Liver enzymes and Low Platelets (HELLP) and chronic hypertension, are leading causes of maternal and perinatal morbidity and mortality. Although the pathophysiology of HDP is complex, preconceptional weight reduction in obese women might reduce these complications. We conducted a systematic review and meta-analysis to investigate the effectiveness of preconceptional weight loss by lifestyle intervention or bariatric surgery in overweight and obese women and the reduction of the risk of HDP. Methods and results Databases are searched until September 2019 resulting in 2547 articles: 110 full-text analysis and 29 detailed analysis. Reduced risks were shown for HDP in seven articles (n = 4381) of weight loss after lifestyle intervention or bariatric surgery (OR range 0.10-0.64), for PIH in four articles (n = 46,976) (OR range 0.14-0.79), and for PE in seven articles (n = 169,734) (OR range 0.14-0.84). The stratified analysis of weight loss after lifestyle intervention and bariatric surgery shows comparable results. The meta-analysis of 20 studies of the effectiveness of lifestyle intervention and bariatric surgery revealed reduced risks of HDP (OR 0.45 (95% CI 0.32-0.63)), PIH (OR 0.61 (95%CI 0.44-0.85)) and PE (OR 0.67 (95%CI 0.51-0.88)). Conclusions Preconceptional weight loss after lifestyle intervention or bariatric surgery is effective in reducing risks of HDP, PIH and PE, and emphasizes the need to optimize weight in overweight and obese women with a child wish. More research is recommended to investigate short-term and long-term beneficial and harmful side-effects of these interventions on maternal and offspring health.