Independent effect of gestational weight gain and prepregnancy obesity on pregnancy outcomes among Saudi women: A sub-cohort analysis from Riyadh mother and baby cohort study (RAHMA)

Background Gestational weight gain (GWG) and prepregnancy obesity are garnering more attention as determining factors of pregnancy outcomes when it comes to the wellbeing of both the mother and her baby. This study was conducted to describe the pattern of GWG among participants of Riyadh Mother and Baby Multicenter Cohort Study (RAHMA) and to investigate the detrimental effects of excessive GWG and prepregnancy obesity on pregnancy outcomes. Methods RAHMA is a multicentre cohort study conducted in three hospitals in Riyadh, Saudi Arabia. Participants were categorized according to the Institute of Medicine into inadequate, adequate, and excessive GWG, and stratified by body mass index (BMI) into under/normal weight, overweight, and obese. To examine the independent effect of maternal prepregnancy obesity and GWG, a multivariate regression model was used and adjusted odds ratio (AOR) and 95% Confidence Interval (CI) for each outcome were calculated. Results A total of 7029 participants were included in this study; 31.8% had adequate GWG, 25.9% had excessive GWG and 42.3% had inadequate GWG, while 29.7% had normal BMI, 33.3% were overweight, 34.8% were obese, and 2.2% were underweight. Excessive GWG was independently associated with increased risk of hypertensive events, (AOR = 1.77, 95% CI 1.20-2.63). Obesity was associated with higher risk of gestational diabetes (AOR 2.11, 95% CI 1.76-2.53), hypertensive events (AOR 2.06, 95% CI 1.48-3.01), and delivery by emergency caesarean section (AOR = 1.63, 95% CI 1.35-1.97). Infants of obese women had increased odds of macrosomia (AOR 3.11, 95% CI 1.94-4.99) and lower odds of low birth weight (AOR = 0.68, 95% CI 0.53-0.88). Conclusion In comparison to excessive GWG, which increases the risk of hypertensive events during pregnancy, prepregnancy obesity is associated with more adverse outcomes including GDM, hypertensive events in pregnancy and emergency CS.