Inadequate Gestational Weight Gain Among Saudi Mothers and Pregnancy Outcomes: Riyadh Mother and Baby Follow-Up Study (RAHMA Explore)

<b>Background:</b> Gestational weight gain (GWG) is commonly used as an indicator of nutritional adequacy during pregnancy and a marker for pregnancy outcomes. This study aims to report the prevalence and extent of GWG inadequacy among Saudi women and to examine the effects of GWG inadequacy on pregnancy outcomes. <b>Methods</b>: This study was conducted as part of the Riyadh Mother and Baby Multicenter Cohort Study; it included 6984 women with singleton pregnancies. Adverse pregnancy outcomes-including hypertension, gestational diabetes (GDM), cesarean section (CS), low birth weight (LBW), Neonatal Intensive Care Unit admission (NICU), and macrosomia-were compared between women with adequate and inadequate GWG, based on the Institute of Medicine (IOM) guidelines. <b>Results</b>: Of the participants, 2221 women (31.8%) had adequate GWG for prepregnancy BMI, 2959 (42.4%) had inadequate GWG, and 1804 (25.8%) had excessive GWG. Women with normal prepregnancy BMI and inadequate GWG had significantly increased odds of delivering LBW infants (adjusted odds ratio (AOR) = 1.61, 95% CI: 1.17-2.20). Inadequate GWG also decreased the odds of emergency cesarean delivery among women with obesity (AOR = 0.75, 95% CI: 0.56-0.97) and lowered the likelihood of NICU admission for infants of obese women (AOR = 0.59, 95% CI: 0.36-0.97). Women with prepregnancy obesity experienced the highest rate of adverse outcomes; however, the prevalence of all adverse outcomes decreased as the degree of weight gain inadequacy increased. Conversely, underweight women had the highest percentage of LBW, with this percentage increasing as weight gain inadequacy increased. <b>Conclusions:</b> The effects of inadequate GWG vary depending on maternal prepregnancy BMI and the specific outcome assessed. For women with obesity, reduced weight gain during pregnancy may be beneficial. In contrast, inadequate GWG is associated with a higher incidence of LBW in women with normal prepregnancy BMI and underweight women.