Objectives: American Institute of Medicine (IOM) recommends different ranges of gestational weight gain (GWG) based on pre-pregnancy body mass index (BMI). In Taiwan, IOM guidelines are implemented concurrently with the local recommendation for GWG (10–14 kg). This study compared between the two sets of guidelines in relation to adverse perinatal outcomes. Methods: We analyzed 31,653 primiparas with singletons from 2011 to 2016 annual National Breastfeeding Surveys. Logistic regressions for preterm birth, small for gestational age (SGA), large for gestational age (LGA), cesarean section and excessive postpartum weight retention (EPWR) were fitted separately for GWG categorized according to IOM and Taiwan ranges. Areas under the receiver–operator curves (AUC) and the predicted probabilities for each outcome were compared in each BMI group. Results: AUC for both guidelines ranged within 0.51–0.73. Compared to Taiwan recommendation, IOM ranges showed lower probabilities of SGA for underweight (0.11–0.15 versus 0.14–0.18), of LGA for obese (0.12–0.15 versus 0.15–0.18), of EPWR for overweight (0.19–0.30 versus 0.27–0.39), and obese (0.15–0.22 versus 0.25–0.36); and higher probabilities of EPWR for underweight (0.17–0.33 versus 0.14–0.22). Conclusions for practice: Discriminative performance of IOM and Taiwan recommendations was poor for the five adverse birth outcomes, and no preference for either set of recommendations could be inferred from our results. In the absence of specific GWG guidelines, health care workers may provide inconsistent information to their patients. Future research is needed to explore optimal GWG ranges that can reliably predict locally relevant perinatal outcomes for mother and child.