Comparison of Gestational Weight Gain and Pregnancy Outcomes in Chinese Women with Singleton Pregnancy Using Standard of Recommendation for Weight Gain during Pregnancy Period and Guidelines by the Institute of Medicine

Background Adequate gestational weight gain (GWG) is critical for maternal and child health. The Institute of Medicine (IOM) standard has long been adopted in clinical practice to guide GWG in China. Since October 2022, China has officially promulgated and adopted the Standard of Recommendation for Weight Gain during Pregnancy Period (WS/T 801-2022) (herein after referred to as SRWGPP) to guide GWG. Objective To compare the distribution of GWG recommended by the SRWGPP and IOM used for Chinese singleton pregnant women and associated adverse pregnancy outcomes, providing clinical evidence for further application of the SRWGPP. Methods The data of this study were from a prospective cohort study involving singleton pregnant women who gave birth in Beijing Obstetrics and Gynecology Hospital, Capital Medical University from May 2020 to September 2021 and participated in the Beijing Birth Cohort Study (registration number: ChiCTR220058395) . Baseline information was collected from the participants, and the incidence of pregnancy complications and outcomes was obtained from the clinical health record system. We compared the distribution of GWG of the participants based on the criteria by the SRWGPP and the IOM guidelines. Then we divided the participants into five groups: insufficient weight gain (IOM+IW) , insufficient weight gain+appropriate weight gain (IOM+IW+AW) , appropriate weight gain (IOM+AW) , appropriate weight gain+ excessive weight gain (IOM+AW+EW) , and excessive weight gain (IOM+EW) . The risk of adverse pregnancy outcomes〔large for gestational age (LGA) , small for gestational age (SGA) , macrosomia, low birth weight, and preterm birth〕 was analyzed after adjusting for confounding factors. Results A total of 11 839 singleton pregnant women were included. The proportions of women with insufficient, appropriate, and excessive GWG were 36.7% (4 339/11 839) , 38.9% (4 601/11 839) , and 24.5% (2 899/11 839) , respectively, according to the IOM standard, and were 16.2% (1 913/11 839) , 45.0% (5 332/11 839) , and 38.8% (4 594/11 839) , respectively, according to the SRWGPP. The proportions of pregnant women in groups of IOM+IW, IOM+IW+AW, IOM+AW, IOM+AW+EW and IOM+EW were 16.2% (1 913/11 839) , 20.5% (2 426/11 839) , 24.6% (2 907/11 839) , 14.3% (1 694/11 839) and 24.5% (2 899/11 839) , respectively. The results from multivariate Logistic regression analysis showed that the risk of overall adverse pregnancy outcomes in IOM+AW+EW group was higher than that in IOM+AW group〔aOR=1.23, 95%CI (1.07, 1.41) , P