Gestational Weight Gain Growth Charts Adapted to Japanese Pregnancies Using a Bayesian Approach in a Longitudinal Study: The Japan Environment and Children’s Study

Abstract

Background Tracking gestational weight gain (GWG) during pregnancy makes it possible to optimize pregnancy outcomes and GWG growth curves are well suitable for this purpose.The GWG guidelines for Japanese were revised in 2021. However, currently, there are no GWG growth curves to guide women on how to gain weight to meet these guidelines.Methods Using data on 96,631 live births from the Japan Environment and Children's Study (JECS), we created descriptive GWG percentile curves estimated the trajectory of GWG required to meet the GWG guidelines stratified by pre-pregnancy body mass index (BMI) For both analyses, Bayesian mixed models with restricted cubic splines adjusted for maternal characteristics were used.Results GWG curves substantially differed by pre-pregnancy BMI, and were higher among multiparas and those with lower maternal age and with no previous disease. We estimated that underweight, normal weight, overweight and obese women who gain 8.4 to 11.1 kg, 6.4 to 9.1 kg, 3.8 to 6.5 kg, and <1.9 kg at 30 weeks of gestation are on the trajectory to reach the new guidelines at 40 weeks of gestation.Conclusions We provide GWG percentiles curves for Japanese women as well as GWG trajectory curves to meet the new GWG recommendations. These results may help pregnant women monitor weight during their pregnancy.

Association between Heated Tobacco Product Use during Pregnancy and Fetal Growth in Japan: A Nationwide Web-Based Survey

“…Age (<25 years, 25–29 years, 30–34 years, 35–39 years, or ≥40 years), pre-pregnancy BMI (underweight < 18.5 kg/m 2 , normal 18.5–24.9 kg/m 2 , overweight 25.0–29.9 kg/m 2 , or obese ≥ 30 kg/m 2 ), and maternal gestational weight gain (insufficient, appropriate, or excessive) were included as basic confounding variables. As the appropriate value for gestational weight gain depends on the pre-pregnancy BMI, we considered both pre-pregnancy BMI and gestational weight gain during pregnancy [ 16 , 17 ]. Thus, we classified the participants into 11 categories as an anthropometric parameter of mothers to predict SGA ( Figure S1 ) [ 17 , 26 ].…”

“…As the appropriate value for gestational weight gain depends on the pre-pregnancy BMI, we considered both pre-pregnancy BMI and gestational weight gain during pregnancy [ 16 , 17 ]. Thus, we classified the participants into 11 categories as an anthropometric parameter of mothers to predict SGA ( Figure S1 ) [ 17 , 26 ]. As socioeconomic and environmental variables [ 14 ], we included household income (<5 million JPY [approximately 50,000 USD], 5 to <8 million JPY, ≥8 million JPY, or unknown), occupation (manager or others), educational attainment (≤12 years [high school] or ≥13 years [college or university]), prefectures where the women resided (prefectures with >5 million population and those with <5 million population), and date of delivery (July 2019–February 2020, March 2020–August 2020, September 2020–February 2021, or March 2021–August 2021).…”

“…Therefore, the specific adverse effects of HTP use during pregnancy on poor fetal growth remain unclear. In addition, the effect of relevant risk factors for poor fetal growth, including maternal pre-pregnancy body mass index (BMI) and weight gain during pregnancy, were not considered [ 15 , 16 , 17 ].…”

“…SGA is associated with the risk of infant mortality and developing future-lifestyle-related disorders, such as hypertension and diabetes mellitus. SGA is also associated with maternal pre-pregnancy BMI and weight gain during pregnancy [ 16 , 17 ]. Therefore, identifying and exploring risks associated with SGA are crucial [ 15 , 21 ].…”

Impact of maternal dyslipidemia on infant neurodevelopment: The Japan Environment and Children’s Study

“…The covariates in our models were selected a priori based on previously published literature [6][7][8][29][30][31][32] and biologic plausibility. Maternal pre-pregnancy BMI was calculated using the mothers' height and pre-pregnancy weight as listed in medical records and classified as underweight (<18.5 kg/m 2 ), normal weight (18.5-24.9), overweight (25.0-29.9), or obese (!30.0) [33]. Gestational weight gain (GWG) was categorized as below, within, or above reference values based on the guidelines of the Institute of Medicine (now known as the National Academy of Medicine) of 2009 [34].…”