Weight loss prior to pregnancy and subsequent gestational weight gain: Prepare, a randomized clinical trial

• Published in: American journal of obstetrics and gynecology 2021-01, Vol.224 (1), p.99.e1-99.e14
• Main Authors: LeBlanc, Erin S., Smith, Ning X., Vesco, Kimberly K., Paul, Ian M., Stevens, Victor J.
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; behavioral weight loss intervention; Cognitive Behavioral Therapy; Cohort Studies; Electronic Health Records; Female; Gestational Weight Gain; gestational weight guidelines; Humans; obesity; overweight; Pregnancy; Pregnancy Outcome; Pregnancy Trimesters; Prenatal Care; prenatal counseling; prepregnancy; Treatment Outcome; Weight Loss; weight management; Young Adult
• ISSN: 0002-9378; 1097-6868; 1097-6868
• DOI: 10.1016/j.ajog.2020.07.027

Women with elevated body mass index are encouraged to lose weight before pregnancy, but no trials have tested the effects of prepregnancy weight loss on health outcomes. This study aimed to determine whether prepregnancy weight loss reduces gestational weight gain and improves pregnancy outcomes. Pragmatic randomized clinical trial was conducted between May 2015 and October 2019 at Kaiser Permanente Northwest, an integrated health system. Data collection was blind to condition assignment. Eligible participants were women aged 18 to 40 years with a body mass index of ≥27 kg/m2 who were planning pregnancy within 2 years. Recruitment contacts were sent to 27,665 health system members who met age and body mass index criteria; 329 women attended screening visits, and 326 were randomized. They were randomized to either a behavioral weight loss intervention or usual care control. The intervention consisted of health coaching phone sessions weekly for 6 months and then monthly for 18 months or until end of pregnancy. We used logistic regression to examine the a priori primary hypothesis that participants in the intervention would be less likely to exceed National Academy of Medicine guidelines for gestational weight gain during each trimester and overall. Secondary and exploratory outcomes included absolute weight gain before and during pregnancy and perinatal and newborn outcomes. Of the 326 participants, 169 had singleton pregnancies lasting ≥14 weeks (analytical cohort: intervention, 89; control, 80). At baseline, mean age was 31.3±3.5 years, and body mass index was 34.8±5.8 kg/m2. Participants in the intervention group lost more weight before pregnancy than those in the control group (−0.25±0.51 vs −0.03±0.21 kg/wk; P