Studies have shown that overweight and obese women are at increased risk for several complications of pregnancy, including gestational diabetes mellitus, hypertension, preeclampsia, and cesarean delivery. Additionally, the children of overweight or obese pregnant women show an increased risk of prematurity, congenital anomalies, and childhood obesity. The Lifestyle Interventions for Expectant Mothers (LIFE-Moms) consortium was a network of seven clinical centers and a data coordinating center to identify effective behavioral and lifestyle interventions that improve weight, glycemic control, and outcomes in obese and overweight pregnant women and their children.

Participants were randomized between 9 weeks 0 days and 15 weeks 6 days gestation, and followed through one-year postpartum. Standardized measures were collected throughout gestation: at baseline (9-15 weeks), 24-27 weeks, 35-36 weeks, delivery, and one-year postpartum. Eligibility criteria, specific outcome measures, and assessment procedures were standardized across trials. Measures that were collected in all seven trials were defined as ‘core’ data and measures collected by four to six trials were defined as ‘super-shared’ data. All core and super-shared measures had a standardized definition and/or detailed procedures to facilitate uniform collection, a standardized training and certification process, and were entered into a common dataset at the data coordinating center.

The overall goal of the consortium was to identify effective behavioral and lifestyle interventions that would improve weight, glycemic control, and other pregnancy-related outcomes in obese and overweight pregnant women and determine whether these interventions reduced obesity and metabolic abnormalities in children.

The primary outcome measure was gestational weight gain per week, assessed by serial weight measurements up to 36 weeks gestation. Secondary outcome measures included obstetric outcomes (e.g., gestational hypertension and preeclampsia, gestational diabetes, preterm delivery), maternal one-year postpartum outcomes (e.g., postpartum weight retention), neonatal outcomes (e.g., birth weight, respiratory morbidity, hypoglycemia), and neonatal and infant anthropometrics (e.g., length, skinfold thickness). Site specific measures can be found in the LIFE-Moms Synopses document.

Core inclusion criteria:

• Singleton viable pregnancy
• Gestational age at randomization no earlier than 9 weeks 0 days and no later than 15 weeks 6 days
• Body mass index (BMI) based on first trimester measured weight and height of 25 kg/m2 or higher (other BMI criteria are site specific)

Core exclusion criteria:

• Maternal age of less than 18 years
• Diabetes prior to pregnancy
• Fetal anomaly
• Planned termination of pregnancy
• History of three or more consecutive first trimester miscarriages
• Past history of anorexia/bulimia
• Current eating disorder
• Actively suicidal
• Prior or planned bariatric surgery
• Current use of exclusionary medications (i.e., metformin, systemic steroids, antipsychotic agents, anti-seizure medications or mood stabilizers that would be expected to have a significant impact on body weight, medications for ADHD including amphetamines and methylphenidate)
• Continued use of weight loss medication
• Contraindications to aerobic exercise in pregnancy
• Participation in another interventional study that influences weight control
• Enrollment in this trial in a previous pregnancy
• Intention to deliver outside a LIFE-Moms consortium hospital
• Unwillingness/inability to commit to a 1-year follow-up

Site specific inclusion and exclusion criteria can be found in the LIFE-Moms Synopses document.

Pooled findings from the LIFE-Moms consortium found that among the randomized women, the percent with excess gestational weight gain per week as well as overall weight gain from enrollment in early pregnancy to 36 weeks gestation, was significantly lower in the intervention group compared to those in standard care. However, the women in the intervention group still exceeded the Institute of Medicine (IOM) guidelines for weight gain in pregnancy. No differences were found between the intervention and standard care groups for macrosomia, cesarean section, gestational diabetes, and small-for-gestational-age infants.