Healthy Gestational Weight Gain Programme

This study aims to evaluate the efficacy of a multi-component lifestyle interventions during pregnancy on promoting appropriate gestational weight gain, preventing GDM, and improving pregnancy, delivery, and neonatal outcomes among overweight or obese pregnant women. The intervention strategies are developed based on the transtheoretical model and mobile health (via WeChat Public Account in smartphone), and will be conducted online and offline. This study will recruit and follow-up 200 overweight or obese singleton pregnant women (pre-pregnancy 24kg/m2≤BMI≤40 kg/m2) during the first trimester of pregnancy from Weifang Maternal and Child Health Hospital, Shandong Province, China, and Tongzhou Maternal and Child Health-care Institution, Beijing, China, with 100 pregnancy women in each institution. The 200 overweight or obese pregnant women will be randomly allocated at a 1:1 ratio to either the intervention or control group, stratified by the categorical variables of age, BMI and parity. Participants in the control group will be provided usual prenatal care. The lifestyle intervention will last for approximately 6 months (from 10-14 weeks to 32-36 weeks of gestation). Follow-up timepoints included 8-14 weeks of gestation, 24-28 weeks of gestation, 32-36 weeks of gestation. The interventions are composed of health education related to gestational weight gain and healthy lifestyles, diet modification, active physical activity, regular individual in-person and telephone sessions, diet behavior monitoring, physical activity monitoring, and weight monitoring with Huawei Wristband and WeChat Public Account. The hypothesis is that lifestyle interventions based on the transtheoretical model and mobile health will result in more appropriate gestational weight gain and lower risk of adverse pregnancy outcomes compared with usual care.

Overweight and obesity is a major public health problem among women in reproductive age. Excessive gestational weight gain (EGWG) among this group is becoming a worldwide epidemic over recent decades. EGWG is associated with adverse outcomes including increased risk of developing gestational diabetes mellitus (GDM), cesarean section, hypertensive disorders of pregnancy (HDP), elevated infant birth weight and adiposity, and increased risk of metabolic syndrome and childhood obesity in offspring. Therefore, interventions are needed to help overweight and obese pregnant women to control GWG.

Lifestyle intervention has been proved effective on weight management during pregnancy. However, the effects of interventions on controlling overweight and obese women's GWG are inconsistent. Traditional face-to-face counseling are less cost effective. Effective intervention models based on Mobile health that can be scaled up are scarce. Thus, this randomized controlled trial aims to identify: firstly, whether the mobile health lifestyle interventions will be effective on improving gestational weight gain and preventing GDM among overweight or obese pregnant women; secondly, whether the intervention will be beneficial for improving pregnancy outcomes, delivery outcomes, neonatal outcomes, metabolic indicators, body composition indicators, etc. among overweight or obese pregnant women.

The interventions are composed of health education (online and offline health education on recommended gestational weight gain, prenatal dietary guidance and physical activity recommendation), diet behavior modification (8 core dietary goal setting and monitoring weekly), active physical activity (150 min per week of moderate-to vigorous-intensity physical activity including aerobic exercise (brisk walking) and resistance exercise; goal of 6000 steps/day), regular face to face or telephone sessions, lifestyle (diet and physical activity behavior) and weight monitoring via Huawei Wristband or WeChat Public Account. Tailoring of the intervention will be guided by the transtheoretical model. A total of 200 overweight or obese singleton pregnant women of 8-14 weeks of gestation will be recruited and they will be randomly allocated at a 1:1 ratio to either the intervention or control group, stratified by the categorical variables of age, BMI and parity. Participants in the control group will be provided usual prenatal care.

Women in both study arms will attend three research appointments at 8-14 weeks (baseline),24-28 weeks (midterm) and 32-36 weeks (terminal) of gestation for data collection via questionnaires, physical measurements, and clinical laboratory examination. Information on demography, socioeconomic status, medical and family history, obstetric history, current pregnancy information, smoking, consumption of alcohol, attitude and knowledge about GWG, diet and exercise habits, sleep situation, quality of life, mental health (depression, anxiety), social support, self-efficacy, etc. will be collected with questionnaires and interviews by research stuff. Physical measurements including weight, height, blood pressure, and body composition using bioelectrical impedance (BIA) will be obtained using standardized methods. Laboratory tests performed in conjunction with antenatal visits include a 75 g 2-hour oral glucose tolerance test (OGTT). Data on mode of delivery, gestational age at birth, birth weight, Apgar scores, perinatal complications, etc. will be obtained from patient records. In addition, blood and urine samples will be drawn at three appointments and a sample of cord blood will be collected at birth. Maternal postpartum weight (42 days,6 months,1 year after delivery) will be obtained through routine physical examination or telephone follow-up. Offspring physical growth indicators, such as height, weight, head circumference, etc., will be collected from routine physical examination in 42 days, 6 months and 12 months of age.

Eligibility Criteria:
Inclusion Criteria:

1. At 8-14 weeks of gestation
2. Overweight or obese (pre-pregnancy 40 kg/m2≥BMI≥24 kg/m2) based on BMI recommendations of the Group of China Obesity Task Force of the Chinese Ministry of Health accounting for interracial differences (overweight BMI 24-28 kg/m2 and obese BMI≥28kg/m2)
3. 18-40 years of age
4. Singleton pregnant
5. Skilled at using smartphones and WeChat during pregnancy
6. Attend regular antenatal care and plan delivery at W.F. Maternal and Child Health Hospital or Tongzhou Maternal and Child Health-care Institution of Beijing
7. No contraindications to physical activity according to Physical Activity Readiness Questionnaire (PAR-Q)
8. Willing to be randomized and cooperate with research and regular follow-up visits and sign informed consent.

Exclusion Criteria:

1. Pre-pregnancy hypertension, severe cardiovascular and cerebrovascular diseases, respiratory disease, hepatic and renal disease, malignant tumors, systemic lupus erythematosus, thyroid disease, severe anemia, and other chronic consumptive diseases.
2. Cervical insufficiency (historical painless cervical dilation leading to recurrent second-trimester births in the absence of other causes; dilated cervix on manual or speculum examination, etc.), multiple pregnancy, or continuous vaginal bleeding, etc.
3. Diabetes before pregnancy
4. Special dietary needs (e.g. , vegetarianism)
5. Severe psychiatric disorders (serious mental health disorders including depression, anxiety, bipolar disorders, etc.)
6. Cognitive impairment, visual impairment or hearing impairment
7. History of bariatric surgery or surgical history involving important organs within 3 months
8. Participated in other clinical trials within 6 months