NCT07902232Completed
Gestational Weight Loss and Restrictive Weight Gain in Maternal Obesity: A Target Trial Emulation
Gestational Weight Loss and Restrictive Weight Gain Across Maternal Obesity Classes: A Nationwide Target Trial Emulation in the United States
Source: ClinicalTrials.gov · Last updated 28 Oct 2026
Brief summary (registry, in English)
This study asks whether the current weight-gain guideline for pregnant people with obesity should be lowered, and whether the answer depends on how severe the obesity is. The guideline from the Institute of Medicine (IOM) recommends that all pregnant people with obesity gain 5.0 to 9.0 kg, regardless of obesity class. However, growing evidence suggests that people with Class II or III obesity may benefit from gaining less than this range-or even losing a small amount of weight-without harming the baby. A randomized trial to test this directly would be ethically and practically difficult, so this study uses a different approach: it reconstructs what such a trial would have shown, using nationwide U.S. birth records. The study uses 2024 U.S. birth certificate data for people with pre-pregnancy obesity who had a single live birth. It compares three weight-gain patterns during pregnancy: (1) net weight loss (less than 0 kg gained), (2) restrictive gain (weight gained, but below the dynamic, gestational-age-specific IOM lower bound), and (3) standard gain within the IOM-recommended range. The main questions are whether restrictive gain or weight loss, compared with standard gain, reduces the risk of hypertensive disorders of pregnancy (such as gestational hypertension and preeclampsia) while not increasing the risk of a baby born small for gestational age (SGA). The study also examines whether the balance of benefits and harms differs across Class I, Class II, and Class III obesity. This is an observational study, not a randomized trial. It does not enroll participants or provide treatment. All analyses use existing, de-identified public health data. Results are intended to inform whether future weight-gain guidelines should provide class-specific recommendations rather than a single range for all obesity classes.
- Status (registry)
- Completed
- Study type
- Observational
- Enrollment
- 205636 (actual)
- First submitted
- 18 Oct 2026
- Start date
- 1 Jan 2026
- Primary completion date
- 1 Oct 2026
- Lead sponsor
- Shanghai First Maternal and Infant Health Hospital affiliated to Tongji University Medical School
- Diseases
- Obesity, High blood pressure
- NCT number
- NCT07902232
What you commit to
- Study type: Observational
- Participants enrolled: 205636
- From 1 Jan 2026 to the primary completion date, 1 Oct 2026
- 1 site in 1 country
- Visits and tests: ask the trial team, the registry does not list them
Built from the registry fields of ClinicalTrials.gov. It describes the study, not your situation.
Who cannot take part
Copied verbatim from ClinicalTrials.gov and grouped by topic. Only the trial team decides who can take part.
Other illness
- Pre-existing (pre-pregnancy) diabetes mellitus or pre-existing chronic hypertension (confirmed or unknown status).
- Missing or unknown data on core maternal or neonatal outcomes (gestational diabetes, gestational hypertension, eclampsia, or infant birthweight).
- Any confirmed, suspected, or unknown congenital structural anomaly or chromosomal disorder (e.g., anencephaly, spina bifida, cyanotic congenital heart disease, congenital diaphragmatic hernia, omphalocele, gastroschisis, limb reduction defect, cleft lip/palate, Down syndrome, chromosomal disorder, or hypospadias).
Other
- Biologically implausible or extreme gestational weight gain (GWG) values (\< -10.0 kg or \> +50.0 kg).
Who the study is looking for
- Singleton live births recorded in the U.S. National Vital Statistics System (NVSS) Natality database (2024 cohort for primary target trial emulation).
- Gestational age at delivery between 24 and 41 completed weeks (obstetric estimate).
- Maternal age between 18 and 45 years at delivery.
- Pre-pregnancy obesity defined as BMI ≥ 30.0 kg/m² (excluding unknown code 99.9).
- Early prenatal care initiated in the first trimester (Months 1-3; PRECARE5 recode = 1).
- Maternal race and ethnicity categorized as Non-Hispanic White, Non-Hispanic Black, Non-Hispanic Asian, or Hispanic.
Age in the registry: 18 years to 45 years · Sex: Female
Sites (1)
Sites in registry order. Save your city in your profile to sort them by distance.
| Site | City | Country | Site status |
|---|---|---|---|
| Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine Coordinator of this site? Confirm its status | Shanghai | China | Unknown status |
This page is information, not medical advice. Discuss any trial with your doctor.