How common is substantial weight gain after pregnancy?

Area of Science:

• Obstetrics and Gynecology
• Reproductive Health
• Public Health

Background:

• Population studies suggest average inter-pregnancy weight gain of 1-2kg.
• Women with obesity frequently link weight gain to childbearing.
• Limited contemporary data exists on inter-pregnancy weight gain across body mass index (BMI) categories.

Purpose of the Study:

• To investigate inter-pregnancy weight changes in women.
• To analyze weight changes in relation to maternal BMI categories.
• To provide data from a tertiary obstetric hospital in Melbourne, Australia.

Main Methods:

• Retrospective review of 19,617 women's electronic health records.
• Inclusion criteria: aged ≥20 years, ≥2 consecutive singleton births at ≥37 weeks' gestation.
• Logistic regression analyzed weight gain (≥4kg/m²) in relation to first pregnancy BMI, adjusting for covariates.

Main Results:

• 7.5% of normal weight, 10.5% of overweight, and 13.4% of obese women gained ≥4kg/m² between pregnancies.
• One in five normal weight women transitioned to overweight or obese BMI categories after their first pregnancy.
• Higher BMI in the first pregnancy was associated with greater inter-pregnancy weight gain.

Conclusions:

• Substantial inter-pregnancy weight gain is common across various BMI categories.
• Inter-pregnancy weight gain is linked to complications in subsequent pregnancies and long-term maternal health.
• Managing weight gain during and between pregnancies is crucial for preventing adverse maternal and offspring health outcomes.