Maternal body mass index and gestational weight gain and their association with perinatal outcomes in Viet Nam

Abstract

Objective: To examine the association between gestational weight gain and maternal body mass index (BMI) among Vietnamese women and the risk of delivering an infant too small or too large for gestational age.

Methods: A prospective health-facility-based study of 2989 pregnant Vietnamese women was conducted in the city of Nha Trang in 2007-2008. Cubic logistic regression was used to investigate the association of interest. Infants were classified into weight-for-gestational-age categories according to weight centiles for the Asian population. Gestational age was based on the date of last menstrual period and adjusted by the results of first-trimester ultrasound.

Findings: BMI was low (< 18.5), normal (18.5-22.9) and high (≥ 23.0) in 26.1%, 65.4% and 8.5% of the women, respectively. In each of these BMI categories, the percentage of women who delivered infants too small for gestational age was 18.1, 10.0 and 9.4, respectively, and the mean gestational weight gain was 12.5 kg (standard deviation, SD: ± 3.6), 12.2 kg (SD: ± 3.8) and 11.5 kg (SD: ± 4.7), respectively. Among women with low BMI, the risk of delivering an infant too small for gestational age ranged from approximately 40% if the gestational weight gain was < 5 kg to 20% if it was 5-10 kg.

Conclusion: Having a low BMI, commonly found in Viet Nam, puts women at risk of delivering an infant too small for gestational age, especially when total maternal gestational weight gain is < 10 kg.

Figures

Fig. 1

Probabilitiesa of delivering an infant too small or too large for gestational age by gestational weight gain in women with a lowb body mass index (BMI), Nha Trang, Viet Nam, 2007–2008

Fig. 2

Probabilitiesa of delivering an infant too small or too large for gestational age by gestational weight gain in women with a normalb body mass index (BMI), Nha Trang, Viet Nam, 2007–2008

Fig. 3

Probabilitiesa of delivering an infant too small or too large for gestational age by gestational weight gain in women with a highb body mass index (BMI), Nha Trang, Viet Nam, 2007–2008