Gestational weight gain in 4 low- and middle-income countries and associations with birth outcomes: a secondary analysis of the Women First Trial

Abstract

Background: Adequate gestational weight gain (GWG) is essential for healthy fetal growth. However, in low- and middle-income countries, where malnutrition is prevalent, little information is available about GWG and how it might be modified by nutritional status and interventions.

Objective: We describe GWG and its associations with fetal growth and birth outcomes. We also examined the extent to which prepregnancy BMI, and preconception and early weight gain modify GWG, and its effects on fetal growth.

Methods: This was a secondary analysis of the Women First Trial, including 2331 women within the Democratic Republic of Congo (DRC), Guatemala, India, and Pakistan, evaluating weight gain from enrollment to ∼12 weeks of gestation and GWG velocity (kg/wk) between ∼12 and 32 weeks of gestation. Adequacy of GWG velocity was compared with 2009 Institute of Medicine recommendations, according to maternal BMI. Early weight gain (EWG), GWG velocity, and adequacy of GWG were related to birth outcomes using linear and Poisson models.

Results: GWG velocity (mean ± SD) varied by site: 0.22 ± 0.15 kg/wk in DRC, 0.30 ± 0.23 in Pakistan, 0.31 ± 0.14 in Guatemala, and 0.39 ± 0.13 in India, (P <0.0001). An increase of 0.1 kg/wk in maternal GWG was associated with a 0.13 cm (95% CI: 0.07, 0.18, P <0.001) increase in birth length and a 0.032 kg (0.022, 0.042, P <0.001) increase in birth weight. Compared to women with inadequate GWG, women who had adequate GWG delivered newborns with a higher mean length and weight: 47.98 ± 2.04 cm compared with 47.40 ± 2.17 cm (P <0.001) and 2.864 ± 0.425 kg compared with 2.764 ± 0.418 kg (P <0.001). Baseline BMI, EWG, and GWG were all associated with birth length and weight.

Conclusions: These results underscore the importance of adequate maternal nutrition both before and during pregnancy as a potentially modifiable factor to improve fetal growth.

Keywords: developing countries; fetal development; gestational weight gain; infant nutrition disorders; low birth weight; malnutrition; nutrition during pregnancy.

FIGURE 1

Consolidated Standards of Reporting Trials (CONSORT) diagram of participant flow. Overall screening, randomization, and obtainment of primary outcome. DRC, Democratic Republic of Congo; MTP, medical termination of pregnancy.

FIGURE 2

Theoretical framework. Framework used to incorporate interventions and variables into statistical models to determine relations between exposures and outcomes. This framework is limited to the variables included in this analysis and does not include other potentially important confounders. GA, gestational age.

FIGURE 3

Adjusted mean differences of infant length by adequacy of gestational weight gain (GWG). Values are mean differences in infant weight (kg) between those with adequate or excessive compared with inadequate GWG after accounting for site, study arm, maternal age, parity, and weight gain from baseline to 12 weeks of gestation using a generalized linear mixed effects model. Weight categories are defined based on BMI: underweight (BMI <18.5), normal weight (BMI 18.5–24.9), and overweight/obese (BMI ≥25). Numbers of women with inadequate GWG by baseline BMI are: underweight (n = 471), normal weight (n = 1020), and overweight (n = 181).

FIGURE 4

Adjusted mean differences of infant weight by adequacy of gestational weight gain (GWG). Values are mean differences in infant length (cm) between those with adequate or excessive compared with inadequate GWG after accounting for site, study arm, maternal age, parity, and weight gain from baseline to 12 weeks of gestation using a linear mixed effects model. Weight categories are defined based on BMI: underweight (BMI <18.5), normal weight (BMI 18.5–24.9), and overweight/obese (BMI ≥25). Numbers of women with inadequate GWG by baseline BMI are: underweight (n = 471), normal weight (n = 1020), and overweight (n = 181).