Supplementary feeding and infection control in pregnant adolescents—A secondary analysis of a randomized trial among malnourished women in Sierra Leone

Undernutrition during pregnancy in adolescence confers a high risk of maternal morbidity and adverse birth outcomes, particularly in low‐resource settings. In a secondary analysis, we hypothesized that younger undernourished pregnant adolescents (<18 years) would benefit more than undernourished pregnant adults (>20 years) from the intervention of supplementary food and anti‐infective treatments. The original trial in Sierra Leone enrolled 236 younger adolescents (<18 years), 454 older adolescents (aged 18–19 years), and 741 adults (≥20 years), all with a mid‐upper arm circumference ≤23 cm. Younger adolescents had lower final fundal height as well as smaller newborns (−0.3 kg; 95% confidence interval [CI], −0.3, −0.2; p < 0.001) and shorter newborns (−1.1 cm; 95% CI, −1.5, −0.7; p < 0.001) than adults. The intervention's effect varied significantly between maternal age groups: adults benefited more than younger adolescents with respect to newborn birth weight (difference in difference, 166 g; 95% CI, 26, 306; interaction p = 0.02), birth length (difference in difference, 7.4 mm; 95% CI, 0.1, 14.8; interaction p = 0.047), and risk for low birth weight (<2.5 kg) (interaction p = 0.019). The differences in response persisted despite adjustments for maternal anthropometry, the number of prior pregnancies, and human immunodeficiency virus status. Older adolescents similarly benefited more than younger adolescents, though differences did not reach statistical significance. In conclusion, newborns born to younger adolescent mothers had worse outcomes than those born to adult mothers, and adults and their newborns benefited more from the intervention than younger adolescents.