Malaria in the First Trimester of Pregnancy and Fetal Growth: Results from a Beninese Preconceptional Cohort

Background: Malaria in early pregnancy occurs at a time when the placenta is developing, with possible consequences for placental function and fetal growth. We assessed the association between first trimester malaria and fetal growth documented through repeated ultrasound scans. Methods: The RECIPAL preconceptional cohort included 411 Beninese pregnant women followed from 7 weeks' gestation (wg) until delivery. Among them, 218 had 4 scans for fetal monitoring at 16, 22, 28, and 34 wg. Multivariate seemingly unrelated regression models were used to assess association of microscopic malaria in the first trimester (<15 wg) with abdominal circumference, head circumference, biparietal diameter, and femur length throughout pregnancy. Results: Of 39% (86/218) of women with at least 1 microscopic malarial infection during pregnancy, 52.3% (45/86) were infected in the first trimester. Most women (88.5%) were multiparous. There was no association between adjusted z-scores for fetal growth parameters and first trimester malaria. Parity, newborn sex, socioeconomic level, and maternal body mass index significantly influenced fetal growth. Conclusions: In a context where malaria infections in pregnancy are well detected and treated, their adverse effect on fetal growth may be limited. Our results argue in favor of preventing and treating infections as early as the first trimester.