(569) Associations between Malaria in Pregnancy and Variation in Fetal Growth Restriction by Fetal Growth Curves

Objective: Intergrowth-21(IG21) and World Health Organization (WHO) growth curves are designed to establish international standards for fetal growth. However, much of these data were not collected from malaria endemic countries, where malaria in pregnancy is a major risk factor for fetal growth restriction (FGR) and small-for-gestational age (SGA). We assessed the relationship between malaria and FGR using these two growth curves.

Study Design: Data were collected from 751 women with singleton pregnancies enrolled between 12-20 weeks gestational age in a malaria chemoprevention trial. Fetal biometry data at 32 weeks was used to calculate estimated fetal weight (EFW) and percentiles according to IG21 and WHO fetal growth curves. FGR and SGA were defined as EFW and birthweight < 10^th percentile for gestational age, respectively. Malaria status was assessed in two ways: (1) clinical malaria (fever and microscopic parasitemia) and (2) placental malaria (parasites and/or hemozoin pigment by histopathology). Multiple logistic regression was used to estimate associations between malaria and FGR and SGA risk, adjusted for gravidity and bednet use.

Results: Among women with no evidence of malaria during pregnancy (n=87), the risk of FGR varied between growth standards (IG21=13.8%, WHO=22.9%). 97 women (12.9%) were diagnosed with at least 1 episode of clinical malaria and 17 (2.3%) had 2 or more episodes. 238 women (31.7%) had evidence of placental malaria, with a majority of these only having pigment detected. Neither clinical nor placental malaria were associated with increased risk of FGR at 32 weeks by either growth curve, but was associated with increased risk of SGA, though no associations reached statistical significance (See Table).

Conclusion: In our study, FGR prevalence varied between IG21 and WHO standards, warranting future research to determine which metric should be used in malaria-endemic settings. Malaria was a predictor of risk of SGA, but not FGR at 32 weeks, although analyses were limited by low sample size. Our results suggest that malaria may impact fetal growth towards the end of pregnancy.