Causal effects on low 5-minute Apgar and stillbirths in an investigation of malaria and maternal-fetal health: a perinatal surveillance study in the Brazilian Amazon

The elimination of malaria in Brazil presents several challenges, including the control of Plasmodium falciparum outbreaks and the hidden burden of Plasmodium vivax in pregnancy. Maternal malaria and fetal health outcomes were investigated with a perinatal surveillance study in the municipality of Cruzeiro do Sul, state of Acre, Brazilian Amazon. While Brazil is on its way to eliminating malaria, the population still faces major structural problems, including low living standards. Here, malaria infections in pregnant women were observed to have indirect effects on fetal outcomes, contributing to low Apgar at 5 min and stillbirth. Finally, the usefulness of employing multiple statistical analysis methods to validate consistent trends is vital to securing public health intervention designs. 

From November 2018 to October 2019, pregnant women at 22 weeks or postpartum, who gave birth at the reference maternity hospital (Hospital da Mulher e da Criança de Juruá), were recruited to participate in a malaria surveillance study. Clinical information was obtained from a questionnaire and abstracted from medical reports. Hemoglobin level and presence of malaria parasites were tested by hematology counter and light microscopy, respectively. Low 5-minute Apgar score and stillbirth were analyzed in terms of clinical data and epidemiological risk factors for maternal malaria infection using an additive and independent effects model and a causal model with control for confounding factors and use of mediation. 202 (7.2%; N = 2807) women had malaria during pregnancy. Almost half of malaria infections during pregnancy (n = 94) were P. falciparum. A total of 27 women (1.03%; N = 2632) had perinatal malaria (19 P. vivax and 8 P. falciparum). Perinatal anemia was demonstrated in 1144 women (41.2%; N = 2779) and low birth weight occurred in 212 newborns (3.1%; N = 2807). A total of 75 newborns (2.7%; N = 2807) had low (<7) Apgar scores at 5 minutes, and stillbirth occurred in 23 cases (30.7%; n = 75). Low birth weight resulted in a 7.1 higher odds of low Apgar at 5 min (OR = 7.05, 95% CI 3.86-12.88, p < 0.001) modulated by living in rural areas, malaria during pregnancy , perinatal malaria and perinatal anemia. Stillbirth was associated with perinatal anemia (OR = 2.56, 95% CI 1.02-6.42, p = 0.0444) modulated by living in rural conditions, falciparum malaria during pregnancy, perinatal malaria and perinatal fever.

Project details

Surveillance

Feb 2022

Brazil