High Burden of Histology-Confirmed Placental Malaria and Associated Adverse Birth Outcomes among Primigravidae in Northwestern Tanzania; A cross-sectional study

Background Malaria remains a major public health problem in Sub-Saharan Africa, including Tanzania, contributing significantly to maternal and neonatal morbidity and mortality. Placental malaria (PM) is linked to adverse fetal outcomes such as preterm birth, low birth weight, small-for-gestational-age infants, congenital malaria, and intrauterine death. Primigravidae are particularly vulnerable due to limited malaria-specific immunity and socio-economic barriers. This study aimed to determine the prevalence of placental malaria, fetal outcomes, and associated factors among primigravidae women delivering at Sengerema Designated District Hospital (DDH), Mwanza, Tanzania. Methods A hospital-based cross-sectional study enrolled 422 primigravidae women from October 2024 to April 2025. Structured questionnaires and antennal care (ANC) card reviews captured socio-demographic, obstetric, and medical information. Maternal peripheral, cord, and placental blood were screened for malaria using rapid diagnostic tests (MRDT), microscopy and placental histology. Neonatal outcomes recorded included birth weight, gestational age, survival, and growth for gestational age. Results The study showed histologically confirmed PM prevalence of 39.8% (95% CI: 35.1–44.5), and 23.7% (95% CI: 19.6–27.8) by microscopy. The prevalence for maternal peripheral malaria and congenital malaria by microscopy was found to be 19.7% (95% CI: 15.9–23.5 and 6.9% (95% CI: 4.5–9.3) respectively. Significant predictors of PM included fewer than four ANC visits (aOR = 1.75, p = 0.04), and moderate anemia (aOR = 1.84, p = 0.04). PM was significantly associated with low birth weight (p = 0.01), preterm birth (p = 0.001), and small-for-gestational-age neonates (p = 0.048). Conclusion Placental malaria is highly prevalent among primigravidae women attending Sengerema DDH. Early ANC attendance, supervised IPTp uptake, and improved diagnostic detection are critical to reducing malaria-related maternal and neonatal complications.