ABSTRACT

Many studies have reported on the prevalence and severity of malaria in pregnant women. These consistently demonstrated a higher P. falciparum prevalence in primigravidae than multigravidae. The weighted relative risk for this increased prevalence is 1.9 (95% CI 1.8-2.0). In this review the predilection to malaria in first pregnancies is considered in relation to the concept of parity specific immunity. Most observations relate primarily to P. falciparum, although there is now evidence that P. vivax is also more common in primigravidae. A model for parity specific immunity is presented based on that of Ross which explained reduced prevalence due to an increased recovery rate from infection. The model is used to derive malaria prevalence patterns in areas of low incidence and seems to adequately describe the dynamics of parity specific differences in malaria risk in women not taking chemoprophylaxis. Gestational and postnatal changes in malaria prevalence and anemia patterns are also reviewed. Primigravidae living under high transmission intensity are at least at 1.5 times increased risk of severe anemia (<8 gms/dl) compared to multigravidae.