Embryotoxic and growth-retarding effects of malaria on pregnant mice

The effect of the malaria parasite, Plasmodium berghei berghei, on reproductive physiology was studied in mice. Three groups of randomly bred mice consisting of two groups of pregnant females and one group of nonpregnant females were used for the study. Blood-induced infections in mice were used. Endocrinologic evidence was found of an imbalance in endocrine function in the mice with infections. Although there was an elevation in white blood cell counts, the red blood cell counts decreased as the infection progressed. Rectal temperature recordings showed pyrexia and parasitemia in 14% of cases, enough to cause premature delivery in the parasitized pregnant mice. Furthermore, litters from infected mice showed a reduction in birth weight, and malaria parasites were found in the fetal blood and placenta on delivery. In mice, maternal malarial infection, besides reducing the mean birth weight, predisposed to prematurity and adversely affected fetal growth. Placental parasitization could lead to fetal parasitization in utero.