Congenital malaria in a hyperendemic area.

The prevalence of Plasmodium falciparum malaria was evaluated in all near-term pregnant women and their newborns at the Macha Hospital in the Southern Province of Zambia during part of the rainy season, when malaria prevalence is at its peak. Peripheral parasitemia was noted in 19 (29%) of 65 newborns and in 40 (63%) of 63 mothers. All but one of the infected neonates had an infected mother, and 17 of 40 infected mothers gave birth to infected newborns. The parasite densities measured were uniformly low (less than 25,000/cc), and only seven of 19 infected neonates had fever within 48 hours of delivery suggestive of malaria infection. Parasitized newborns had a 469-gm lower average birthweight, but they did not have a higher incidence of prematurity or preterm delivery compared with uninfected newborns. In addition, the Apgar scores of infected and uninfected newborns were not significantly different. There was no correlation between neonatal parasitemia and either the sex of the child or the parity of the mother. Maternal chloroquine prophylaxis did not appear to be effective in preventing infection in the fetus or the gravida, and the emergence of chloroquine resistance may explain, in part, the greater prevalence of congenital malaria in endemic areas in recent years.