Serum complement assay (CH50) was carried out in urban low-income women belonging to the following groups: (i) non-pregnant and non-lactating women; (ii) pregnant women in different periods of gestation; (iii) women suffering from pregnancy-induced hypertension. Serum CH50 titers showed significant increase in the second and third trimester pregnancies as compared to non-pregnant, non-lactating women. There were no differences in CH50 levels between women suffering from pregnancy-induced hypertension and those with normal pregnancy of comparable period of gestation. Nutritional status did not seem to have any influence on complement titers.