Gestation is a unique physiologic state that carries with it several immunologic consequences and results in changing susceptibility to various diseases. In contrast to the well recognized excess vulnerability of primiparous women to Plasmodium falciparum infection in areas of high malaria transmission, it is not known whether pregnancy is associated with a higher prevalence of helminth infection. In Lambaréné, Gabon, 105 pregnant women were recruited and matched with non-gravid female controls. The prevalence of intestinal helminths was 66% (n=58) in the pregnant participants and 36% (n=32) in the non-pregnant controls (P<0.001). In multivariate analysis the pregnancy status was an independent risk factor for being infected with intestinal helminths (AOR and 95% CI: 3.0 [1.4-5.9]). These data show a previously undescribed susceptibility pattern of pregnant women to intestinal helminth infection in a sub-Saharan African community.