Schistosomiasis control programmes are generally based on mass distribution of praziquantel (PZQ). This approach has been further strengthened by studies that demonstrated reduction in schistosomiasis-related morbidity following regular use of PZQ. Many women were excluded from this therapy when pregnant. Since a high degree of parity is achieved in many schistosomiasis-endemic regions, excluded women often miss treatment and consequently the beneficial effect of this therapy. This study investigated the effect of PZQ therapy on pregnancy in the Gezira region of Sudan. As part of the Blue Nile Health Project, more than 320,000 individuals received annual treatment with PZQ from 1980 to 1990. The present study reviewed the treatment records of all women between 1990 and 1995 in four villages. Eighty-eight of 637 women interviewed had received PZQ during their pregnancy. The outcome and the effect of PZQ therapy on their offspring were compared with a group of 549 women who had not received the drug during pregnancy. There were no significant differences between the two groups in the rate of abortion or preterm deliveries. No congenital abnormalities were noted by clinical examination in any of the babies born to either group. This retrospective study suggested that PZQ therapy is safe during pregnancy.

In a prospective study carried out in New Halfa Teaching Hospital, in eastern Sudan, between June 2001 and April 2003, 25 pregnant Sudanese women with schistosomiasis mansoni were each treated with a single oral dose of praziquantel (PZQ), at 40 mg/kg. The drug was given to six (24%), 12 (48%) and seven (28%) of the women during the first, second and third trimesters of their pregnancies, respectively. The patients were followed-up until delivery and their babies were followed-up until they were 1 year old. Although one patient, who received PZQ after 10 weeks of gestation, aborted (3 weeks post-treatment), this frequency of abortion is similar to that seen in the local community. None of the treated women died, and there were no stillbirths or congenital abnormalities in the newborn babies. Although this is a small trial, it appears that PZQ is a safe drug to use against schistosomiasis mansoni, even during the first trimester of pregnancy.