The effects of fetal exposure to danazol.

OBJECTIVE: To assess the consequences of exposure to danazol in utero. Additionally, by assessing the risk, to facilitate the counselling of pregnant women inadvertently exposed to danazol in early pregnancy.
DESIGN: Retrospective review of reported case histories.
SUBJECTS: 129 women exposed to danazol during pregnancy were identified from individual case reports, data from the Australian Drug Reactions Advisory Committee and the United States Food and Drug Administration and from the reports of danazol exposure made directly to the manufacturers. MAIN OUTCOME MEASURES: Teratogenic effects of fetal exposure to danazol in relation to dosage and duration of exposure.
RESULTS: Of the 129 reported pregnancies, 12 miscarried and 23 were aborted. Of the 94 completed pregnancies, 37 resulted in the birth of normal males, 34 in non-virilized females and 23 in virilized females. Virilization occurred in a proportion of female fetuses with a pattern of cliteromegaly, fused labia and urogenital sinus formation. Surgery to the genital tract was usually, but not always, required in childhood. The abnormality has not been reported where danazol therapy had been discontinued before the 8th week of pregnancy. Although more common in the higher dosages, virilization was reported in one case with a 200 mg daily dosage.
CONCLUSIONS: Danazol should remain contraindicated in pregnancy and clinicians should give careful contraceptive advice to patients commencing or continuing danazol therapy. Nonetheless it is possible to be cautiously optimistic about the outcome of danazol-exposed pregnancies, particularly if treatment is discontinued before 8 completed weeks gestation.