Women who presented with bleeding beyond 20 weeks' gestation and for whom placental abruption, placenta previa, or bleeding due to genital tract lesions was ruled out as the cause of bleeding were categorized as having uterine bleeding of unknown etiology. Information on uterine bleeding was ascertained through two sources: women admitted to the obstetric wards with bleeding as the primary cause for hospital admission, and information on bleeding collected by patient recall during prenatal care visits. Details on the timing and severity of bleeding episodes were not available.