Levonorgestrel is used worldwide as an emergency oral contraceptive. There have been occasional reports of ectopic pregnancy after oral levonorgestrel use. We present a case of ectopic tubal pregnancy after the use of oral levonorgestrel as an emergency contraceptive in a 37-year-old woman with a history of treatment for Chlamydia trachomatis infection. She conceived after sexual intercourse on menstrual day 14 of the first menstrual cycle following a normal delivery. After salpingectomy for this right tubal pregnancy, her following pregnancy was an ectopic pregnancy in the contralateral tube, which was treated with laparoscopic salpingectomy. Histopathological examination revealed endometriosis. We should be aware of ectopic pregnancy even after emergency contraceptive use, especially in patients with risk factors, such as Chlamydia infection and endometriosis. Because the efficacy of levonorgestrel decreases after ovulation, we should check the stage of the cycle before prescription.
Keywords: ectopic pregnancy; emergency contraception; oral levonorgestrel; progesterone; risk factors.
© 2018 Japan Society of Obstetrics and Gynecology.