Contralateral Tubal Ectopic Pregnancy after Ovulation of Another Side Ovary in Spontaneous Cycles: A Case Report and Review of the Literature

Pregnancies in the same side tube after the same side ovary ovulation are more common. We report an unusual case of contralateral tubal ectopic pregnancy after ovulation of another side ovary in spontaneous cycles. A 32-year-old woman underwent laparoscopic left fallopian tube conservative surgery because of left tubal pregnancy two years ago. She returned to our hospital with a positive pregnancy test and lower abdominal pain 28 d after the dominant follicle discharged in the right side ovary detected by transvaginal ultrasound in spontaneous cycles. Transvaginal ultrasonography revealed no intrauterine gestational sac but a left adnexal mass measuring 2.6 cm × 2.5 cm. Videolaparoscopy was performed, and the diagnosis of an ectopic pregnancy in the let fallopian tube was confirmed by pathologic report. Tubal damage is the most important risk factor for tubal ectopic pregnancy. Embryos can be reversely migrated toward fallopian tubes, due to retrograde action of endometrial waves and uterine contractions, that is another necessary reason which contributes to such tubal pregnancy. Total salpingectomy or tubal sterilization is necessary for avoiding repeated tubal ectopic pregnancy.