腹腔鏡下卵巣部分切除術により妊娠継続を可能とし生児を得た単一胚移植後の正所異所同時妊娠の一例

抄録

　The incidence of heterotopic pregnancy during natural conception is approximately 1 in 15,000 to 30,000 pregnancies (0.003%). This incidence increases to an estimated 1 in 670 pregnancies for those achieved through assisted reproductive technology, albeit with some variability in the literature. No precise statistics are available regarding the frequency of simultaneous intrauterine and ectopic pregnancies occurring during single embryo transfer and natural conception. However, international reports, including our own, have documented only seven such cases, which supports their extreme rarity. Our patient was a 31-year-old gravida 4 para 0 woman who underwent single embryo transfer using in vitro fertilization at another hospital. A fetal sac was confirmed in the uterus at 5 weeks and 1 day of gestation. At 6 weeks and 0 days of gestation, the patient presented to our hospital with worsening lower abdominal pain since 3 days previously. Diagnosing the condition was challenging; however, multiple transvaginal ultrasound examinations and detailed medical interviews suggested a heterotopic pregnancy. Using magnetic resonance imaging (MRI), we developed a precise surgical plan and performed laparoscopic partial ovarian resection. By preserving the corpus luteum in the left ovary and removing only the ectopic pregnancy tissue, the intrauterine pregnancy was sustained and resulted in a successful live birth. Although heterotopic pregnancy is rare in cases of single embryo transfer, it should be considered during examination. MRI is effective for both diagnostic assistance and surgical planning, and its use should be considered when necessary, even during the first trimester of pregnancy.