A 41-Year-Old Woman with Spontaneous Hemoperitoneum in Pregnancy at 28 Weeks.

BACKGROUND Spontaneous hemoperitoneum in pregnancy (SHiP), defined as nontraumatic, acute intra-abdominal bleeding during pregnancy or the postpartum period, is a serious life-threatening complication to mother and child. Endometriosis is a major risk factor for SHiP. This study presents the case of a 41-year-old woman with adenomyosis who developed hemoperitoneum due to endometriosis at 28 weeks of pregnancy. CASE REPORT The patient was a 41-year-old woman (gravida 1, para 0) who conceived via artificial insemination. She had diffuse adenomyosis in the posterior uterine wall and was admitted to our hospital at 12 weeks of gestation with persistent lower abdominal pain. She had started treatment with hydroxyprogesterone caproate to reduce the focal inflammation of adenomyosis. At 28 weeks of gestation, she developed severe lower abdominal pain, and ultrasonography revealed prolonged fetal heart rate deceleration. An emergency cesarean delivery was performed, and a 907 g female infant with an Apgar score of 2/3 was delivered. Umbilical artery blood pH was 7.15. Bleeding from the veins surrounding an endometriotic lesion on the posterior wall of the uterus was observed, and SHiP was diagnosed. CONCLUSIONS Pregnancies complicated by endometriosis or adenomyosis require perinatal management, considering the possibility of SHiP complication. If acute abdominal pain and fetal heart rate deceleration occur during pregnancy, a search for intra-abdominal bleeding should be performed and emergent open hemostasis or cesarean delivery should be considered.