RESUMEN

INTRODUCTION: Ovarian hyperstimulation syndrome (OHSS) is extremely rare in spontaneous pregnancies. Spontaneous OHSS can result from glycoprotein hormones stimulating follicle-stimulating hormone receptors (FSHR). PRESENTATION OF CASE: We report a twin pregnancy in which ovarian torsion and hemoperitoneum complicating OHSS were treated with left adnexectomy and aspiration. The only trigger for spontaneous OHSS in this case was high levels of chorionic gonadotropin hormone. DISCUSSION: Multiple pregnancy, gestational trophoblastic disease, primary hypothyroidism, thyroid-stimulating hormone/gonadotropin-secreting adenomas, and mutations of the FSHR gene may trigger spontaneous OHSS. CONCLUSION: Spontaneous OHSS should be included in the differential diagnosis of acute abdomen in pregnant women; if spontaneous OHSS is diagnosed, the etiology should be determined in order to focus the treatment and avoid future complications.