Spontaneous Late Onset OHSS in Singleton Pregnancy in 2nd Trimester: A Rare Case.

Ovarian hyperstimulation syndrome (OHSS) is a potentially life-threatening complication of pharmacological ovarian stimulation. It is seen in approximately 2 % of all IVF cycles. The prevalence of moderate to severe OHSS ranges from 1 to 10 % in major IVF programs. Severe forms complicate 1 % of IVF cycles and are characterized by massive ovarian enlargement together with a fluid shift into extravascular compartments responsible for the development of ascites, sometimes pleural and/or pericardial effusion, hypovolemia, oliguria, and hydroelectrolytic disorders. In the most marked cases, thromboembolic phenomena may occur as a result of hemoconcentration and coagulation disturbances (Hollemaert et al. [1]). Spontaneous ovarian hyperstimulation (spontaneous OHSS) is extremely rare in naturally conceived pregnancies. OHSS in the absence of exogenous gonadotropins is very rare, and only a few cases have been reported in the literature. Spontaneous OHSS likely to occur at 8–14 weeks of gestation, while iatrogenic OHSS usually occurs earlier at 3–8 weeks of gestation [2]. Human chorionic gonadotropin (hCG) is thought to play a crucial role in the development of the syndrome. Severe forms are indeed restricted to cycles with exogenous hCG to induce ovulation or as luteal phase support or with endogenous pregnancy-derived hCG (Delbaere et al. [3]). Here, we report a rare case of spontaneous 2nd trimester OHSS in 22-year-old primigravida. Patil H. N. Roy R., Assistant Professor Pal R., Assistant Professor Roychowdhury J., Professor & HOD Dept of Obst & Gynae, ESI-PGIMSR & ESIC Medical College & Hospitals, Joka, Kolkata, India