Answer--
Hyperreactio luteinalis in normally conceived singleton pregnancy.
Hyperreactio luteinalis is a rare condition in pregnancy that is caused by high -human chorionic gonadotropin (B-hCG) levels or abnormal sensitivity of the B-hCG receptor. It is mostly seen in patients with trophoblastic disease, multiple pregnancy or after fertility treatment. Rarely it can be seen in a singleton spontaneously conceived pregnancy. The maternal ovaries are grossly enlarged with multiple cysts of varying size with prominent stroma. This is benign condition and resolves many times after delivery.