Spontaneous Ovarian Hyperstimulation Syndrome in a hypothyroid patient

The ovarian hyperstimulation syndrome most often occurs as a complication of ovarian-stimulation treatments for in vitro fertilization in infertility. The clinical picture may vary from abdominal distension and discomfort to potentially life-threatening, massive ovarian enlargement and capillary leak with fluid sequestration in a third space.
The association between early pubertal development and primary hypothyroidism was first described over 40 years ago. Ovarian stimulation in the hypothyroid child may result in oestrogen production, breast development, endometrial proliferation, and vaginal bleeding. It is likely that raised TSH concentrations bind and stimulate the FSH receptor, although a similar overlap phenomenon might occur at the level of the pituitary, with enhanced TRH production stimulating the GnRH receptor with subsequent ovarian enlargement. The cystic ovarian enlargement resolves with thyroid hormone replacement.
A hyperstimulation phenomenon in patients with an abnormal FSH receptor has been described.
Imaging findings in OHSS include bilateral symmetric enlargement of ovaries with multiple cysts, giving the classic wheel-spoke appearance. This can be associated with ascitis and pleural effusion which is due to capillary leak.
To avoid unnecessary laparotomy, we emphasize the importance of careful diagnosis to differentiate spontaneous OHSS from ovarian cystic neoplasms.