Vanetik S, et al. - In previous publications examining the endocrinology of follicular stimulation focusing on luteinizing hormone (LH) levels changes, a sharp drop in LH serum level was observed between cycle days 2 and 6 good prognosis in selected IVF patients. Among 165 consecutive patients treated with a GnRH antagonist-based ovarian stimulation protocol during the year 2015, 33% of the patients exhibited an increase in LH, rather than the expected decrease, after 5 stimulation days. No difference in pregnancy outcome was observed. Mainly “high responders”, or “low responders” had an increase in LH levels during ovarian stimulation. LH rise in mid follicular phase may lead to a sharp LH drop once a GnRH antagonist is provided, and the possible requirement for LH supplementation.  

Researchers here examined if this finding holds true for unselected patients.