Time to revolutionize the triggering of ovulation

Methods used for ovarian stimulation constantly change with advances in gonadotrophin therapy. In this Commentary, an appeal is made for more attention to the use of LH for the induction of ovulation. Its typical characteristics during the LH surge are finely balanced to induce normal ovulation and luteinization. It does not induce ovarian hyperstimulation, for example. The recent commercial availability of recombinant LH (LHr) offers a chance of escaping from the use of urinary human chorionic gonadotrophin (HCG) and its varied forms such as those with a shorter half-life. It should also avoid the weakly effective bursts of FSH and LH and weak luteal phases released associated with the use of gonadotrophin-releasing hormone agonists. Currently, large dosages of LHr are needed to match the endocrine events typical of inducing ovulation by the endogenous LH surge. In the interests of patients' safety and improved forms of luteal phase endocrinology, research should be devoted to improving the properties of rLH to make it induce surges similar to endogenous discharges. This would replace the current use of HCG to induce ovulation, with its attendant risks of ovarian hyperstimulation and luteal phase anomalies.