HMG versus recombinant FSH plus recombinant LH in ovarian stimulation for IVF: does the source of LH preparation matter?

Studies on the role of LH supplementation in patients undergoing assisted reproductive technique use different sources of LH bioactivity-containing preparations, daily doses and modes of administration. This review aims to critically present the available evidence comparing the effect of the two commercially available LH preparations (human menopausal gonadotrophin [HMG] and recombinant FSH + recombinant LH) with different sources of intrinsic LH bioactivity (HCG versus LH, respectively) on ovarian stimulation characteristics and IVF cycle outcomes. A literature review was conducted for all relevant articles reporting on IVF and intracytoplasmic sperm injection treatment outcome after ovarian stimulation using HMG or recombinant FSH plus recombinant LH. The available studies are mostly observational, using different daily doses and modes of administration. No statistically significant differences were observed in ovarian stimulation variables and clinical pregnancy and live birth rates when HMG was compared with recombinant FSH + recombinant LH. Moreover, combined analysis of all the available prospective and retrospective studies produced no firm conclusions in favour of either source of LH bioactivity. Further large randomized controlled studies are needed to investigate the effect of the LH source on IVF outcome and to identify patients who are most likely to benefit from the addition of LH bioactivity supplementation.