OBJECTIVETo compare the clinical outcomes of in vitro fertilization and embryo transfer (IVF-ET) among patients in different conditions receiving luteinizing hormone supplementation in GnRH-agonist long protocol.

METHODSBetween June, 2010 and December, 2015, 671 IVF-ET cycles with GnRH-agonist long protocol were performed at our center. These cycles were divided into group A with FSH only and group B with FSH and recombinant luteinizing hormone (r-LH) supplementation, and each group was divided into 4 subgroups according to age (<35 or ≥35) and the LH level on the initial day (<1.0 U/L or ≥1.0 U/L). The effects of LH supplementation on the clinical pregnancy rate and implantation rate were compared among different subgroups.

RESULTSNo statistical significances were found between groups A and B in age, body mass index (BMI), basal FSH, basal LH, basal E2, Gn dosage, Gn day, LH on HCG day, E2 on HCG day, P on HCG day, number of oocytes, fertilization rate, available embryo rate or good quality embryo rate per oocyte, but the endometrium thickness on HCG day differed significantly between the two groups. In women below 35 years of age with a LH level on HCG day over 1.0 U/L, r-LH supplementation resulted in a clinical pregnancy rate of 60%, significantly lower than the rate of 79.55% in women without r-LH supplementation (P<0.05). In women over 35 years with a LH level below 1.0 U/L, r-LH supplementation resulted in an implantation rate of 44.74%, as compared with 24.74% in women without r-LH supplementation (P<0.05).

CONCLUSIONIn the long protocol, LH supplementation does not improve the oocyte number, fertilization rate, or good quality embryo per oocyte, and does not bring benefits to women below 35 years with a low LH level (<1.0 U/L) or those over 35 years with normal LH level (≥1.0 U/L) after GnRH-agonist administration. But for women over 35 years with low LH levels, r-LH supplementation may improve the clinical pregnancy rate and implantation rate of IVF-ET cycles.