Kisspeptin and embryo implantation after ICSI.

A cross-sectional study was carried out at the Australian Concept Infertility Medical Centre from June 2014 to June 2015 to relate serum kisspeptin levels on human chorionic gonadotrophin (HCG) day with pregnancy outcome after intracytoplasmic sperm injection (ICSI). A total of 176 women aged 20 to 42 years, with regular menstrual cycles, normal thyroid function and prolactin levels selected for ICSI were included in the study. Patients with uterine fibroids, metabolic disorders, short agonist and antagonist protocol were excluded. Long protocol for down-regulation of ovaries was observed and kisspeptin levels were estimated on HCG day. Results were categorized into groups: Group A, non-pregnant with β-HCG <25 mIU/ml; and Group B, clinical pregnancy with β-HCG >25 mIU/ml and cardiac activity on transvaginal scan. Kisspeptin levels were significantly higher in Group B versus Group A (P < 0.001), independently associated with positive pregnancy (r = 0.388; P < 0.001), but just borderline with endometrial thickness (r = 0.294; P = 0.05). The area under the curve was highest for kisspeptin, 0.784 (95% CI, 0.681 to 0.886) for positive pregnancy, which indicated that kisspeptin measured on HCG day can be used as a marker for success of treatment in women after ICSI.