Serum Kisspeptin levels in unexplained infertility, polycystic ovary syndrome, and male factor infertility.

Kisspeptin (KP), a hypothalamic peptide, is known as an important marker for neuroendocrine regulation during the human reproduction process. The unexplained infertility (UI) group comprised 30 patients, polycystic ovary syndrome (PCOS) group comprised 29 patients and the male factor infertility (MFI) group comprised 27 patients. An observational cohort study was conducted. The basic characteristics of the study population, BMI, and serum FSH, LH, E2, AMH, KP, TSH, and PRL levels and antral follicle count (AFC) on the 3rd menstruation day were evaluated. The mean KP level was 281.98 ± 73.9 ng/ml in the UI group, 525.49 ± 164.17 ng/ml in the PCOS group, and 354.313 ± 111.38 ng/ml in the MFI group (p < .001). KP levels were significantly higher in the PCOS group than in the UI and MFI groups (p < .001 for both). AUC was 83% (95% CI: 73%-93%), with 375.15 (pg/ml) as the cutoff value in the PCOS group with 83% sensitivity and 79% specificity. UI may be treated by KP injection therapies and higher levels of KP may be a reliable marker for AFC and diagnosis of PCOS. Clinical Trials registration number: NCT03018314.