One of the major problems of success in infertility treatment could depend on the understanding how the potential factors may affect the conception. The aim of this study was to evaluate present understanding of such factors or hormonal causes that may induce infertility. We studied the interactions between the two menstrual cycle hormones i.e., cortisol (COR) and prolactin (PRL), along with the ultrasonographic ovulation parameters in a group of N = 205 women with diagnosed infertility. The control group consisted of N = 100 women with confirmed fertility. In both groups, follicle-stimulating hormone (FSH), luteinizing hormone (LH), anti-Müllerian hormone (AMH), thyroid stimulating hormone (TSH), PRL, COR were examined on the third day of the cycle, and estradiol (E2), progesterone (P), and COR were examined during ovulation and 7-days afterwards. In the infertile group, higher levels of PRL and COR were observed than that of in the control group. Cortisol levels at all phases of the menstrual cycle and PRL negatively correlated with E2 secretion during and after ovulation, thus contributed to the attenuation of the ovulatory LH surge. Infertile women who conceived presented with higher levels of E2 during and after ovulation, higher P after ovulation, and thicker endometrium than that of the women who failed to conceive. In conclusion, elevated secretion of COR and PRL in infertile women impairs the menstrual cycle by decreasing the pre-ovulatory LH peak and E2 and postovulatory E2 levels that affect the endometrial growth, and consequently reduce the chances to conceive.
Keywords: cortisol; hypothalamic–pituitary–gonadal axis; infertility; menstrual disorders; prolactin.