Background. The role of oxidative stress factors and regulators of vascular tone and angiogenesis in the pathogenesis of a «poor» response to ovarian stimulation is still being studied. Objective. To study the biochemical and regulatory factors in blood serum and follicular fluid of patients with a «poor» ovarian response, in comparison with similar indicators in women with a normal response to controlled ovarian stimulation. Material and methods. The study involved 56 patients included in the IVF program and divided into two groups depending on the ovarian response to controlled ovarian stimulation: the main group (with a «poor» response to stimulation) and the comparison group (with a normal ovarian response). The content of biochemical and soluble regulatory factors in venous blood serum and follicular fluid samples (with and without oocyte-cumulus complex) on the day of transvaginal puncture was assessed. Results. Patients with a «poor» ovarian response showed an increase in the level of total protein, albumin, creatinine, cholesterol, total antioxidant capacity, endogenous nitrite and the soluble receptor for vascular endothelial growth factor (VEGFR-2) in blood serum on the day of transvaginal puncture. In the follicular fluid of patients with a «poor» ovarian response, containing an oocyte-cumulus complex, the urea content was higher, and the content of bilirubin, uric acid and lactate dehydrogenase was lower than in similar samples of follicular fluid of patients with a normal response to controlled ovarian stimulation. Additionally, in the follicular fluid samples from patients in the main group who did not contain an oocyte-cumulus complex, there was a decrease in VEGF and its receptor levels, as well as an increase in endogenous nitrite levels, compared to women with a normal ovarian response. Conclusions. Controlled ovarian stimulation in patients with a «poor» ovarian response is accompanied by nitrooxidative stress, which is confirmed by an increase in the content of endogenous NO2 in both blood serum on the day of follicle puncture and in follicular fluid. The absence of an oocyte-cumulus complex in the preovulatory follicle with a «poor» response to CBS is associated with a violation of vascularization processes, established on the basis of a decrease in pro- and antiangiogenic factors (VEGF-A and sVEGFR-2).
BASHMAKOVA et al. (Sun,) studied this question.