Influencing factors and effects of low oocyte retrieval in patients with polycystic ovary syndrome undergoing in-vitro fertilization

Abstract

Objective: To investigate influencing factors and effects of low oocyte retrieval in patients with polycystic ovary syndrome (PCOS) undergoing in-vitro fertilization (IVF).

Methods: In total, 720 patients with PCOS undergoing IVF were enrolled in this retrospective study from January 2017 to December 2022. The oocyte retrieval rate (ORR) was defined as the ratio of the number of oocytes retrieved to the number of follicles ≥ 12 mm in diameter on the trigger day. Using 1 standard deviation from the mean ORR as the boundary value, patients were divided into low and normal ORR groups. Patient characteristics, stimulation protocols, serum hormone levels, oocyte maturity, embryo developmental quality, and pregnancy outcomes of fresh transfer cycles were analysed.

Results: ORR ranged from 0.06 to 2.69, with a mean value of 1.02. Compared with the normal ORR group (ORR ≥ 0.65), patients in the low ORR group (ORR < 0.65) had a higher body mass index; higher antral follicle count (AFC); more days of gonadotrophin stimulation; and lower serum oestradiol (E2) level, lower progesterone level and lower E2 level/follicle (≥12 mm) on the trigger day. Multivariate logistic regression analysis showed AFC [adjusted odds ratio (aOR) 1.05, 95 % confidence interval (CI) 1.0120-1.0940], E2 level/follicle (≥12 mm) (aOR 0.99, 95 % CI 0.9888-0.9972) and progesterone level (aOR 0.41, 95 % CI 0.2402-0.6649) on the trigger day were significantly associated with low ORR. Receiver operator characteristic curve analyses revealed that serum E2 level/follicle (≥12 mm) had an area under the curve of 0.7036 (95 % CI 0.65-0.76; p < 0.01). The cut-off value was 169.2 pg/ml, with sensitivity of 65 % and specificity of 65 %, for predicting low ORR. Low ORR was associated with fewer top-quality embryos and more cycles with no embryos available for transfer. The rates of metaphase II oocytes, top-quality embryos, clinical pregnancy and live birth did not differ between the two groups.

Conclusion: Serum E2 level/follicle (≥12 mm) on the trigger day may be used as a predictive factor for low ORR in patients with PCOS. Low ORR may not affect oocyte and embryo developmental potential under appropriate ovarian stimulation management, but likely increases the risk of no embryos being available for transfer.

Keywords: In-vitro fertilization; Oocyte retrieval; Polycystic ovary syndrome; Pregnancy outcome.