Özçakir, HTLevi, RTavmergen, EGöker, ENT2024-07-182024-07-181447-0756http://akademikarsiv.cbu.edu.tr:4000/handle/123456789/7261WILEYArticleAim: To examine the effect of premature luteinization on the outcomes in long gonadotropin-releasing hormone agonist cycles. Methods: Two-hundred and forty-eight patients who had undergone assisted reproductive technology for infertility treatment between 2001 and 2002 were enrolled into the study. The patients were separated into two groups according to P/E2 ratios on human chorionic gonadotropin administration day. Group A consisted of the patients whose P/E2 ratio was 1 (n = 116) and Group B consisted of the patients with premature luteinization of which P/E2 ratio was > 1 (n = 132). The P/E2 ratio calculation was performed as follows: P (in ng/ mL) xdagger1,000/E2 (in pg/mL). The primary outcome measures included oocyte quality, fertilization rates and clinical pregnancy rates. Results: The mean number of mature oocytes retrieved in the groups were 9.5 +/- 4.8 and 6.4 +/- 3.6, respectively, and the difference was statistically significant (P < 0.05). Although the difference between the fertilization rates in Group A and Group B was not statistically significant (P > 0.05), the clinical pregnancy rates seemed to be affected adversely in the Group B patients with premature luteinization (41.4% versus 28%, respectively; P < 0.05). Conclusion: Premature luteinization, defined as P/E2 > I on human chorionic gonadotropin administration day, in long gonadotropin-releasing hormone agonist cycles seems to adversely affect clinical outcome.IN-VITRO FERTILIZATION