Ratio of oestradiol concentration on the day of human chorionic gonadotrophin administration to mid-luteal oestradiol concentration is predictive of in-vitro fertilization outcome

The role of luteal oestradiol for successful implantation in humans seems t o be permissive rather than obligatory. Few studies have attempted to clari fy the role of early luteal oestradiol in in-vitro fertilization (IVF) outc ome, whether peri-implantation oestradiol is predictive of successful IVF o utcome. We retrospectively analysed 106 women undergoing 106 IVF/embryo tra nsfer cycles. Only the first treatment cycle per patient was analysed. Peak oestradiol denoted the concentration on the day of human chorionic gonadot rophin (HCG) administration. Mid-luteal oestradiol was obtained 3 days afte r embryo transfer (8 days after HCG administration). A total of 44 pregnanc ies were noted (41.51%), There were no differences in age, cycle day 3 foll icle stimulating hormone (FSH), peak oestradiol, number of retrieved oocyte s, number of embryo transfers, and mid-luteal oestradiol between pregnant a nd non-pregnant women. However, the ratio of day of HCG oestradiol to mid-l uteal oestradiol was highly predictive of successful outcome: the ongoing p regnancy rate and implantation rate (sacs with fetal heart beat/embryo tran sfer) were 15.8 and 5.7% respectively if the above ratio exceeded 5.0 (n = 19), compared to 42.1 and 16.3%, and 53.3 and 26.5% if the ratio was betwee n 0.4 and 2.5 (n = 57), and between 2.5 and 5.0 (n = 30) respectively, Our study suggests that the magnitude of decline in oestradiol concentrations a fter oocyte retrieval may be important in predicting IVF success. We postul ate that endometrial integrity may become compromised when a dramatic drop in oestradiol occurs by the mid-luteal period. Whether these women benefit from oestradiol supplementation after oocyte retrieval remains to be invest igated.