Attachment of a trophoblastic spheroid onto endometrial epithelial cells predicts cumulative live birth in women aged 35 and older

To evaluate the attachment rate of a human embryonic stem cell-derived trophoblastic spheroid onto endometrial epithelial cells in predicting the cumulative live birth rate of an in vitro fertilization (IVF) cycle.A prospective observational study.University hospital and research laboratory.A total of 240 infertile women from 2017-2021.Infertile women with regular cycles attending for IVF were recruited. An endometrial aspirate was collected from a natural cycle 1 month before IVF to determine the BAP-EB attachment rate.Cumulative live birth rates from a stimulated cycle and its derived frozen embryo transfer cycles within 6 months of ovarian stimulation were obtained.The BAP-EB attachment rate in women who attained a cumulative live birth was similar to that in those who did not. When women were stratified by age into <35 years and ≥35 years, the BAP-EB attachment rate was significantly higher only in women aged ≥35 years having a live birth when compared with those in the same age group without a live birth. Receiver operating characteristic curve analysis of BAP-EB attachment rate in predicting cumulative live birth showed the areas under the curve of 0.559 (95% confidence interval [CI], 0.479-0.639), 0.448 (95% CI, 0.310-0.585), and 0.613 (95% CI, 0.517-0.710) for all ages, an age of <35 years, and an age of ≥35 years, respectively.The BAP-EB attachment rate offers only a very modest prediction of the cumulative live birth rate in women aged ≥35 years undergoing IVF.NCT02713854 (https://clinicaltrials.gov/ct2/show/NCT02713854; Date of registration, March 21, 2016; date of enrollment of the first subject, August 1, 2017).