Autologous endometrial coculture biopsy: is timing everything?

Objective To determine whether endometrial biopsy timing affects implantation rates and pregnancy outcomes in patients undergoing in vitro fertilization (IVF) with autologous endometrial coculture (AECC). Design Retrospective cohort study. Setting Academic medical center. Patient(s) All patients with a history of at least one failed IVF cycle who underwent an IVF-AECC cycle at our center from May 2004 to November 2013 were included. Intervention(s) Patients underwent luteal-phase endometrial biopsy in preparation for IVF. Biopsy samples were used for IVF in either the subsequent menstrual cycle or a future cycle. Embryos were cultured in AECC media and transferred on day 3. Main Outcome Measure(s) A total of 2,533 cycles of 1,719 patients who underwent an IVF-AECC cycle were identified. Cycles were stratified by endometrial biopsy timing. Clinical outcomes, including implantation, pregnancy, and live birth rates, were analyzed and compared between the two groups. Result(s) A total of 1,416 coculture biopsies were performed in the menstrual cycle before IVF and 1,117 were performed more than one cycle before IVF. The two groups were similar in age, body mass index, number of mature oocytes retrieved, and best embryo grade. There were no significant differences in implantation, clinical pregnancy, or live birth rates, with adjusted relative risks of 1.02 (95% confidence interval [CI] 0.92–1.13), 1.02 (95% CI 0.91–1.14), and 0.99 (95% CI 0.86–1.16), respectively. Conclusion(s) Coculture biopsy in the cycle preceding IVF does not increase implantation, clinical pregnancy, or live birth rates compared with biopsies performed more than one cycle before IVF. Previously demonstrated improvements in embryo quality and pregnancy outcomes in patients undergoing IVF with AECC are probably not attributable to biopsy-induced endometrial injury.