Embryo incubation and selection in a time-lapse monitoring system improves pregnancy outcome compared with a standard incubator: a retrospective cohort study.

OBJECTIVE: To quantify the effect on reproductive outcome of culturing and selecting embryos using a novel time-lapse monitoring system (TMS).

DESIGN: Retrospective observational cohort study.

SETTING: University-affiliated private center.

PATIENT(S): Donation and autologous intracytoplasmic sperm injection (ICSI) cycles from ten IVF clinics using similar procedures, cultured in TMS (n = 1,390) or in a standard incubator (SI; n = 5,915).

INTERVENTION(S): None.

MAIN OUTCOME MEASURE(S): Clinical pregnancy rate confirmed by ultrasound in week 7.

RESULT(S): A logistic regression analysis, which included all significant confounding factors, was used to evaluate the effect of culturing and selecting embryos with the use of TMS. Comparing clinical pregnancy rates per oocyte retrieval with TMS and SI treatments gave a crude effect of odds ratio [OR] 1.190 (95% confidence interval [CI] 1.058-1.337). Oocyte source, maternal age, day of transfer, and number of retrieved oocytes were identified as significant confounding factors. After accounting for confounding factors, the effect of TMS culture was OR 1.201 (95% CI 1.059-1.363). Limiting analysis to treatments with embryo transfer and including number of transferred embryos as a confounding factor likewise gave a significant effect of TMS with OR 1.157 (95% CI 1.018-1.315).

CONCLUSION(S): Analysis of retrospective data indicated that culturing and selecting embryos by TMS significantly improved the relative probability of clinical pregnancy (+20.1% per oocyte retrieval, +15.7% per embryo transfer). The elevated clinical pregnancy rate was attributed to a combination of stable culture conditions and the use of morphokinetic parameters for embryo selection.