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Rate of blastocyst development from excess embryos remaining in culture after day 3 embryo transfer.

OBJECTIVE
To assess the rate of blastocyst development (BDR) from embryos remaining in culture after day-3 embryo transfer (ET), and its relationship to cause of infertility.


STUDY DESIGN
Retrospective cohort study in tertiary-care IVF Center. Blastocyst development rate (BDR) after day-3 ET was assessed in 126 women who underwent either conventional IVF or ICSI.


RESULTS
Mean age, early follicular FSH levels, number of 2PN zygotes, number of excess embryos, and number of ET were similar between patients that underwent IVF and ICSI. Overall, 20% of extra embryos from conventional IVF patients developed into blastocysts compared to 14% of embryos obtained from ICSI. Cause of infertility did not affect BDR, even in patients who required ICSI due to male factors.


CONCLUSIONS
Low rates of blastocyst development from excess embryos are similar between IVF and ICSI patients. Only 15 to 25% of excess embryos left in culture develop into blastocysts, regardless of cause of infertility. Physicians and patients can use this information to adjust both AR treatment protocols and patient expectations.