Early pregnancy loss is significantly higher after day 3 single embryo transfer than after day 5 single blastocyst transfer in GnRH antagonist stimulated IVF cycles.

The current study aimed to investigate whether single day-3 embryo transfer (SET) results in higher early pregnancy loss (EPL) than single blastocyst transfer (SBET). A total of 896 patients underwent 1103 IVF cycles with a gonadotrophin-releasing hormone (GnRH) antagonist protocol. In 603 cycles (D3 group) a single embryo on day 3 of the embryo culture was transferred, whereas in the remaining 500 cycles a single blastocyst was transferred on day 5 (D5 group).