[Impact on outcome of frozen-thawed embryo transfer by reducing numbers of transferred embryos].

Objective: To study the impact on pregnant outcome of reducing the number of embryos transferred from three to two in women at age less than 35 who received frozen-thawed embryo transfer (FET).

Methods: The analysis was performed on 90 FET cycles (77 infertile couples, less than 35 years old) with slow-freezing/rapid-thawing method, including 48 cycles with two embryos transferred and 42 cycles with three embryos transferred. The embryo survival rate, high quality embryo rate, clinical pregnancy rate, implantation rate and multiple pregnancies rate were analyzed.

Results: No significant differences in embryo survival rate (88.9% versus 88.1%), high quality embryo rate (89.6% versus 81.0%), clinical pregnancy rate (37.5% versus 42.9%), implantation rate (26.0% versus 18.3%) and multiple pregnancy rate (38.9% versus 16.7%) were observed between two and three embryos transferred group (all P > 0.05). However, there were 2 triple pregnancies in three embryos transferred group while none in two embryos transferred group.

Conclusion: Reducing the number of high quality embryos transferred from three to two in women at age of less than 35 years old who received FET, could decrease the incidence of triple pregnancy and keep the similar clinical pregnancy rate.