Effectiveness and outcomes of embryo cryopreservation programs in assisted reproductive technologies

Abstract

Background. Embryo cryopreservation is an essential part of ART programs today. In recent years vitrification method is used increasingly widely. Purposes and tasks. To compare the effectiveness of ART programs using vitrified and fresh embryos, as well as different endometrial preparation regimes for frozen\thawed embryo transfer (modified natural cycle (MNC) and the preparatory hormone therapy(PHT)). To analyze the course of pregnancy and perinatal outcomes after vitrified embryo transfer. Materials and methods. We prospectively assessed the ART programs effectiveness and perinatal outcomes in 153 patients (I group), who underwent vitrified embryo transfer in 2011-2013 year. To prepare the endometrium for thawed embryo transfer in 83 patients PHT (Ia subgroup) and MNC in 70 patients (Ib subgroup) were used. Control group consisted of 70 patients, who underwent fresh embryo transfer. Results. The clinical pregnancy rate, birth rate and “take home baby” rate were not significantly different between the I (47,5 %; 30,9 %; 30,9 %) and II (53,0 %; 34,9 %; 32,5 %) groups, and between Ia (48,3 %; 28,4 %; 28,4 %) and IIb (46,6 %; 34,1 %; 34,1 %) subgroups. Complications during pregnancy and delivery, birthweight, length, Apgar score, congenital malformation rate did not differ significantly after vitrified and fresh embryo transfer. Conclusion. Vitrification is an effective method to achieve clinical results, comparable to native cycles. Application of PHT and MNC results in similar clinical outcomes. Transfer Vitrified embryo transfer does not have a negative impact on obstetric and perinatal outcomes when compared with native cycles.