Comparison of Pregnancy Rate and Effective Factors following Fresh and Frozen Embryo Transfer in Women undergoing Assisted Reproductive Techniques (ART)

Embryo cryopreservation is potentially the best method to increase pregnancy rate for the women at risk of OHSS (Ovarian Hyper stimulation Syndrome) and the women at risk of losing ovarian function. With regard to the importance of issue and increasing development in the world regarding to Embryo cryopreservation and following pregnancy, this study was performed with aim to compare pregnancy rate and effective factors following fresh and frozen embryos transfer in women undergoing Assisted Reproductive Techniques (ART) in Milad Infertility Center (Montaserieh).
This cohort study was performed on 200 infertile women who had referred to Mashhad Montaserieh Infertility Center during 2009-2010 for infertility treatment and were candidate for IVF/ICSI. Mature embryos of the patients were used in frozen and fresh groups for embryo transfer to uterus. Data was analyzed by SPSS software (version 11.5) and using Chi-square, independent t, and Kruskal Wallis test. P From 200 infertile women, 80 cases (42%) had pregnancy which 43 (43%) were in fresh embryo group and 37 (37%) in frozen embryo group; the difference was not significant (P=0.38). Infertility causes, number of embryo cells and grading of transferred embryos, delivery complications, method of embryo transfer, number of fetuses obtained from delivery, and endometrial thickness were not statistically different between two groups (P=0.61). But, mean number of transferred embryo was statistically different between fresh embryo group and frozen embryo group (P There was no significant difference between fresh and frozen groups in terms of pregnancy rate and pregnancy complications (P=0.53).