Pregnancy outcomes following in vitro fertilization using fresh or frozen embryo transfer

The aim of this study was to investigate the pregnancy outcomes in women undergoing IVF using fresh and/or frozen embryo transfer.

In this retrospective patient record study, we reviewed 2,872 infertile women's files, who were candidates for IVF. The patients were classified into two groups, including those who underwent fresh embryo transfer (n=1628) and/or frozen embryo transfer (FET) (n=1244).

Fertility was achieved in 313 (19.23%) and 356 (28.62%) patients, who underwent fresh ET and FET, respectively. The rates of clinical pregnancy, ongoing pregnancy, and live births were significantly higher in the FET group than the fresh ET group. The incidence of multiple pregnancies, perinatal mortality, abortion in the first trimester, preterm delivery, and low birth weight were significantly higher among fresh ET group [38 (35.51%), 15 (14.50%), 72 (23.01%), 26 (8.30%), and 33 (10.54%), respectively] than in the FET group [25 (15.33%), 6 (6.87%), 63 (17.69%), 14 (3.93%), and 20 (5.61%); p<0.05]. In addition, the incidence of ectopic pregnancies, abortion in the second trimester, gestational diabetes, preeclampsia, and placenta previa were higher in the fresh ET group, but not significantly so (p>0.05).

Women who underwent IVF via FET showed more successful fertility and pregnancy outcomes compared to those who underwent IVF by fresh ET.