Comparison of maternal complications between fresh and frozen embryo transfer during gestation

Maternal complications in infertile women undergoing in vitro fertilization are an important discussion, and patients should be informed about these complications depending on the method of embryo transfer. In this study, maternal complications during gestation were compared between frozen and fresh embryo transfer in infertile women who underwent in vitro fertilization at Shariati Hospital from 2018 to 2021.

This study was a retrospective cohort study, and patient data were collected using archive files. From 396 in vitro fertilization patients, 302 were in the frozen embryo transfer group and 94 were in the fresh embryo transfer group. Patients in both groups were similar in terms of the number of transferred embryos and age (p>0.05). Data regarding threatened miscarriage, early miscarriage, placenta previa occurrence, gestational hypertension, preterm birth, gestational diabetes, and pre-eclampsia were gathered and compared between the two groups.

The rates of threatened miscarriage, placenta previa, gestational hypertension, gestational diabetes, preterm birth, and pre-eclampsia were not significantly different between the fresh and frozen embryo transfer groups (p>0.05). However, the early miscarriage rate in the fresh embryo transfer group was significantly higher (34% vs. 16.2%, p<0.001).

According to the results of this study, maternal complications, except early miscarriage, were not different between fresh and frozen embryo transfer. However, frozen embryo transfer is safer in terms of the early miscarriage rate.