Embryo transfer in patients without polycystic ovaries, fresh or frozen?

This study investigated the live-birth rates following fresh or frozen embryo transfer in women without polycystic ovaries. They found there was no difference in the live birth rates following either frozen- or fresh-embryo transfer.

Embryo transfer is one of the final steps in a fertility treatment cycle. At this point the oocyte (egg) has undergone in vitro fertilization (IVF, fertilization of the egg by the sperm in a dish outside the body) and is ready for implantation in the women’s uterus.

In some cases, patients may choose to freeze the fertilized embryo for implantation at a later stage. There is evidence to suggest that frozen embryo transfer may result in higher live-birth rates than fresh-embryo transfer. Polycystic ovary syndrome (PCOS) is a condition caused by fluid-filled cysts on the ovaries. A recent study in women with PCOS found that frozen-embryo transfer resulted in higher pregnancy rates compared to fresh-embryo transfer. It is not clear whether this is also true for women without PCOS.

This study investigated if frozen-embryo transfer had a higher live-birth rate than fresh-embryo transfer In women without PCOS.

This study included 782 women without PCOS undergoing fertility treatment.  Patients were randomly assigned to undergo either frozen- or fresh-embryo transfer. Patients also began a standard medication regime to support implanation of the embryo.

36.3% of patients that underwent frozen-embryo transfer became pregnant compared to 34.5% of fresh-embryo transfer patients. The rate of live-births was also similar in both groups (33.8% for frozen versus 31.5% for fresh). 

This study concluded there was no difference in the live birth rates following either frozen- or fresh-embryo transfer.

This trial was conducted at a single site in Asia. The results may not extend to other ethnicities. Treatment protocols may also differ between hospitals.

If you have any concerns regarding embryo transfer procedures and fertility treatment, please consult with your doctor.