To reach this stage of embryo transfer means that procedures such as ovulation stimulation, egg retrieval, fertilization, and blastocyst development have all been successfully completed. However, most families will face the first “choice” problem here: should we use fresh embryos or frozen embryos? There are various opinions online. Some say that fresh embryos are more successful because they can be used while still warm, while others claim that frozen embryos provide better implantation due to their stability. This article explains the real differences between these two options. The conclusion is as follows:There is no absolute superiority or inferiority. It depends on whether it suits your current physical condition and the specific plan you have in mind.

1. Fresh Embryo Transfer: Fast, but Requires Optimal Physical Condition

Fresh embryo transfer refers to the process of transferring embryos directly back into the uterus on the third day after egg retrieval, or on the fifth day when the embryos have developed into blastocysts. This method eliminates the need for freezing and thawing. The biggest advantage is that it saves time and effort. All steps—egg retrieval, embryo development, and transfer—can be completed in one cycle. This approach also reduces costs, making it particularly suitable for families who live far away and want to minimize travel time.

However, this method requires your body to be in optimal condition. The ovulation stimulation should be smooth, estrogen levels should return to normal after egg retrieval, the thickness and shape of the endometrium should be appropriate, and the embryo development should be synchronized with that of the endometrium. In other words, fresh embryos aren’t something you can choose at will. They represent a test of your body’s readiness. Only if you pass this test can you proceed with this method.

2. Frozen Embryo Transfer: Stable, with Option for Scheduled Transfer

Frozen embryo transfer involves storing embryos at -196°C using cryopreservation techniques. Once your body has recovered and the endometrium is ready, the embryos can be thawed and transferred. Modern cryopreservation techniques have high success rates, so the idea that frozen embryos become weaker is outdated.

This method is suitable for the following situations: