day 3 transfer
Embryo transfer performed three days after fertilization when embryos are at the cleavage stage.
Full Definition
A day 3 transfer refers to the placement of embryos into the uterus exactly three days after fertilization, when the embryos typically consist of 6-8 cells in the cleavage stage of development. This timing contrasts with day 5 transfers when embryos have reached the blastocyst stage. Day 3 transfers were historically more common but have become less frequent as laboratory techniques have improved, allowing for extended embryo culture to the blastocyst stage. The choice between day 3 and day 5 transfer depends on factors such as embryo quality, number of available embryos, patient history, and laboratory capabilities. Day 3 transfers may be preferred when few embryos are available or when there are concerns about embryo survival in extended culture.
Usage
Usage note: Always specify day number for clarity; distinguish from day 5 transfers in documentation.
In Context
- "Due to limited embryo numbers, a day 3 transfer was scheduled instead of waiting for blastocyst development." — Treatment plan modification
- "The day 3 transfer involved two high-grade cleavage-stage embryos." — Procedure note