What Does Days Post 5-Day Transfer (DP5DT) Mean?
Days post-5-day transfer (DP5DT) refers to the number of days that have passed since an embryo that developed for 5 days in a lab was transferred to a uterus during an in vitro fertilization (IVF) procedure.
In this case, a 5-day embryo called a blastocyst is transferred (as opposed to a different stage of development). Tracking days post-transfer is done to identify the day that a pregnancy test is most likely to give an accurate result.
FertilitySmarts Explains Days Post 5-Day Transfer (DP5DT)
The multi-step IVF process involves stimulating egg growth, retrieving eggs, fertilizing them in a laboratory with sperm, and allowing any resulting embryos to develop in a lab. (Read more detail about the IVF process.)
The embryos that result from this process can be frozen or transferred to a uterus, typically at either 3 or 5 days after fertilization. The decision depends on the information available for the embryologist to select the most promising one.
From fertilization, it can take around 14 days—otherwise known as the two-week wait—to get accurate results with a pregnancy test. A 5-day blastocyst is already 5 days into this wait, so it is typically 9 days until the results are known.
The following is a day-to-day list of approximately what might occur after a successful day 5 embryo transfer (see greater detail in our Implantation Calendar):
Day 1 post-5-day transfer, the blastocyst starts hatching out of its shell, and cells continue to divide.
2 post-5-day transfer, the blastocyst attaches itself to the uterine lining.
Day 3 post-5-day transfer, the blastocyst digs deeper into the lining and begins the process of implantation.
Day 4 post-5-day transfer, the blastocyst attaches itself to the blood supply held by the endometrium of the uterus.
Day 5 post-5-day transfer, implantation is generally complete, and the embryo has divided into cells that will become the placenta and cells that will become the fetus.
Day 6 post-5-day transfer, the placenta starts to secrete human chorionic gonadotropin (hCG), the hormone that is detected by pregnancy tests.
Day 7 post-5-day transfer The embryo continues to grow and produce hCG.
Day 8 post-5-day transfer The embryo continues to grow and produce hCG.
Day 9 post-5-day transfer, the bloodstream contains enough hCG for a home pregnancy test to be effective. A blood test is more reliable.