Determining the estimated date of delivery following in vitro fertilization (IVF) relies on the precise dating of the embryo transfer. Unlike natural conception, where the exact date of ovulation may be uncertain, IVF provides a definitive starting point. This involves calculating forward from the egg retrieval date and the age of the embryo at the time of transfer to establish the gestational age. For example, if a five-day-old blastocyst is transferred, the calculation begins by adding five days to the retrieval date, then treating that date as approximately two weeks after the last menstrual period in a naturally conceived pregnancy.
Accurate dating is critical for several reasons. It enables healthcare providers to appropriately monitor fetal development, schedule necessary prenatal screenings and tests at the optimal times, and plan for delivery interventions if needed. It also offers expectant parents a more precise timeline for preparing for the arrival of their child. Historically, this method offers improved precision compared to estimations based on the last menstrual period in spontaneous pregnancies, particularly in cases of irregular cycles.
