When Does Embryo Transfer Occur?
The timeframe of embryo transfer is variable and dependent on a lot of factors, specific to the individuals in question. There are various events that precede the IVF cycle and that govern the trajectory of its completion – which is embryo transfer. Thus, it is vital that patients remain agnostic to specific calendar dates or timelines with embryo transfers.
For fresh transfers, the first day of the transfer cycle is the first day of stimulation medications – this typically day 2 to day 4 of the woman’s natural menstrual cycle. This is determined by the day of the egg harvesting and the subsequent developmental timeframe of the embryo. However, because both of these are variable factors the exact determination may be difficult. In general, most transfers occur either on day 3 or day 5 of the cycle – but even this may be variable with some of the blastocyst transfers happening even on the seventh day.
For frozen transfers, the timeframe once again differs from patient to patient. This is dependent on the parent’s cycle, the lining development, and response to medications being used. As the amount of time spent on estrogen therapy prior to the introduction of progesterone is highly varied and is determined with the help of ultrasound and blood work monitoring, the actual day of the embryo transfer is variable. In most circumstances, cleavage embryos are transferred four days from the commencement of progesterone, and blastocyst transfers take about six days in the normal course.