The way to calculate the expected date of confinement (EDC) of IVF is different from "natural pregnancy". Many mothers often have a lot of doubts when calculating the due date of IVF and wonder which day it is.
The EDC is essential information in many prenatal examinations. Initial Down's syndrome screening, amniocentesis, high-level ultrasound, preterm or non-preterm, full term or non-full term, all these require knowing the due date.
So, today we will teach you: "How to calculate the EDC of IVF".
What is the expected date of confinement?
Before we calculate the EDC, let's understand what the EDC is.
Many people think that the "due date" is the day you will give birth, but it is not. The due date is actually the day when you reach 40 weeks of pregnancy or EDC (Estimated date of confinement) for short.
According to Wikipedia, a prenatal period is a medical concept used to predict the time of delivery. According to Naegele's rule, it is usually the first day of the last menstrual period (LMP) plus 280 days.
However, this calculation is actually based on the day of ovulation. The LMP + 280 days basis is only applicable if the menstrual cycle is regular 28 days and ovulation occurs on the 14th day. If the menstrual cycle is not a regular 28 days, this is not the calculation model and needs to be readjusted.
So, how to calculate the due date for IVF? Let's take a look!
The expected date of confinement of IVF
The calculation of the IVF due date is very simple. It is based on the "day of transfer embryo" and the date of implantation.
If day 5, 6, or 7 blastocysts is transferred, the transfer day is considered the 19th day of the menstrual period. So the transfer day minus 19 is the first day of the last menstrual period (LMP).
If the 4th-day embryo is transferred, the transfer day is considered the 18th day of the menstrual period. So the transfer day minus 18 is the LMP.
If the 3rd-day embryo is transferred, the transfer day is considered the 17th day of the menstrual period. So the transfer day minus 17 is the LMP.
If the second-day embryo is transferred, the transfer day is considered the 16th day of the menstrual period. So the transfer day minus 16 is the LMP.
The above calculation methods are applicable to both "fresh embryo implantation" and "frozen embryo implantation".
Next, a slight change in the question. (The concept of conversion, but the calculation is still the same)
Fresh embryo transfer
In addition to the calculation method of "embryonic days and transfer date" mentioned above, the EDC of a fresh embryo transfer cycle can also be calculated by "ovum pick-up".
The ovum pick-up day is considered the 14th day of the menstrual period. So the ovum pick-up day minus 14 is the LMP.
Frozen embryo transfer
In addition to the calculation method of "embryonic days and transfer date" mentioned above, the EDC of a frozen embryo transfer cycle can also be calculated by "the start day of progesterone supplementation".
The start date of progesterone supplementation is the simulated ovulation day, which is considered the 14th day of the menstrual period. So the start date of progesterone supplementation minus 14 is the LMP.
In conclusion, whether it is fresh embryo transfer or frozen embryo transfer, we can accurately calculate the LMP by using "ovum pick-up day", "the start day of progesterone supplementation", and "embryonic day", so the EDC can be calculated accurately.
The EDC that ERA result is not 120hr
If the ERA result is not 120 hours, how to calculate the EDC? The ERA result affects the "time required for progesterone supplementation", so the EDC of ERA transfer cycle is calculated by combining "date of transfer" and "embryonic days".
Therefore, regardless of the result of ERA, the EDC of ERA-FBT cycle is calculated by combining "date of transfer" and "embryonic days".
*Medical conduct should be discussed with your doctor, this article only reflects the current treatment status and recommendations.
