Pregnancy Calculation and Due Dates - Dr. Chaitra

How to calculate the due date for a natural conception?

Pregnancy is typically calculated from the first day of a woman’s last menstrual period. This is known as the “last menstrual period” (LMP) method. Pregnancy is considered to last approximately 40 weeks from the first day of the LMP, although the actual length of a pregnancy can vary slightly depending on factors such as the woman’s individual cycle length and the timing of ovulation. Healthcare providers may use ultrasound measurements to estimate the gestational age of the fetus and confirm the due date.

You can use an online calculator to estimate your due date.

How do you calculate the due date for an IVF conception?

The calculation of a pregnancy resulting from in vitro fertilization (IVF) is typically based on the date of embryo transfer. The embryo transfer date is considered to be equivalent to the LMP for the purposes of calculating gestational age and due date.

For example, if the embryo transfer took place on January 1, the pregnancy would be considered to be at 2 weeks of gestation on January 15, 4 weeks of gestation on January 29, and so on.

However, it’s important to note that the actual due date may be adjusted based on factors such as the number of embryos transferred and their development, as well as the mother’s individual medical history and health status. Your healthcare provider can provide more specific information and guidance on how to calculate and monitor a pregnancy resulting from IVF.

You can use an online calculator to estimate your due date (change the “Estimate based on to IVF transfer date”