What does gestational age mean?

Gestational age is the common term used during pregnancy to describe how far along the pregnancy is. It is measured in weeks, from the first day of the woman’s last menstrual cycle to the current date. A normal pregnancy can range from 38 to 42 weeks. Infants born before 37 weeks are considered premature.

What is the difference between gestational age and weeks pregnant?

While the gestational age measures how far a pregnancy has progressed in weeks, fetal age is the growing baby’s actual age. Fetal age is counted from the moment of conception. Thus, it is 14 days less than the gestational age, assuming a regular menstrual cycle of 28 days.

Does gestational age add two weeks?

While gestational age is measured from the first day of your last menstrual period, fetal age is calculated from the date of conception. This is during ovulation, which means that fetal age is about two weeks behind gestational age. This is the actual age of the fetus.

How do you calculate gestational age from LMP?

EDC by LMP is calculated by adding 280 days (40 weeks) to the first day of the last menstrual period. Gestation by LMP is calculated from the first day of the last menstrual period. Gestation by CRL is calculated: Weeks = 5.2876 + (0.1584 * Crown_Rump_Length) – (0.0007 * Crown_Rump_Length2).

Why is pregnancy calculated from date of last period?

If you were having regular periods before pregnancy, your doctor will calculate your due date based off of your last menstrual period. This goes back to the fact that in order to get pregnant, your body ovulated—or released an egg—roughly in the middle of your cycle and it was fertilized by sperm.

Does ultrasound show fetal age or gestational age?

Ultrasound measurement of the embryo or fetus in the first trimester (up to and including 13 6/7 weeks of gestation) is the most accurate method to establish or confirm gestational age.