The American College of Obstetricians and Gynecologists (ACOG) provide guidelines for the appropriate dating criteria to use during pregnancy. The dating criteria is based on the size of the fetus and the bodys response to the growth of the fetus.
The first step in determining an accurate due date is to identify the first day of the last menstrual period (LMP). The LMP is used as a reference point for doctors to estimate when the baby is due. It can also be used to determine when the fertilization of the egg occurred. The doctor may then use an ultrasound to confirm the LMP date and estimate the gestational age of the fetus. Ultrasound can show how far along in the pregnancy a woman is and can help doctors to determine if a babys growth and development are progressing normally.
In addition to the LMP and ultrasound, ACOG also recommends two other methods for dating a pregnancy. These include calculating from conception (when egg and sperm meet) and from ovulation (when an egg is released from an ovary). Conception can be estimated by subtracting 14 days from the first day of the LMP. Ovulation can be estimated by subtracting 14 days from the last day of the LMP.
The ACOG dating criteria aims to help doctors provide pregnant women with an accurate due date. The guidelines help doctors to track fetal growth and development and to assess any potential risks associated with a womans pregnancy. An accurate estimation of a babys due date is important so that doctors can provide maternity care and appropriately plan for delivery. If there are any discrepancies between the estimated due dates, then further testing may be done to ensure a safe delivery.
