How to Calculate Gestational Age

Written by: Redaksi Klikdokter.com

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There are several methods that Mommy can do to calculate the gestational age, first is by using top of the uterus. An activity that is usually done by Mommy who wants to know the development of the fetus. 

The way to do it is also quite easy, just by palpating the uterus in Mommy’s protruding abdominal wall. This calculating method also enables Mommy to feel all activities of the fetus in the womb, sometimes Mommy can also feel the movements of the fetus. 

To be able to determine the age of pregnancy with this method, Mommy can start from the pubic bone to the top of the uterus. If the distance between the pubic bone and the top of the uterus is 18 cm, it is a sign of Mommy’s pregnancy over 18 cm.

This calculation can also be done by Mommy’s fingers. Each increment of three fingers from the top of the uterus will signify that the baby’s age is three weeks. If the top of the uterus has reached above the navel, Mommy’s pregnancy has reached the age of 4 weeks.

The benefit from knowing the gestational age, is to help estimating the ideal gestational age for childbirth, especially if Mommy is planning to perform a caesarean delivery because of certain reasons.

Menstrual Cycle Method 

This pregnancy calculation method is quite popular because it is rather simple. Actually there are also other calculation methods which could be considered more accurate by calculating Mommy’s menstrual cycle.

This method can be used to calculate the gestational age starting from the first day of the last menstruation. Unfortunately this can only be done for Mommy who has a normal menstrual cycle which is 28 to 30 days.

The formula used to calculate gestational age is using the Neagele formula. The use of this formula is done by adding  7 on the first day of the last menstrual period, and reduce month by 3 and add 1 year.

Pregnancy Journal

Using a pregnancy journal is not difficult. Here is the example. If Mommy’s last menstrual period takes place on May 6, 2012, then add the date with 7 (6 + 7), the result is 13. Then, subtract month with 3 (5 - 3), the result is 2. Next, the year plus 1 (12 + 1), the result is 13.

We may conclude that the birth of Mommy’s baby is around February 13, 2013. Mommy can calculate gestational age from now after knowing when Mommy starts to get pregnant and the Expected Date of Confinement (EDC). In order not to give more confusion, Mommy may create a pregnancy journal to keep track of Mommy’s pregnancy age every month.