How to Calculate Pregnancy Age

Calculate Pregnancy Age

Knowledge of Calculate Pregnancy Age is still poorly understood by pregnant women. Though this is an important thing to be able to know the age of pregnancy is being undertaken. By identifying the age of pregnancy, a pregnant woman able to see what growth or organ growth is happening to her fetus, what her fetus needs and what it should and should not do during the pregnancy.

Also, by knowing the age of pregnancy, a pregnant woman can remember when the examination scheduled to be done either to the doctor or the midwife so that expected pregnancy is being undertaken to be healthy and produce the quality baby.

During this time most to be able to calculate the age of pregnancy still relies on experts either doctors or midwives, indeed this is a recommended for the accuracy of calculating the age of the pregnancy. Also, it usually calculates the gestational age by using a USG, which has a higher degree of accuracy by measuring the size of the skull, fetal length, heart size, kidneys, etc. However, there is no harm in pregnant women know how to calculate the gestational age that can be done alone.

How to Calculate Pregnancy Age

There are several ways that pregnant women can calculate the age of pregnancy that has a reasonable level of accuracy, including based on:

1. First day of last menstruation 

To be able to calculate the age of your pregnancy based on the First day of last menstruation can only be done by pregnant women who have regular and regular menstrual cycle (28-30 days). For estimates of gestational age based on the First day of last menstruation can use the Neagele formula, in addition to calculating gestational age, this method can also be used to calculate the day of birth estimation (HPL). The use of this formula is to add seven on the first day of the last menstrual period, then reduce the month by 3 and add 1 in the year. Meanwhile for the month that can not be cut 3, for example, January, February, and March, then the month plus 9, but the year remains not added or subtracted.

If your First day of last menstruation is 16 Nov 2008, then:
16 -11 - 08
+ - +
7 3 1
23 - 8 - 09 (this is the date of HPL)

So the estimated time of your birth is the date of August 23, 2009, while for the gestational age live count every 23 days, so at the date of December 23, means your pregnancy age stepped one month, 23 January 2 months pregnancy ... etc.
For the Estimated Day of Birth should be plus a plus or minus seven days.


Calculating the age of pregnancy by using the First day of last menstruation way is very easy to be done by every woman who was pregnant. Although without the help of a midwife or doctor, you can calculate your pregnancy age. You can calculate your pregnancy age every month even you can estimate your birthday later. However, for the expected date of the birthday cannot be determined with certainty, because this count is a mere estimate.


How to calculate gestational age using the First day of last menstruation way also has shortcomings for a woman who has irregular menstruation. Of course, there are also some women who forget the first day of her last menstrual period. So, they can not use the method of calculating the age of pregnancy according to this First day of last menstruation way.

2. The height of the womb

How to Calculate Pregnancy Age with high uterine peak method is to feel the top of the uterus protruding in the abdominal wall. The count starts from the pubic bone to the top of the uterus. For example, if the distance between the pubic bone to the top of the uterus is 18 cm, then your pregnancy is 18 cm. This calculation can also be done using a finger. Each 3-finger increment shows an increase of 3 weeks. If the top of the uterus is above the navel, the fingers increase at the age of 4 weeks. However, calculating the age of pregnancy in this way is rarely done.

In addition to the two ways mentioned above, there are two more ways that can be done is to detect the fetus's first fetal pulse and fetal movement detection first. But for both methods the accuracy level is less, because the fetal heart rate and fetal movement for the first time are still weak, making it difficult to detect.


  • It does not have to require special tools to calculate gestational age.
  • Can use fingers to calculate gestational age


  • Sometimes the calculation of gestational age is not accurate.
  • The calculation of gestational age only uses inaccurate tools.

3. Conduct HCG test

HCG or the abbreviation of Human Chorionic Gonadotropin is a peptide hormone produced during pregnancy produced by the embryo after the fertilization process subsequently generated by part of the placenta (syncytiotrophoblast).

HCG is a hormone that is luteotrophic in some species including music. HCG hormone testing is done to check a gestational age. HCG hormone testing is done by taking samples of urine or urine of a woman to determine the age of the pregnancy. If on examination found hormone HCG in urine, then it is possible that a woman is getting gestational age about 3 to 4 weeks.

Also, urine examination, HCG can also be performed on blood samples. HCG examination of the blood is performed to obtain the results of an undetected pregnancy or an ectopic pregnancy that is disturbing. When you experience morning sickness, it is possible that your hormone HCG has increased.


HCG hormone examination either through urine or blood samples has more definite advantages compared with other ways. This method further ensures a woman is pregnant or not. However, HCG examination through blood samples is more accurate than urine examination.


- This method can not be done by a woman who has irregular menstruation.

- This method will not get results for women who have hormonal disorders.

- This method may not be appropriate if done in mid-pregnancy.

- This method can not be done by a woman who uses a tool of contraception

4. Using a pregnancy calculator

Calculate Pregnancy Age by other means of using a pregnancy calculator. This method is an easy way for every woman to determine the age of the pregnancy. A pregnancy calculator that can be found easily like a free online calculator that is currently widely used by most women. In addition to the simple way, this method of pregnancy calculator can be accessed by anyone without having to waste time to go to the midwife or doctor.

Of course, the method of calculating gestational age with a calculator, you should still prepare the necessary data to calculate your pregnancy age such as HPHT and next menstrual period.


This method is somewhat simple and can be done by every woman. They do not have to go to the midwife or doctor to make sure their pregnancy is particularly for those who do not have time to consult.


Methods using a pregnancy calculator may not provide accurate pregnancy test results. The pregnancy calculator will only present test results according to HPHT whose truth and accuracy is still in question.

5. Ultrasound examination

Possible ways are more accurate than other methods of doing ultrasound examination. This technique is done by obstetricians who are already experts in this field. Examination using ultrasound method, usually done when the gestational age entered use 4 - 5 weeks after the menstrual period.

Ultrasound examination can also be done by a woman who wants to know the age of her pregnancy when entering the age of 8-18 weeks. How to Calculate Pregnancy Age in this method is more accurate because we can see whether it happens pregnancy or not. Ultrasound examination is also performed to determine whether pregnancy occurs in the uterus or outside the womb. It is to prevent the occurrence of ectopic pregnancy. The method of ultrasound examination can be done by a woman who does not know or forget the first day of her last menstrual period.


  • Inspection methods with ultrasound are more accurate than other methods.
  • This method can be done by a woman who has irregular menstruation.
  • Can know the exact position of pregnancy position.
  • Deficiency
  • Methods of ultrasound examination sometimes still have to remember the first day of last menstruation.
  • How to calculate gestational age is not accurate if done in mid-pregnancy.
  • Sometimes difficult to do if a woman using a tool of contraception
  • How to do ultrasound examination

For some women may be an ultrasound examination is considered trivial even they never do an ultrasound examination when pregnant. Particularly for women who live in rural areas that are not possible to perform the ultrasound examination.

However, this examination is critical to do because, in addition to seeing the pregnancy in the right place and position, ultrasound is also very necessary to know the development of the fetus. For those who may not yet know how an ultrasound scan is performed, we describe the following:

How to do ultrasound examination

Doing ultrasound examination paddle generally handled by a specialist gynecologist who would have been experts in their field. Handled by someone who is expert, of course, we will get a more accurate and more accurate explanation. The tool used to perform the ultrasound is a transducer stored on the abdomen connected to a screen. This screen will later show the state of the uterus and the fetus that you are biological.

Usually, an obstetrician looks at the condition of fetal development using endovaginal ultrasound. This tool will be inserted into the vagina so that the resolution to see the fetus is bigger and brighter. By checking your pregnancy using ultrasound, then you can be satisfied to see the development of the embryo inside.

What can be seen when performing an ultrasound exam?

As already mentioned above that ultrasound examination is more accurate when compared with other methods. In checking your pregnancy to the doctor with the endovaginal ultrasound device, then you can see three parts if possible you positive pregnant, including:

1. Fetal

This section is a lightweight fetal display that shows the legs and arms of the fetus with a very varied form depending on your gestational age.

2. Pocket of pregnancy

Of course, if you are pregnant, it will pimp the pregnancy bag as a place of development of your fetus from week to week. This pouch looks like a water bag that is a newly implanted fetus.

3. Yellow egg sac

In addition to the gestational sac, on ultrasound examination, you can also see an egg yolk that contains a unique structure prepared for fetal food when the placenta develops.

Only visible fetal sac

If you are on an ultrasound scan, the only thing you see is a fetal sac. So, you may have an ectopic pregnancy or better known as pregnancy outside the womb. Because, the fetal sac can be seen early in pregnancy, even if the fetus has not developed.

However, if the fetal sac is empty, it is hazardous because ectopic pregnancy can cause severe bleeding and even death for a woman. Ectopic pregnancy is caused by pregnancy that occurs in the fallopian tubes rather than the uterus. It is caused by an egg that has been fertilized by sperm does not move to the uterus, but growing in the fallopian tube.

For that reason, it is essential that you do an ultrasound examination if you want to determine whether you are pregnant in its place or not.

There is no heartbeat when the fetus is present

If you check your pregnancy with ultrasound early in pregnancy and find your pregnancy right in its place and you see a fetus. However, you do not hear the heartbeat of the fetus. Of course, you do not worry because this is a natural condition where the fetus in early pregnancy when gestational age is less than 16 weeks. Because usually the heartbeat you can hear when the pregnancy entered the early age of 16 weeks or about four months. If you experience this condition, an ultrasound examination will be performed on subsequent analysis.

However, if your pregnancy age has entered the age of 16 weeks or more than four months, then you should be aware. This condition can be caused by several things such as the fetus does not develop even fetal death in the womb. Therefore, it is essential for you who want to know the condition of your pregnancy by doing ultrasound examination.

Ultrasound examination in calculating gestational age

Indeed, calculating the age of pregnancy can be done by other methods. Some argue that the formula for calculating a more appropriate pregnancy can be done by knowing when the woman's first woman's first day. However, this method can not be said to be accurate for women who have irregular menstrual cycles. Therefore for women who have irregular menstrual cycles can be done with ultrasound examination.

In addition to seeing the development of the fetus and your fetal position, ultrasound examination is also performed to determine the gestational age and estimated birthdays. The ultrasound examination method will be more accurate if done in the first trimester of pregnancy. Because in this period, can be measured part of the fetal pole from end to end (CRL).

With this technique, it can be concluded the age of the fetus after late menstruation at 5-7 days. An ultrasound examination with ultrasound is recommended for women using contraceptive devices such as birth control pills and women with irregular menstruation.

The method and method most definitely calculate the age of the pregnancy.

Once we know the methods and methods commonly used to calculate the age of pregnancy, but inevitably you will ask what method is the most accurate in calculating the age of the pregnancy. There is no definite method and way to calculate a person's gestational age. Even an obstetrician cannot be sure when conception and ovulation take place inside the womb.

However, the calculation of the age of pregnancy is a reference for us to determine the gestational age and the estimated date of birth that we need. Regarding calculating pregnancy age, doctors can only predict when ovulation occurs and when your baby will be born into the world.

In fact, if we do not calculate the age of pregnancy by using any of the methods. It is possible for us to have difficulty in deciding the age of pregnancy and fetal development based on gestational age and can not predict when your fetus will be born. Of course, by knowing the age of pregnancy, we can prepare everything to welcome the birth of the little guy.

How to calculate the age of pregnancy for women with irregular menstrual cycles

For those of you who may have irregular menstruation cycles, then calculating pregnancy age is a bit difficult for you. In general, a regular menstrual cycle in a woman will last for 28 days, while for women with irregular menstrual cycles will last less or more than 28 days.

Calculating pregnancy age with irregular menstrual cycle can be done with ultrasound examination. With this method, you can see the development of fetal size that can predict the age of your pregnancy.

How to calculate pregnancy age based on trimester

Trimester means calculating the age of pregnancy with a span of 3 months. The trimester will be divided into three parts of the first trimester, second trimester and third trimester. The division of gestational age based on trimester, namely:

1. First trimester

At the age of pregnancy entering the first trimester, this can be said as the beginning of your pregnancy. The age of first-trimester pregnancy will take place early in pregnancy until the age of 13 weeks coupled with six days of pregnancy. This trimester usually calculates the gestational age from 1 - 3 months. In this first trimester, a woman will experience the symptoms of pregnancy as easily tired; dizziness is no exception with nausea vomiting every morning or a more commonly called morning sickness.

2. Second trimester

In this trimester a woman is not experiencing the symptoms of morning sickness, but there are drastic physical changes such as stomach that began to enlarge. Because at this time, a woman's appetite is more increased than in the early first trimester. Gestational age in the second trimester lasts from weeks 14 - 17 plus six days of pregnancy or about 4-6 months. In this second trimester, your pregnancy condition will be better.

3. Third trimester

It is the final trimester in a pregnant woman. At this time a baby is ready to be born. The third trimester lasts from the age of 28 weeks - the baby is ready to be born. Entering the third trimester is expected to be a pregnant mother keep her pregnancy well and meet the intake of food with adequate nutrition and nutrition to prepare energy and energy when labor will arrive. In this trimester a pregnant woman is more easily tired and worried about making for labor.

Those are some ways and methods that you can do to calculate your pregnancy age. Of course, you can choose what method if it is right for you because as we have explained above that each technique is done there are several advantages and disadvantages of each.

Although you can calculate pregnancy age independently, we recommend that you calculate the gestational age aided by a midwife or doctor to make your pregnancy calculation more accurate. Hopefully, the method and how to calculate the high pregnancy age can help you. Keep checking your pregnancy regularly to see how your baby is developing. Maybe useful!

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