Pregnancy is the first thing that interests future parents. As you know, rarely does a woman have a stable menstrual cycle of 28 days and ovulation on 10-14 days. As a result, pregnancy can occur immediately before the start of the next cycle or in the first days of the previous one. In some cases, pregnancy is diagnosed only in the second month, if there is a malfunction with the cycle (or there were minor discharge taken for menstruation).
How to calculate the gestational age and estimated date of birth?
The surest way is to go to the gynecologist or an ultrasound specialist. It is better to choose the second option, since you will know for sure that the pregnancy is uterine, how long you are, and whether there is a threat of interruption.
So, how to calculate the gestational age.
Determination by date of conception and ovulation
This method is only suitable if you know the exact date of conception. In this case, calculate your term is not difficult. But, as we said above, ovulation can occur not on the 14th day of the cycle.
If you follow the rules, then in the case of a 35 day cycle, ovulation occurs on day 17-18, but there are always exceptions. There are frequent cases when pregnancy occurred on “safe days”, that is, before or after ovulation. You can determine these few days at home with the help of tests or regular measurements of basal temperature (a schedule for several months will be required). During ovulation, the temperature rises to about 37-37.2.
Date of last menstruation
In this case, everything is extremely simple and many doctors, answering the question of how to calculate the gestational age, offer this option. Also, this method is called obstetric. You begin to count the weeks from the first day of your last period. Using this method, you can answer the question about how to calculate the date of birth of the child. The 40th week is the date of the alleged birth. But remember that each case is individual. And the baby can be born both at 38 and at 42 weeks, and this is the difference in a month!
Examination by a gynecologist
The best way to calculate the gestational age is to consult a gynecologist. You will either be examined on a chair or sent to an ultrasound scan. So you will know exactly what week of pregnancy at the moment.
Note that going to the doctor directly in the first days of the delay or even after one week is not worth it. The fact is that for short periods (up to 4 weeks) it is difficult to determine pregnancy. To avoid unnecessary worries, you should wait a bit.
Ultrasonography
The most accurate way to answer the question of how to calculate the gestational age by weeks. The first planned ultrasound is carried out at 12 weeks, when, in addition to confirming the presence of an embryo, many indicators are checked. But often this examination is required earlier to determine the course of pregnancy.
In the future, you may have a slightly different period for an ultrasound scan, since each child develops differently. Often, doctors put a delay in the development of the baby, when in reality this is not. The established weight norm of 3-3.5 kg can even be “demanded” from mom, not taking into account her physique. But babies born with a weight of 2.8 kg and 4 kg are developed in exactly the same way (that is, without any deviations).