Calculation of the date of birth by the date of conception, by the last menstruation

2024 Author: Priscilla Miln | [email protected]. Last modified: 2023-12-16 00:21

Expectant mothers react to the news in different ways when they learn about pregnancy. Someone is very happy, someone is completely at a loss for some time, and someone may be in a panic. Not only the expectant mother can be nervous, but also the father, even if his thoughts about the offspring were purely positive. The main thing is to pull yourself together and remember that it is now impossible to expose yourself to stress in any case. But sooner or later everyone will be interested in one question: how to calculate the date of birth without going to the gynecologist? There are many calculation methods for this.

The most convenient time to calculate is in weeks. This method is generally accepted. In addition, the calculation can be carried out in lunar months and trimesters, at will and as it is convenient for anyone.

How to calculate the date by the monthly cycle?

Usually, childbirth occurs at 38-42 weeks. Calculation of ovulation, ultrasound examination - with the help of which it is possible to accurately determine the moment of conception and the future birthday of the baby. The simplest of the calculation methods is the calculation of the date of birth by menstruation. It is also called the method of obstetricians. But like othersmethods, calculating the date of birth by the last menstruation can only show the approximate day "X". Why is this date important?

Calculation of the date of birth by monthly obstetricians are considered the starting point for testing, registration of maternity leave. Statistics show that approximately 4% of women give birth to children at the exact time determined in this way. The rest either wait a couple more weeks, or give birth earlier.

How do obstetricians calculate the due date?

When a woman visits the gynecologist for the first time, the first thing the doctor should ask is what is the date of the last menstruation. Younger girls, in most cases, do not track the regular course of the monthly cycle. Although an experienced doctor will only need a start date.

This method is more suitable for women who have regular menstruation and do not have any failures. Calculation of childbirth is carried out according to the last monthly. The most popular was the Negele formula. The calculation is carried out as follows: 90 days are subtracted from the mark "first day of menstruation" and a week is added. For example, the date of menstruation is April 4th. We subtract 90 days and it comes out on January 4th, then we add a week and at the output we get January 11 - day X.

What does knowing the date of a future birth give?

This allows the doctor to:

• control the process of pregnancy;
• monitor the he alth status of mom and baby;
• prevent disease;
• determine how much the fetus has already grown;
• psychologically prepare a woman for childbirth and instillfeeling safe.

What gives knowledge to a woman:

• it becomes possible to track the change in your feelings;
• on time to prepare documents for maternity leave;
• properly strengthen the body and mentally prepare for the upcoming birth.

How to calculate the due date from the day of conception?

It is much easier to calculate the date of birth if the date of conception is known. Couples who are puzzled by the replenishment of the family try not to miss the favorable days of the cycle. But if everything happened spontaneously, you can still try to determine them at least approximately. Calculating the date of birth by the date of conception is not difficult, the main thing is to determine the time of the last unprotected intercourse. To do this, you need to remember a little biology. Or rather, how the process of childbirth goes. After menstruation, vesicles form in the ovary, which, by their occurrence, outstrip each other in growth and development rate. This is where female cells are formed:

• Achieving a peak in development, the cell breaks through its shell and heads towards the uterus. Passing through the genital tract, it is fertilized by spermatozoa. It is this moment that needs to be calculated.
• After 7 days, the fertilized egg reaches its target - the uterus and attaches to its walls.
• If the egg is attached, then the embryo begins to grow and develop. The hormone progesterone is an accomplice in this matter, it just helps the corpus luteum to be produced. In turn, the corpus luteum is a temporary gland that grows at the site of the bladder rupture. But if fertilization does not occur, then it is destroyed and leaves the body.
• Also, signs of pregnancy also apply to the mammary glands, which change their structure through the action of progesterone.

So, when the time is approximately determined, it is very easy to calculate the date of birth from the day of conception. You should add 280 days to it (the duration of a normal average pregnancy) and the output is an approximate day X.

When pregnancy occurs, colorless discharge can appear much more often, unpleasant pains in the ovaries begin and sexual desire for your partner increases.

How to calculate ovulation?

Ovulation is the day when the egg is ready for fertilization and leaves its habitat - the ovary. This is usually the 14th day of the menstrual cycle. The formula for calculating the due date in this case will be quite simple. The date of the last menstruation and the duration of the cycle are taken as a guideline. If the latter was regular, then 14 days are added to the beginning of menstruation. Women should always mark the start date of their period either on a calendar or in a special application in order to correctly calculate the due date from the date of ovulation.

Sperm fertilization occurs either immediately or within a few days. Therefore, only an uzist can accurately calculate the date of birth. It is advisable to do an ultrasound before the twelfth week of pregnancy, otherwise the specialist will not be able to determine exactly when the conception occurred. The doctor can determine the final figure by addingto the existing 28 weeks and another 14 days that have passed from the date of conception to ovulation.

Gynecological method for determining the date of delivery

Obstetrician-gynecologist - the closest friend and adviser of the future mother for all 9 months. When examining a pregnant woman, a specialist is able to determine the gestational age and date of delivery by increasing the uterus.

The baby grows, the uterus grows, and in this case, determining the future birthday of the baby will not be difficult. But only in the early stages. Since the uterus can increase in different women in different ways, the gynecologist may find it difficult to determine the time of delivery in the later stages. And such an effect is not useful.

Calculation date for the first fetal movements

At a time when nothing was known about ultrasound, the method of calculating the expected date of delivery by fetal movement was considered the most accurate. Of course, even today, a gynecologist, learning about the movement of a child, enters the date in a journal, but no one attaches much importance to this.

Based on this method, we can say that fetal movement occurs at about 20 weeks, respectively, to calculate the date of birth, you should add another 22 weeks to these.

The method is also rather inaccurate, since, depending on the physiology, different pregnant women feel the fetal movement in different ways and at different times. Someone earlier, and someone later. Those who lead an active lifestyle may simply not catch this slightest movement. Conversely, those whodue to the state of the body is bedridden, they can feel the movement of the fetus much earlier.

Ultrasound and due date calculation

So. Another way to calculate the expected date of delivery is an ultrasound in early pregnancy. At the beginning of pregnancy, the size of the fetus of different women is almost the same. You can determine the duration of your pregnancy with almost an accuracy of one day. The estimated date can also be calculated at later stages of pregnancy. But such a method is already undesirable to take as the basis for an accurate calculation of the date of birth. Because the calculation is based on the parameters of the head and limbs of the fetus, and children develop differently.

Some baby can weigh 5 kg, and someone 3 kg at the same time. Both options are the norm, as the difference may depend on genetics. It could be the height of the parents, the constitution, or how the mother ate during pregnancy.

It's just that in the first case, the expectant mother will be given more time on ultrasound examination than it actually is. Because of this, childbirth can begin later, and the woman in labor and gynecologists will rush things themselves, which can make the expectant mother very nervous and give a lot of false fears. For example, a post-term pregnancy.

The height of the uterine fundus determines the date of delivery

The height of the uterine fundus is the distance between the upper wall of the uterus and the pubic articulation. The uterus increases, and, starting from the 16th week of pregnancy, it becomes possible to measure its bottom through the abdominal wall. Up to this point, after how it resizesuterus, the gynecologist monitors with a vaginal examination.

How a fundus is measured

To measure dilation, the mother-to-be should prudently go to the toilet to empty her bladder. The pregnant woman should lie on the couch and straighten her legs. The doctor measures the distance. The whole procedure takes no more than one minute, but at the same time gives complete information about the growth of the child.

In order to accurately calculate the date of birth, you should look into the directory, which indicates the generally accepted dimensions of the bottom of the uterine wall for each of the periods of pregnancy. But we must not forget about the differences in the body, they can vary within three centimeters.

If the deviation of the height of the bottom of the uterus is below the set value, this may be an error either in determining the term, or the woman is the owner of a too wide pelvis (this is a feature of overweight women), or amniotic fluid is presented in small quantities.

If, on the contrary, the indicator is higher than the normal value, then there are reasons for this too. Either a large fetus, or pregnancy with multiple children, amniotic fluid enlargement may also occur.

There are many more reasons for the deviation of indicators in one direction or another. It all depends on the characteristics of the organism. Subcutaneous fat can influence, therefore, an increase in the circumference of the abdomen is taken into account. With their help, it becomes possible to calculate the approximate weight of the child. If, for example, we take the height of the bottom of the uterus 37 centimeters, and the circumference of the abdomen 96 centimeters, then multiplying them, it turns out 3552 gr.

Deviation from the acceptedan indicator greater than 3 cm indicates that the specialist should prescribe new examinations and tests, such as an ultrasound. These indicators will help determine the final tactics of childbirth.

Using a calculator

When pregnancy occurs, the calculation of the due date can be done in a special application. He can become a guide and custodian of information. An application, in particular, can contain a lot of useful information. For example, the first indicators of pregnancy, the stage of fetal growth can be described. The calendar will tell you when you are due to give birth and the app will give you advice on what tests to take and when to go for an ultrasound.

The calendar will help analyze and track the changes that occur during pregnancy with the body.

Determination of pregnancy due to weight gain

Another, quite truthful and quite effective method of calculating the term is adding weight. In general, for all 9 months a woman can gain from 9 to 14 kilograms. If twins, then maybe 21 kilograms.

The first trimester does not show significant weight gain, only about half a kilogram, then in the second trimester gaining a kilogram per month. Well, the third trimester is always marked by a very rapid weight gain of half a kilogram per week.

Why is only the estimated due date determined?

It is very difficult to calculate the time of the birth of a child, only a small part of women give birth exactly on the day that the doctor has scheduled. Common countthat pregnancy lasts 40 weeks or 280 days, but everyone's body is different, and everything is very individual. Someone can give birth earlier, and someone can wait a little, and this is absolutely normal. If there is a multiple pregnancy, then childbirth can occur much earlier than planned. Also, early childbirth can be caused by chronic diseases such as diabetes, pyelonephritis and others.

Why does pregnancy last 40 weeks?

During all 9 months, a child is formed in the womb. He grows, all the systems of his body begin to work smoothly, and by 37-38 weeks he is already completely ready to be born. If the pregnancy lasts a little longer, then apart from weight gain, nothing else happens to the child. Compared to the beginning of pregnancy, the baby is already quite large. Weight reaches about three kilograms, height is about 50 centimeters.