Learning about pregnancy, expectant mothers react to the news in different ways. Someone is very happy, someone is completely at a loss for some time, and someone may be in a panic. Not only the future mother, but also the father can be nervous, 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, one question will begin to interest everyone: how to calculate the date of birth without going to the gynecologist? There are many calculation methods for this.
It is most convenient to calculate the timing in weeks. This method is generally accepted. In addition, the calculation can be carried out in the lunar months and trimesters, if desired and as it is convenient for anyone.
How to calculate the date on a monthly cycle?
Usually, delivery occurs at 38-42 weeks. The calculation of ovulation, ultrasound is something with 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 to calculate the date of birth by monthly. It is also called the obstetrician method. But, like other methods, calculating the date of birth by the last monthly can only show an approximate day "X". Why is this date important?
Calculation of the date of birth by a monthly obstetrician is considered the starting point for analysis, 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 another couple of weeks, or delivery occurs earlier.
How do obstetricians calculate the date of birth?
At the first visit to the gynecologist by a woman, the first thing a doctor should ask is what is the date of the last menstruation. Younger girls, in most cases, do not follow 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 have no glitches. The calculation of labor is carried out according to the last monthly. The most popular formula was Negele. The calculation is carried out as follows: 90 days are taken from the mark “first day of menstruation” and a week is added. For example, the date of menstruation is April 4th. We take away 90 days and come out on January 4th, then we add a week and at the exit we get January 11th - X-day.
What gives knowledge about the date of future birth?
Thanks to this, the doctor can:
- control the process of pregnancy;
- monitor the health status of mom and baby;
- prevent the occurrence of diseases;
- determine how much the fetus has already grown;
- psychologically prepare a woman for childbirth and instill a sense of security.
What gives knowledge to a woman:
- there is an opportunity to track the change in their feelings;
- in time to prepare documents for maternity leave;
- properly strengthen the body and mentally prepare for the upcoming birth.
How to calculate the date of birth on 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 family replenishment, 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. Calculation of the date of birth by the date of conception is not complicated, the main thing is to determine the time of the last unprotected sexual intercourse. To do this, remember a little biology. More precisely, how the process of procreation takes place. In the ovary, after menstruation, vesicles form, which, in appearance, are ahead of each other in growth and speed of development. It is here that female cells form:
- Reaching a peak in development, the cell breaks through its membrane and goes towards the uterus. Passing through the genital tract, it is fertilized by sperm. It is this moment that needs to be calculated.
- After 7 days, the fertilized egg reaches its goal - the uterus and attaches to its walls.
- If the egg is attached, the embryo begins to grow and develop. A collaborator in this matter is the hormone progesterone, 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 rupture of the bladder. But if fertilization has not occurred, then it is destroyed and leaves the body.
- Also, signs of pregnancy concern 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 on the day of conception. 280 days should be added to it (the term of an ordinary average pregnancy) and the result is an approximate X-day.
When pregnancy occurs, colorless discharge can appear much more often, unpleasant pain in the ovaries begins and sexual attraction to 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 date of birth in this case will be quite simple. The reference is the date of the last menstruation and the duration of the cycle. If the latter was regular, then by the beginning of menstruation 14 days are added. Women should always mark the start date of menstruation either on the calendar or in a special application in order to correctly calculate the term of childbirth by the date of ovulation.
Sperm fertilization occurs either immediately or within a few days. Therefore, an accurate calculation of the date of birth can only be done by a uzist. It is advisable to do an ultrasound before the twelfth week of pregnancy, otherwise the specialist will not be able to accurately determine when the conception occurred. The doctor will be able to determine the final figure by adding to 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 birth
The obstetrician-gynecologist is the closest friend and adviser to the expectant mother for all 9 months. Examining a pregnant woman, a specialist is able to determine the gestational age and date of birth to increase 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 initial stages. Since the uterus can increase in different women in different ways, a gynecologist may be difficult to determine the time of delivery in the later stages. And such an effect is not useful.
Date of calculation for the first movements of the fetus
At a time when ultrasound was not yet known, the method of calculating the estimated date of birth by moving the fetus was considered the most accurate. Of course, even today the gynecologist, learning about the movement of the child, writes the date in the journal, but no one attaches much importance to this.
Based on this method, we can say that the fetal movement occurs at about 20 weeks, respectively, in order to calculate the date of birth, you should add another 22 weeks to these.
The method is also quite inaccurate, because depending on 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 stir. Conversely, those who, by the state of the body, are bedridden, can feel the fetal movement much earlier.
Ultrasound and calculation of the date of birth
So. Another method of calculating the estimated date of birth is 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 an accuracy of up to one day. Calculation of the estimated date can be made 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 in different ways.
Some baby can weigh 5 kg, and someone 3 kg at the same time. Both options are the norm, since the difference may depend on genetics. This can be a high growth of parents, a constitution, or how a mother ate during pregnancy.
It’s just that in the first case, the expectant mother will be put on an ultrasound scan more time than it actually is. Because of this, childbirth can begin later, and a woman in labor and gynecologists will rush things themselves, which can be very unnerving for the expectant mother and will give a lot of false fears. For example, a postponed pregnancy.
The height of the bottom of the uterus determines the date of birth
The height of the bottom of the uterus is the distance between the upper wall of the uterus and the pubic joint. The uterus grows, and, starting from the 16th week of pregnancy, it becomes possible to measure its bottom through the abdominal wall. Until this moment, the gynecologist monitors the size of the uterus using a vaginal examination.
How is the measurement of the uterine fundus
To measure expansion, the expectant mother should prudently go to the toilet to empty the 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 make an accurate calculation of the date of birth, you should look in the directory, which indicates the generally accepted sizes 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 uterine fundus is lower than the set value, this can be a mistake either in determining the term, or a woman who has too wide a pelvis (this is a feature of full women), or amniotic fluid is presented in small quantities.
If, on the contrary, the indicator is above the normal value, then there are also reasons for this. Either a large fetus, or a pregnancy with several children, an increase in amniotic fluid 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 body. Subcutaneous fat can affect, 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 fundus of the uterus is 37 centimeters, and the circumference of the abdomen is 96 centimeters, then multiplying them, we get 3552 grams.
A deviation from the accepted indicator of more than 3 cm indicates that the specialist should prescribe new examinations and analyzes, such as ultrasound. These indicators will help determine the final tactics of childbirth.
Using a calculator
When pregnancy has occurred, the calculation of the date of birth can be carried out in a special application. He can become a guide and keeper of information. An application, in particular, can contain many useful things. For example, the first indicators of pregnancy, the stage of fetal growth can be described. The calendar will determine when the birth should happen, and the application will give tips on which tests to take and when to go for an ultrasound scan.
The calendar will help to analyze and track changes that occur during pregnancy with the body.
Determination of gestational age by weight gain
Another, fairly truthful and quite effective method of calculating the term is weight gain. In general, for all 9 months, a woman can gain from 9 to 14 kilograms. If twins, then there may be 21 kilograms.
The first trimester does not differ in significant weight gain, only about half a kilogram, then in the second trimester it is gained by 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 approximate date of birth determined?
It is very difficult to calculate the time of birth of a child, only a small part of women give birth on the very day that the doctor outlined. It is generally accepted that pregnancy lasts 40 weeks or 280 days, but everyone has different organisms, and everything is very individual. Someone can give birth earlier, and someone can wait a bit, and this is absolutely normal. If there is a multiple pregnancy, then childbirth can occur much earlier than planned. Also, early birth can be caused by chronic diseases such as diabetes, pyelonephritis and others.
Why does pregnancy last 40 weeks?
Throughout all 9 months, a baby is formed in the womb. It grows, all the systems of his body begin to work harmoniously, and by the 37-38th week he is already completely ready to be born. If the pregnancy lasts a little longer, then in addition to gaining weight, nothing more happens with the baby. Compared with the beginning of pregnancy, the baby is already quite large. Weight reaches about three kilograms, growth of about 50 centimeters.