Calculate the due date by the last menstruation. Calculate due date using a calculator. Determining the day of ovulation in the menstrual cycle
Calculation of the due date
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Calculation of the due date
Pregnancy is the most desired and long-awaited event for any woman. Therefore, there is nothing surprising in the fact that long before the documentary confirmation (two cherished stripes on the test) of an "interesting" situation, each of us already feels changes in the body.
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After your gynecologist diagnoses "pregnancy" and determines the exact date of conception, it will take only 280 days or 10 obstetric months before the fetus is fully ripe. At the same time, one should not clearly focus on these indicators. They are very individual and depend on the physiological characteristics of a particular woman and on the environment in which she carried the child. It is known from practice that only 4% of babies are born clearly after 280 days. The rest, due to various factors, may be born earlier or later. In order to find out the approximate date of birth of your baby and determine the so-called gestational age, they are guided by the first day of the last menstruation.More calculators:
Do you have any more questions? read the answers below:
1. How accurate is the calculation for the day of conception
To understand the accuracy of the calculation, you need to decide on the calculation method. It's no secret that conception is possible only during the period of ovulation, during which a mature egg is released from the ovary. The duration of the menstrual cycle is an individual feature of every woman. On average, it can be from 28 to 35 days.
Ovulation occurs in the middle of the menstrual cycle. The exact date can be determined by ultrasound, using special home tests for ovulation, or by measuring basal temperature. Some women have special signs on this day, by which she can determine that today is ovulation. It is on this day that conception occurs, which may not coincide with the day of physical intimacy, since sperm are able to maintain their viability in a woman's body for a week.
Knowing the day of conception, it is also a tribute to ovulation, it is quite easy to calculate the date of birth: you just need to add 266 days. This will be the estimated due date. The accuracy of these calculations will directly depend on the accuracy of determining the date of ovulation. If your cycle is not constant, and you are not sure about the date of conception, then this technique may give some error.
2. How to calculate the date of birth by menstruation
This method of calculating the expected date of birth is used in antenatal clinics. It is also called obstetric term. To determine the expected date of birth, you need to know the date of the beginning of the last menstruation. This day is the starting point for the calculation. If the duration of the menstrual cycle is 28 days, then you can use the Negele formula, according to which the date of birth is calculated as follows: from the day of the beginning of the last menstruation, three months are subtracted and seven days are added. You can also use another technique: 280 days are added to the date on which the first day of the last menstruation fell. According to scientific data, it is this period that is necessary for the ripening of the fetus.
But if your cycle is longer or irregular, then it will not be entirely correct to calculate the date of birth by menstruation. If the duration of the menstrual chicle exceeds 28 days, then labor is likely to occur later, if on the contrary, then earlier. If the cycle is not regular, then this method of determining the expected date of birth will be rather indicative and cannot be used as a basic technique.
3. How to calculate the date of birth by the first stirring
Often, to determine the expected date of birth, they use such a landmark as the very first movement of the baby inside the abdomen, more precisely, the moment when the mother was able to feel the movement of her baby. Therefore, it is also called intuitive and experts consider it inaccurate. Moreover, if a woman gives birth for the first time, then she will most likely feel the first movement in the twentieth week of pregnancy. If a woman is about to give birth again, and she already knows what exactly she should feel, then the first movement of the fetus in most cases is felt at the eighteenth week. Now, in order to calculate the date of birth by the first movement, if the pregnancy is the first, you need to count exactly 20 weeks from the date of the first movement. If a second birth is coming, then only 18 weeks need to be counted.
As practice shows, quite often many primiparas and women giving birth again begin to feel the movement of their baby already at a period of 15-16 weeks. But there are also mothers who felt the first movement of their baby only at the period of 21-22 weeks.
Do not rush to apply this technique in practice to determine the expected date of birth, since in fact it is not known which category of expectant mothers you belong to.
4. How to calculate the date of birth by ultrasound
The most accurate method for determining the date of birth is considered to be diagnostics by ultrasound (by ultrasound), but it must be used very early, no later than the twelfth week. This method allows you to diagnose the gestational age with an accuracy of one day, thus indicating the approximate date of conception and, accordingly, the date of birth.
Later, the gestational age is determined by the size of the baby's head and limbs. But this conclusion does not allow us to accurately diagnose the expected date of birth, since each child develops completely individually, having a different weight not only at the moment of birth, but also during its intrauterine development. Therefore, when determining the date of birth in the second trimester, an error of up to seven days appears, and an ultrasound scan in the third semester hardly makes it possible to judge the duration of pregnancy, based on the intrauterine dimensions of the baby.
Thus, in order to accurately calculate the date of birth by ultrasound, it is necessary to undergo an examination during the first three months of pregnancy. Otherwise, the intrauterine dimensions of the baby will not allow you to accurately determine the date of the expected birth.
Once you find out that you are pregnant, you are overwhelmed with incredible joy. The first time you go and just give everyone your happiness. Over time, when the term becomes a little longer and the first euphoria passes, you can't wait to find out when your baby will be born. You want to plan your childbirth, at least knowing approximately when that day will come, so that you are ready for anything. Today we will show you how to calculate your due date.
Pregnancy is always a joy
Due Date Calculator
Calculation of the due date
How to calculate due date by conception date?
To be perfectly honest, everyone wants to know the due date. There are two ways:
How else can you calculate your due date?
There is another method that is popular with doctors. With this method, calculating the due date is not as difficult as many people think. Initially, you need to decide what kind of cycle you have. After that, you must remember when the last critical days were. The calculation should be based on when the last period was. In medicine, the first day of your period will already be considered your child's possible birthday. The estimated date will be calculated from the weeks, which are also called the medical weeks of pregnancy. What is the difference?
Everything is very simple. If in ordinary life we are accustomed to the fact that pregnancy lasts exactly 9 months, that is, approximately 36 weeks, then according to medical standards, this period is 4 weeks longer. In simple terms, the pregnancy will last 40 weeks. The estimated due date is calculated from the critical days plus 40 weeks. It is quite easy to calculate all this. Should not get confused.
The estimated due date determined in this way is considered not entirely reliable, and doctors do not rely on it.
You just need to know your cycle and know when is the last day of your period. The preliminary due date is very easy to calculate. There is a special calculator that will help make the calculation fast. Of course, the sex of the child cannot be calculated using this method.
There is also a table for determining the date of birth. You can also find it on the Internet. In addition to these tables, you can usually find tables for determining the sex of the child. They are usually also based on personal data (menstruation, ovulation). A special calculator will help you quickly calculate your cycle, and you will know when your baby is approximately born.
The easiest way to figure out when your baby is due is to go for a regular ultrasound. It is believed that this is the most reliable way. There, the calculation is based on the stage of fetal development.
Estimated due date(PDR) is considered the day when the gestational age is exactly 40 weeks. Although a full-term pregnancy is considered already upon reaching the full 37 weeks, and in some cases a healthy full-term baby can be born at 42 weeks of gestation, it is still customary to focus on 40 weeks, since most births begin precisely at this time.
The importance of calculation estimated date the birth of a baby is beyond doubt, and the point here is not only the desire of the parents to prepare for the appearance of a new family member. The medical side of the matter is also important. Let's list the reasons why a doctor leading a pregnancy needs to know the expected date of birth.
Fetal growth and development... It is important for a doctor who monitors the course of pregnancy to know how much the developing baby corresponds in size to the gestational age (which is calculated based on the expected date of birth) in order to timely diagnose such a serious complication as intrauterine growth retardation (IUGR), which is a consequence of placental insufficiency (pathology , in which the placenta is defective in providing the fetus with everything necessary for growth and development). Timely adequate diagnosis, and, consequently, treatment of this complication is of great importance for the further full development of the baby.
Prevention of pregnancy complications... In the process of observation, the obstetrician remembers that at various stages of pregnancy, the development of certain complications is possible, in connection with which the timing has been determined in which it is necessary to carry out diagnostic measures to identify complications, their prevention and treatment (for example, prenatal screening - diagnosis congenital malformations of the fetus - should be carried out at clearly defined periods of pregnancy, and if these periods are not observed, its diagnostic value is sharply reduced). With diseases such as diabetes mellitus and hypertension - if the course of the disease worsens or the treatment does not give a positive effect - it may be necessary to deliver before spontaneous labor begins. Then the doctor needs to know in order to ensure the maximum possible degree of fetal maturity in this clinical situation.
When to go to the hospital
If there are indications for early hospitalization before delivery, it is important to correctly determine the timing in which the pregnant woman should go to the hospital... Indeed, with too late hospitalization (for example, on the eve of a planned cesarean section), there is a risk of not having time to carry out the required amount of examination and preparation for delivery, and too early hospitalization is not advisable, since a long stay of the expectant mother in the hospital can lead to an increased level of anxiety, stress the day before childbirth. The timing of antenatal hospitalization for various complications during pregnancy may vary. For example, with diabetes mellitus, it is necessary to hospitalize a pregnant woman no later than 36 weeks. With a transverse position of the fetus and placenta previa, the expectant mother should be in a hospital no later than 37 weeks (since during this period the body prepares for childbirth, which is a great danger due to prenatal rupture of amniotic fluid in the case of a transverse position of the fetus and the development of bleeding during presentation placenta). Women with breech presentation and anatomically narrow pelvis are sent for antenatal hospitalization at 38–39 weeks of gestation in order to have time to conduct a full examination, choose a method of delivery, and prevent pregnancy overdue.
How to calculate your due date
For determining expected due date several methods are used.
Obstetric term(by the date of the last menstruation). It is generally accepted to consider the date of the first day of the last menstrual period as the reference date for the menstrual cycle - that is, the complete menstrual cycle is calculated as the interval from the first day of menstruation to the first day of the next menstruation.
For calculation expected due date by the date of menstruation, there are two ways:
280 days are added to the date of the first day of the last menstruation (this is the average duration of pregnancy, counting from the date of menstruation).
Formula Negele: from the first day of the last menstruation 3 months are subtracted and 7 days are added. For example, the last menstrual period was May 10 - subtracting 3 months, we get February 10, and adding 7 days, we get February 17 - this will be the estimated date of birth by the date of menstruation (we will assume that on February 17, the gestation period will be a full 40 weeks, and therefore, around this time, labor should begin).
Fetal term(by date of conception or by ovulation). The likelihood of pregnancy is highest on the day when ovulation occurs - the process of the release of a mature egg from the ovary. This usually occurs in the middle of the menstrual cycle (for example, if the menstrual cycle is 28 days, then ovulation occurs on the 14th day, and if the cycle is 32 days, then on the 16th day).
Given that the egg is capable of fertilization within 24 hours after ovulation, and the life span of a sperm is on average 72 hours (in some cases it can reach 4-5 days), the probability of fertilization is not 1 day, but much earlier - starting from 9 -10th day of the menstrual cycle (with a 28-day cycle). This circumstance significantly complicates the determination of the expected due date by the date of conception. It is possible to establish the due date of conception when a woman knows exactly the date of ovulation (for example, she monitored the basal temperature or, for medical reasons, ultrasound monitoring of folliculogenesis, the process of egg maturation, was carried out). To determine the PDD, 266 days (since this is the true duration of pregnancy) or 38 weeks are added to the date of conception.
With a regular menstrual cycle (lasting 28 days), there is no difference between calculations by the date of the last menstruation and the date of conception, therefore it is most convenient and informative to determine by the date of menstruation.
By the date of the first appearance in antenatal clinic... This method of determining the duration of pregnancy and childbirth will be as informative as possible if the expectant mother consults a doctor before 12 weeks of pregnancy. When registering, in order to be sure of the fact of pregnancy and to establish its duration, the doctor will conduct an examination on a gynecological chair to determine the size of the uterus. It begins to increase from 5-6 weeks of pregnancy, acquires a spherical shape. In addition, during pregnancy, the uterus becomes soft (outside of pregnancy, the uterus has a pear-shaped and dense consistency).
Determining the size of the uterus during a gynecological examination, the doctor specifies which gestational age corresponds to an increase in the uterus. For example, at 5-6 weeks, the uterus becomes the size of a hen's egg, at 7-8 weeks - the size of a goose's egg, by 12 weeks it reaches the size of the newborn's head and its bottom (this is the name of the upper part of the uterus) is already possible to palpate (feel) through the front the abdominal wall without resorting to vaginal examination. Starting from the second trimester, according to the height of the fundus of the uterus, you can roughly determine the gestational age: by 16 weeks, the bottom of the uterus is in the middle of the distance between the bosom and the navel, by 24 weeks - at the level of the navel.
It is important to remember that the longer the gestation period, the higher the error may be in determining it according to this parameter, since the height of the uterine fundus depends on many individual characteristics: the number of births in the anamnesis, the size of the fetus, gynecological diseases (for example, with uterine myoma, the size of this organ will be more than the norm for a given period), the anatomical features of the organism of the expectant mother, etc. Therefore, the examination performed before 12 weeks of pregnancy is of greatest importance for determining the PDD upon arrival at the antenatal clinic, then the doctor will be able to determine the duration of pregnancy by the size of the uterus ...
According to ultrasound data... Determination of the gestational age and expected due date it can be done quite accurately if an ultrasound scan is performed in the first trimester of pregnancy (up to 12 weeks). When conducting an ultrasound examination at the earliest stages (and it is possible to see a fertilized egg by ultrasound from 3-5 weeks of pregnancy, the embryo begins to be clearly visualized a little later - starting from 5-6 weeks of pregnancy), the average inner diameter of the ovum and the coccygeal-parietal size are measured CTE of the unborn child. For each gestational age, there are certain KTP standards, measured in millimeters, by comparing which with the data obtained, you can fairly accurately establish the expected date of birth.
In the second and third trimesters gestational age It is established based on the measurement of certain fetal dimensions: such as biparietal size (the distance between the parietal tubercles, or large transverse size of the fetal head), head circumference, abdominal circumference, fetal chest and abdomen diameter, femur length. The data obtained also make it possible to judge the duration of pregnancy, but it must be remembered that the larger it is, the greater the likelihood of an error. This is due to the fact that as the fetus develops, depending on the characteristics of the course of pregnancy, the presence of diseases of the mother, hereditary factors, the size of the fetus, which is used to judge the duration of pregnancy, will differ significantly. One mother will have a child weighing 2600 g and height 48 cm, and another - 4500 g and height 57 cm, which is completely normal, since all people have individual anthropometric characteristics. Thus, it is possible to determine as accurately as possible the duration of pregnancy according to ultrasound data in I trimester of pregnancy or around 20 weeks, when there is the greatest agreement between fetal size and gestational age.
By the date of the first stir fetus. PDR can also be determined by such a parameter as the date of the first movement of the fetus. In this situation, it is more correct to talk about the date when the pregnant woman first felt the fetal movement, since the fetus begins to actively move in the uterus from 8 weeks of pregnancy, it is just that the mother does not feel this due to the too small size of the child. It is believed that primiparous women first feel fetal movements on average from 20 weeks of pregnancy, and multiparous women - from 18 weeks, therefore, to determine the expected term of birth according to this parameter, 20 weeks are added to the date of the first fetal movement in primiparas, and in multiparous women - 22 weeks.
It should be noted that this method definition of DA considered additional, or auxiliary, since fetal movement is a very subjective sensation, moreover, future mothers do not always celebrate it for the first time in the above terms. For example, primiparous women may first feel fetal movements in later stages of pregnancy - after all, this is still an unfamiliar sensation, and at first they may confuse it with intestinal motility or simply not notice. Women with a pronounced layer of subcutaneous fat may first feel fetal movement 1-2 weeks later. Multiparous women, on the other hand, may notice the first movements at an earlier date (at 16-17 weeks), since they already know how this happens. These circumstances may reduce the accuracy of determining the expected due date by the date of the first fetal movement.
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Why calculate the DA by several parameters?
The need to calculate estimated due date according to several methods, it is simultaneously due to the following factors. Firstly, despite the availability of the most modern methods for assessing the duration of pregnancy, it is almost impossible to predict when a woman will begin labor (with an accuracy of the day). Secondly, some of the data on which it is customary to calculate the estimated date of birth, for various reasons, may be uninformative. For example, with an irregular menstrual cycle, the calculation of the PDD by the date of the last menstruation will be inaccurate, and with a late first visit to the antenatal clinic, the presence of gynecological diseases (uterine fibroids) or overweight, it will be difficult to determine the duration of pregnancy by the size of the uterus. Given these circumstances, the doctor sets the expected date of delivery based on the maximum amount of data to clarify the time interval in which labor is most likely to begin. As a result expected due date most often it is defined not as one specific number (for example, January 15), but as a time period (for example, from 12 to 17 January).
Nevertheless, even when the estimated date of birth is correctly calculated according to all the data, not all pregnant women begin to give birth, since the duration of pregnancy in each case depends on many factors. That is why the date of birth is called the estimated date.
Duration of pregnancy, and therefore, the period when regular labor will develop is individual, moreover, it is calculated based on the fact that labor will begin after reaching the full 40 weeks, but pregnancy is considered full-term after 37 weeks, so labor can begin in 2-3 weeks before the expected due date. A variant of the norm is the development of labor in the 41st week of pregnancy.
Thus, on duration of pregnancy and the onset of labor is influenced by many factors, among which the characteristics of the history play an important role - the age of the expectant mother, the number of previous births, the presence of miscarriages, premature births and / or abortions in the past, existing chronic diseases. In addition to these features, for a period onset of labor the peculiarities of the course of this pregnancy also affect. For example, with multiple pregnancies, childbirth often begins earlier than with a singleton, and the gestation period is inversely proportional to the number of fetuses (the more fetuses, the shorter the period), which is due to overstretching of the uterus. With the development of placental insufficiency (pathology of the course of pregnancy, in which one or more functions of the placenta are disrupted, leading to insufficient provision of the fetus with everything necessary for growth and development), both early development of labor and an increase in the duration of pregnancy by 1-2 weeks are possible.
Despite the impossibility of absolutely accurate determination of the date of birth, it is still necessary to correctly calculate the DA. Focusing on the expected term of delivery, the degree of biological readiness of the organism of the expectant mother for childbirth (determined by the doctor according to a number of signs, one of the main is the degree of maturity of the cervix - the presence of biological readiness for childbirth is the key to the physiological course of childbirth and a favorable outcome for the mother and fetus) and the state fetus, the doctor will be able to timely resolve the issue of the need for preparation for childbirth, antenatal hospitalization, drug treatment, etc.
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Doctors-gynecologists say: the duration of the menstrual cycle affects the date of birth.
The standard menstrual cycle is 28 days. If the cycle is greater than this value, then the pregnancy lasts longer than the prescribed period. If less, then the woman can give birth earlier than the prescribed date.
Deviation in the term of delivery ranges from 5 days.
In the calculations for determining the date of birth, you can be mistaken if you accept the bleeding after fertilization of the egg in the last menstruation.
How to determine the due date by the last menstruation
This method of calculation is used by obstetricians-gynecologists, since it is the most accurate and convenient.
From the date of the last menstrual period, the obstetric gestational age is considered, which may differ from the period calculated for conception.
When calculating the due date from the last menstrual period, the gestational age is 10 months. 
Required data for accurate calculation
Required data for calculation:
- The duration of the menstrual cycle. To be sure of the accuracy of the indicator, you need to know how many days pass between the indicated dates of the month. The normative number is 28 days. Less often, the cycle can last 21-33 days;
- The nature of the menstrual flow. The parameters and duration of menstruation will help to accurately determine the date of birth by the last menstruation. The norm is considered uniform in consistency, medium abundance and monthly recurring bleeding;
- Cyclicity. The discrepancy between cycles can be within 1-2 days. Then they are considered regular. If each time the dates are shifted by more than 5 days, then the cycle is considered irregular. In this case, calculating the exact date of birth by the last month may be ineffective.
For this calculation, a formula developed by obstetrician Franz Negele is used. The expectant mother needs to know exactly the period of the last menstruation. 
The calculation algorithm is as follows: 7 days are added to the 1st day of the last menstrual cycle and 3 months are subtracted.
For example, the date of the 1st day of the last menstrual period is March 20th. So March 20 + 7 days - 3 months. = December 27.
This method can be used at home, as long as the woman has a regular menstrual cycle lasting an average of 28 days.
Determining the day of ovulation in the menstrual cycle
In order for pregnancy to occur, the egg in the woman's body must mature to be the basis for the embryo. Such maturation occurs only on the day of ovulation.
Ovulation occurs during the fertile phase of the menstrual cycle., that is, the period when the egg matures and leaves the ovary. Within 24 hours the most favorable time for conceiving a child. 
Methods for determining ovulation:
| Phases of ovulation in the female body | Main characteristics |
| Follicle origin | The duration of the phase is 11-17 days. The norm is 14 days, provided a regular menstrual cycle lasting 28 days. |
| Follicle release and transport to the uterus | The life span is 1 day without sperm fertilization. Therefore, to accurately determine the date of birth by the last menstruation, you need to know the date of ovulation. |
| Appearance of the corpus luteum | The corpus luteum is a gland that forms after ovulation and connects the hormones estrogen and progesterone. Plays an important role after fertilization of the egg. The vital activity of the corpus luteum is 14 days, in rare cases - 12-13 days. |
To calculate ovulation, you need to subtract the number 14 from the duration of the menstrual cycle. And then count the resulting number from the date of the last monthly. Since the menstrual cycle is different for everyone, the calculation must be performed based only on your individual data.
In order to determine the date of birth by ovulation, you need to know its date and add 266 days to it.
The discrepancy in the data may be 5 days, this is the time while the sperm lives in the lining of the uterus, that is, pregnancy can occur after ovulation. 
Is it possible to determine the due date with an irregular cycle
Determining the date of birth by the last menstruation with an irregular cycle is quite difficult, but possible.
The main ways to identify the date of birth with an irregular cycle:
- determination by ovulation. For this, 28 days are taken as the basis - the average. From the first day of menstruation, 14 days are counted. And this number will be considered the day of ovulation;
- determination of the date of birth according to the table.
Table for determining the date of birth by the last month
It is necessary to find in the red line the 1st day of the last menstrual cycle and in the yellow line there will be the corresponding date of birth.
For example, the date of the 1st day of the last menstruation is January 5, then the corresponding date of October 12 will be the estimated date of birth.
Dates from 1st to 15th day of the month
Dates from 16 to 31 days of the month
Determine the due date by the last monthly mono using this table. Methods for determining the birth date by ovulation and the last month do not give one hundred percent guarantee, they can only be guided by.
Calculator - how to calculate due date online
For the convenience of calculating the date of birth of the expectant mother, you just need to find online calculators in the Internet search and drive in the necessary information.
What are the online calculators for calculating the due date:
The online calculator will be useful for determining the due date by the last menstrual period and for those girls whose menstrual cycle is far from ideal.
To do this, add up the numbers of the last menstrual cycles for 6 months and calculate the arithmetic mean by dividing the value by 6.
For example: 31 + 28 + 30 + 26 + 32 + 27 = 174. Now divide 174 by 6. The result is 29. This is the average cycle time. 
Now you can safely enter the required data into the online calculator.
Why are the results of determining the date of birth approximate
There are many ways to determine the date of birth, but it is almost impossible to accurately identify it for a number of reasons.
Deviations in the date of delivery may be due to the following factors:
Note! If the birth of a child occurred later or earlier by 1-2 weeks of the planned date, then this is considered the norm.
Determining the date of the upcoming birth will not be difficult if you know all the necessary data and have free time to calculate it.
Even the approximate date and period of childbirth, in which a child may be born, makes it possible to prepare in advance and acquire everything you need.
This video will help you determine your due date by your last period and in other ways.
In this video, you will learn how you can calculate the gestational age by the last menstruation.
Hello dear readers! Today I propose to talk about a very intimate, but important topic that worries almost every expectant mother - "How to correctly calculate the due date?" The birth of a child is the main event in a woman's life. For example, I was really looking forward to him, and at the same time I was afraid. Then my gynecologist told several ways that helped me to accurately calculate this date. I will gladly share this information with you. Are you already curious? Then let's start.
Determine the day of birth by the day of conception
Determining the exact date of birth of a child by the date of pregnancy is the most common method used by many expectant mothers. Add 9 months to the estimated date of conception, and you're done! Did you also calculate the time of delivery by this method? I hasten to upset you - these are incorrect calculations! The thing is that the process of carrying a child lasts 280 days, not 9 months.
Your personal ovulation calendar will help you determine this important day. The thing is that the moment of fertilization of the egg sometimes does not coincide with the time when the decisive sexual intercourse took place. Did you know that sperm cells can live in a woman's body for up to 7 days, and stubbornly "wait" when fertilization can be carried out?
Most often, it is the day of ovulation that is the day of conception. It is enough to add 280 days to it, and you will know when day "X" comes.
How to correctly calculate the due date
If you did not manage to carry out the appropriate calculations by the date of conception, use your personal menstruation calendar to calculate the baby's birthday. Every girl has it. Is not it? Any gynecologist will tell you that the regularity of the menstrual cycle is very important.
Doctors calculate the time of delivery using a special Negele formula. This method is suitable only for those girls whose menstrual cycle works like a clock and lasts 28 days. Let's try to use the formula together with a specific example.
The general wording is as follows - from the first day of the cycle, you need to subtract 3 months and add exactly 7 days. For example, my last period started on September 28th. I subtract 3 months from this date - it turns out June 28. Add 7 days, and we get the date - July 5th. This is a very simple yet effective way. Believe it or not, the time I calculated exactly coincided with the birthday of my baby.
Ultrasound is the best way to determine the "X" day
Medicine does not stand still. Gradually, new equipment appears, which allows you to carry out the most accurate studies of the body of a future woman in labor. With the help of an ultrasound examination, the gynecologist can determine the size of the fetus, and from this data establish the PDD (estimated date of birth).
I had different periods for menstruation and ultrasound, so I had to use another method, which I will discuss below.
In order for the survey results to be as accurate and truthful as possible, you need to perform. If you see your doctor too early, he will not be able to see anything, as the fetus is very small in early pregnancy. The ideal time to determine the PDD by ultrasound is 10-14 weeks.
The main thing is not to miss this moment, since then the baby will begin to actively grow and develop, and his physiological changes will depend solely on the individual characteristics of the organism. If you sign up for the first ultrasound examination in the 2-3 trimester, the gynecologist will not be able to determine the PDD accurately.
The baby moved in the stomach - it's time to calculate the exact due date
Did you know that you can also find out the PDR by the movement of the fetus? It is about this method that I promised to tell you at last. Well, promises must be kept! Of course, this method can be considered rather approximate and imprecise, but it has a place to be. The thing is that a girl who gives birth for the first time feels the fetal movement a little earlier than a mother with experience.
Be sure to remember the day when you first felt that the baby inside you began to move. One of these methods can be used:
- If you will be giving birth for the first time, add 20 weeks to this date;
- A girl who already has children must add 24 weeks to this date.
The method for determining the PDR by the first movements of the fetus is considered the least accurate.
If you had an irregular cycle before conception, be sure to warn your gynecologist about this. A very unpleasant situation happened to my friend during pregnancy. The fact is that her menstrual cycle is not 28, but 40 days. The doctors did not take this fact into account, and calculated the start date of the contractions, which turned out to be incorrect. As a result, the "X-day" came, and her labor activity did not begin.
The doctors already wanted to inject drugs for stimulation, but she managed to point out the error in the calculations in time. This is how useful it can be to independently calculate the time when the baby will be born! Thank God my friend and her baby are fine. The birth was easy, but she was scared in earnest. Now do you understand how important it is to correctly calculate the DA? Your health and the life of your newborn can depend on it.
Well, my dear future mothers! I wish you patience, calmness and good health. There is no need to be afraid of childbirth, and then it will pass quickly and easily. Perhaps you know of other methods for determining the date of birth of a child? Share them in the comments and be sure to visit our blog more often. Many more interesting and useful things are waiting for you.