Set gestational age by last menstrual calculator. Determining the duration of pregnancy
Many women keep menstrual cycle calendars. It is more convenient to plan trips, vacations, visits to the gynecologist. Yes, and keeping in mind significant dates for a woman is simply inconvenient. Modern representatives of the weaker sex today plan their lives, and the appearance of children too. Therefore, the date of the last menstruation will help to more accurately navigate when exactly the baby will be born, and will help to accurately determine the gestational age. So, let's learn more about such calculations.
About obstetric pregnancy
On average, women carry children for 280 days, which are calculated from the first day of the last menstruation. This period is called the obstetric period. It is on it that the definition of a woman's prenatal leave and the preliminary date of birth are based. The obstetric period is also a kind of comparison scale that is used to evaluate the fetus based on the results of the first ultrasound. How exactly do doctors in the antenatal clinic calculate the preliminary date of birth based on the last menstruation? They “rewind” 3 months from the first day of the last menstruation and add 7 days. This date is the probable due date. So, let's give an example of such a calculation. The last menstruation of the expectant mother was on March 15. This means that the preliminary council of childbirth is scheduled for December 22. But, as practice shows, very rarely a child is born on this very day. After all, everyone is well aware that many factors affect the course of pregnancy, including genetics. Therefore, childbirth can occur earlier than the period determined by the doctor, and a little later. Usually the first birth occurs earlier.
As for the gestational age, it is also recognized with a focus on the last menstruation. If she was on March 15, then approximately on the 12-14th day the woman ovulated, her egg was fertilized. So, the gestation period begins on March 29. And if the patient goes to the antenatal clinic on May 10, then her pregnancy is approximately 6 weeks. Again, we are talking about an approximate period, because in some women ovulation occurs 11 days after the start of menstruation, in others - 15, which depends on the length of the cycle. In addition, on the first day of ovulation, conception may not occur. Some spermatozoa can "work" for 3-7 days. A fertilized egg, moreover, needs time to move to the uterus and attach to its walls.
About embryonic gestation
So, you have determined the obstetric period for the last menstruation. But the doctor sometimes stuns you by the fact that this period does not coincide with the real, that is, embryonic. It is determined by the results of an ultrasound examination. The difference may be a week or two. Such discrepancies sometimes make the expectant mother very worried, poison her life. After all, the pregnant woman thinks that the baby is not all right. Women whose gestational age according to ultrasound is more or less than monthly, are afraid of abnormalities in the development of the fetus, as well as miscarriage. But we must understand that it is very difficult to read ultrasound. Even experienced doctors can make mistakes in their assessments, and each baby develops individually. And if, after such a study, a woman is told that the head of the fetus is developed for 22 weeks, and the legs for 24, then the anxiety of the pregnant woman can be understood. In such situations, you can go to another doctor and do a second ultrasound. Sometimes old ultrasound diagnostic devices show an indefinite picture of the development of the baby.
Practice shows that the gestational age is determined more accurately up to 12 weeks, since during this period the embryo develops evenly, and the stages of its development are obvious. The length, coccygeal-parietal size of the fetus, the development of individual organs are precisely determined. But after this period, each child develops individually. One may lag behind in its development for a variety of reasons, while the other, like a leader, is ahead of the classical time. Specialists are guided by tables of development parameters. And if, after an ultrasound, the embryonic gestational age does not coincide with the obstetric one, do not panic. It happens, and it's quite normal. As well as the fact that a pregnant woman asks a lot of questions to the observing gynecologist about this.
After all, the definition of this period will help to calculate the approximate date when the long-awaited child will be born. There are a lot of methods, and it's hard to say which one is the most accurate. But it is quite possible to determine which week of pregnancy you are on your own at home.
Methods of medical examination
Consider how doctors determine the duration of pregnancy:
- By ultrasound. This is one of the most common ways. The doctor measures the size of the fetus, and according to them, he already calls approximately your term.
- By the date of the last menstruation. This way you can determine when ovulation occurred.
- According to the size of the uterus. With each week of pregnancy, the uterus changes, increases in size and rises higher.
- HCG analysis. It shows the amount of hormones in the blood. The method is quite accurate, but still does not give an unambiguous result.
Pregnancy: how to determine its term at home
Some women prefer not to go to the doctors right away because they know how to find out early pregnancy at home. There are many methods, here are some of them:
- By ovulation date.
- For the last menses.
- By the movement of the baby.
- By date of conception.
- Negele formula.
Determination of pregnancy at home in the early stages
If you don’t have a test on hand, then there are other ways to find out early pregnancy at home:
- With baking soda.
Take a small container, fill it with morning urine. Add a spoonful of soda there and carefully watch what happens. If the baking soda reacts and starts to sizzle, then you are not pregnant. And if it precipitates, then you will soon become a mother.
- With the help of iodine.
You will need a container filled with morning urine. Add a small drop of iodine to it. In the event that the drop remains on the surface, then you are pregnant, and if it dissolves, then no.
Ovulation: how to determine the gestational age by it
Ovulation is the period of the menstrual cycle when a woman can become pregnant. At this time, the egg matures, then goes into the fallopian tube and stays there for a certain period of time in order to wait for the sperm.
If you want to understand how to find out the gestational age by the date of ovulation, then you should have a schedule for maintaining basal body temperature. By the way, in pharmacies you can find tests that help to accurately determine ovulation. If sexual intercourse occurred during this period, then most likely you are pregnant.
We determine the period by the last menstruation
Finding out the gestational age by the last menstruation is another way that you can use at home, without the help of doctors. The first day of the last menstrual cycle is the period when the egg matures, the body is completely rebuilt and conception is at the moment as possible as possible.
Finding out the gestational age by the last menstruation is very simple. Count how many weeks have passed from this date to the present moment - that's all.
Take a calendar and add 280 days to this date. This is approximately 40 weeks (how long the pregnancy itself lasts). It will turn out an approximate time, you must give birth to your child.
It is easiest to find out the gestational age by the last menstruation. It is for this reason that women use it at home. Not everyone can measure their basal temperature and determine the period of ovulation, but everyone records the start date of menstruation.
When the baby moves in the womb
Any representative of the fair sex, who is preparing for the role of a mother, is very sensitive to the period of bearing a baby. There are many questions that relate to pregnancy and childbirth. Someone is trying to find out the gestational age by menstruation, someone uses other methods.
It should be noted that it is almost impossible to determine the exact date. But, if you count it in several ways, then the probability will increase. For example, you have already calculated the period for menstruation, now wait until you feel the first movement of the baby.
In primiparous women, this usually occurs at 20 weeks, in multiparous women, it may be earlier. In any case, when you feel that the baby in the womb has begun to move, you will know that you are now about 20 weeks pregnant.
Date of conception: how to use it to calculate the gestational age
It is only possible to determine which week of pregnancy you are currently in if you know exactly the date when the conception occurred. Otherwise, only a gynecologist can do this.
To find out the gestational age by weeks and days, sign up for an examination, the doctor will find out from you the date of the first day of the last menstruation and calculate the obstetric period, name the approximate date of birth. Do not forget that this is only an approximate date. Only your child knows when he will be born. It is possible to find out the gestational age by weeks and days quite accurately, but you should not rely on the date of birth.
Negele formula
The Negele formula is the easiest way to find out the approximate due date.
- Take the first day of your last period and subtract three months from it.
- 7 days are added to the resulting date.
- The final date is the approximate time when the baby will be born.
Exact gestational age - is it realistic to know
Most women are interested in the question of how to find out the exact gestational age. It is problematic to do this at home, because any method gives deviations from the truth. If you want to get more reliable information, then you can do this in the following ways:
- Ultrasonography.
The exact time of ultrasound can show only in the early stages. The fact is that embryos develop equally only in the first 3-4 weeks after conception has occurred. Further, the embryo in each girl develops differently.
- Gynecological examination.
How to find out the exact gestational age at a gynecological examination? The doctor measures the uterus, sometimes even determines the position of the fetus at this stage. Based on the resulting data, you can understand what week of pregnancy a woman is in, because the uterus is constantly changing and there are standards for how this should happen.
Boy or girl
An ultrasound examination is not yet to be done, and the expectant mother is already overwhelmed with interest, whom will she give birth to - a boy or a girl? It is worth noting that ultrasound sometimes fails to determine the sex of the child. Some parents are happy about this because they want a surprise, while others, on the contrary, are eager to know everything at once.
You can find out the sex of the baby in early pregnancy in the following ways:
- According to the intensity of sexual activity.
If the conception of a child occurred at a time when the couple was sexually active, then it is more likely that a boy will be born. The fact is that mobile "male" spermatozoa do not live very long. Therefore, when a man rarely has sexual intercourse, then in the body there is a greater vitality of "female" spermatozoa. This has been scientifically proven.
- Purity of blood.
The sex of a child is very often determined depending on which of the spouses has newer blood. It is believed that in women the blood is renewed once every 3 years, and in men once every 4 years. If for the period when the conception occurred, the man's blood is newer, then there will be a boy, if the woman has a girl.
- According to the formula.
Our grandparents very often used the formula to determine the gender of their unborn child. It looks like this: 49-X+1+Y+3. Y is the month of conception and X is the age of the father. Substitute all the data and calculate what happens. If the number is odd, then the probability that a girl will be born is higher, and if it is even, a boy.
- By woman.
They say that if a woman gets prettier during pregnancy, then she is expecting a boy, because boys take care of their mother and give her beauty. With girls, the situation is the opposite, they take away beauty. Therefore, if you notice that your hair has become less frequent, your nails are exfoliating, your skin is dry - this means that, most likely, you will give birth to the fair sex.
Which method is the most accurate
Every woman is interested in how to find out the gestational age, and at least the approximate date when she will give birth. All of the above methods are good in their own way, but none of them can give you a clear answer to this question.
The fact is that each representative of the fair sex is special, like her body, and when the baby decides that he is ready to be born, only he knows. This can happen a few weeks earlier if the fruit is ripe. If the baby is not yet ready to leave the womb, then the pregnancy is delayed for another few weeks.
Now you know how to find out the gestational age at home, as doctors do. Moreover, in the event that the ultrasound does not show the sex of the child, then thanks to the methods listed above, you can determine this yourself. Even if the result is unreliable - it's still interesting. After the baby is born, you can determine which method turned out to be true for you.
Our online pregnancy calculator will help you calculate your pregnancy by week. Pregnancy is an amazing period in the life of any woman, when a new life appears and develops inside. This is happening at a fairly fast pace. In 9 months, the fetus goes through stages of development from a few small cells to an organized organism. With each week of pregnancy, the little one undergoes certain changes, improves existing systems, acquiring new qualities. Therefore, it is very interesting for the expectant mother to find out during the whole interesting situation what is new with the baby, what he is like, what he can do at this stage. Description next.How to calculate the gestational age by week
For this, an interactive Pregnancy Calculator is intended, which allows you to calculate a woman's pregnancy by weeks, thus finding out the approximate date of birth of the child. The calculation is carried out from the first day of the last menstruation, although it is more correct to consider the term of conception from ovulation. Although the exact time of ovulation is not always known, the pregnancy calculator reflects the timing for the more common cycle of 28 days. With a long or short cycle, amendments are possible, although in practice it is customary to calculate the gestational age of a woman by menstruation. This Pregnancy Calendar is designed to calculate the timing of key moments in fetal development and includes a birth calculator.What is gestational age and how is it calculated? It is customary to single out obstetric and embryonic terms, and many mothers simply get confused in these terms, and today we will try to figure it out.
The first thing we will start with is the obstetric term, because in fact, our gynecologist will make all calculations based on the obstetric term.
obstetric term
The obstetric period is calculated from the first day of the last menstruation, so when you go to the gynecologist for the first time, clearly know the date of your last menstruation, this will make your life easier, and in the future all of your data will be entered in a special card, everything will be written there.
The obstetric period involves 280 days of pregnancy, well, these are averages, it is clear that each mother is an individual and this period may vary, but it is customary to consider 280 days.
According to the obstetric period, they issue directions for tests, a certificate of maternity leave and all other documents that you will need in the future, the same exchange card, where all the data will be put on the basis of the obstetric period.
And according to the obstetric term, the estimated date of birth is calculated, this is the PDR.
How to calculate the expected due date
The first day of the last menstruation, 3 months ago and 7 days are added, so you can calculate your gestational age and when your baby will be born.Embryonic term
It is calculated from the moment of conception and is usually shorter by 14-15 days of the obstetric period.
That is, in fact, we all know biology, menstruation has passed and a new cycle of egg formation has begun, and on day 14-15, on average, it matures and is ready for fertilization, this is called the day of ovulation.
In fact, it will be very difficult for us to determine and calculate the exact day of ovulation, of course there are different tests in the pharmacy, you can buy and know exactly when you ovulate,
but in principle it is very difficult to determine or calculate, because fertilization itself occurs on the day of ovulation, plus or minus 3-5 days.
An interactive pregnancy calculator is a convenient service for calculating the date of birth and determining all significant stages of gestation. If the expectant mother knows the date of conception for sure, then you can enter it into the form of an interactive calendar and get the desired result. When this date is unknown, then the 1st day of the last menstruation can be taken as a basis. The service works very quickly, so in just a few seconds a woman will be able to get the information she needs. Now the expectant mother will know for sure when the baby will begin to respond to touch, when it will move for the first time and other important points.
If a woman suspects that pregnancy has occurred earlier or later than the onset of menstruation, then after undergoing a planned ultrasound, the necessary calculation can be made again. At the same time, the date of conception will now be as reliable as possible, since the doctor will determine it based on medical indicators. The pregnancy calculator is an interactive assistant that allows you to find answers to many questions.
Among the benefits of using a pregnancy calculator are the following factors:
After a woman finds out about her situation, she has many questions. She is interested in how long the stomach begins to increase in size, when it is necessary to undergo an ultrasound scan, when the baby is born, when you can feel the first movements of the crumbs, etc. Answers to these and many other questions can be found using the pregnancy calculator.
The calculator allows you to determine the exact terms of the trimesters of pregnancy, find out such important dates as the day of the expected birth, conception, and maternity leave.
A woman will know what signs of a developing pregnancy she needs to pay attention to, and what to ask the doctor during a scheduled visit.
The calendar will inform the woman about when and what tests she will need to take, when to undergo an ultrasound scan. The online pregnancy calculator is a kind of reminder that is always at hand.
Pregnancy period - what is it?
After ovulation, when the egg is released from the ovary, it lives for 24 hours. This time is considered the most favorable for conceiving a child. When the cycle equates to 28 days, ovulation occurs on the 14th day from the start of menstruation. The sperm meets the egg, fertilizes it, and a week later the embryo attaches to the inner lining of the uterine wall.
It is sometimes impossible to calculate the exact date of ovulation and conception. Therefore, doctors take the 1st day of the last menstruation as the beginning of pregnancy, and exactly 280 days later, delivery should occur. As a result, a paradox arises: the period began to be counted when the pregnancy itself had not yet taken place. Therefore, it should be understood that the embryo exists approximately 14 days before the date set.
The following methods are available to determine the gestational age and due date:
Passage of ultrasound.
Using the Negele formula.
Determining the level of hCG.
Measurement of the uterus during examination in the office of a gynecologist.
Evaluation of one's own sensations (according to fetal movements).
Obstetricians to determine the gestational age are guided by the data of an ultrasound examination. You can clarify them with the help of a gynecological examination of the uterus, as well as knowing the date of the last menstruation.
ultrasound
Ultrasound is the basic method for determining the gestational age. You can count on maximum reliability only when the procedure is carried out after 10-12 weeks from the moment of fertilization. In the future, an ultrasound examination will not allow you to accurately determine the gestational age and the date of the expected birth. Therefore, it is so important to undergo an ultrasound scan in the 1st trimester of pregnancy.
The devices used by diagnosticians allow fixing a three-week-old fetal egg. The date of conception and the date of the expected birth of the doctor is calculated based on an assessment of the coccyx-parietal size of the embryo. This indicator can be determined after it reaches 3 cm or more. According to the results of the ultrasound, the doctor issues a conclusion. It indicates the embryonic and obstetric gestational age. The first characterizes it from the moment of conception, and the second - from the day the last menstruation began.
When the fetus reaches 22 weeks, it will not be possible to accurately determine its age. However, at this time, doctors evaluate the main criteria for the intrauterine development of the child. The size of the head, the circumference of the abdomen, the length of his femur are measured. If the indicators of the fetus do not correspond to its age, then intrauterine growth retardation can be suspected.
It should be understood that there are individual characteristics that the baby inherits, for example, short stature or a large head circumference. They appear in the third trimester, so it will no longer be possible to calculate the gestational age by ultrasound.
Determination of gestational age by the date of the last menstruation
If a woman's cycle is equal to 28 days, then it is not difficult for her to independently calculate the date of birth. To do this, you need to use the Negele formula:
"PDMP (first day of last menstruation) - 3 months + 7 days = EDD (estimated date of birth)"
Calculation example: PDMP was on August 16, which means August 16 - 3 months + 7 days = May 23. On this day, the birth will take place. In this way, everyone calculates the date of birth.
Cases when it is not possible to determine the gestational age by menstruation:
The menstrual cycle is irregular or too long. If it exceeds 35 days, then ovulation will not occur on day 14, so it is impossible to calculate the exact date of birth using the Negele formula.
If there is a risk of miscarriage in early pregnancy. The main sign of a threat is often the appearance of scanty spotting. A woman can confuse them with menstrual bleeding, and will not even guess that she is in position. In this case, ultrasound can help in determining the duration of pregnancy.
If the woman is taking contraceptives. When the regularity of the scheme is broken, there is a chance to become pregnant. Ovulation in this case happens suddenly, so it is impossible to calculate the exact date of its onset.
Examination of a woman on a gynecological chair
Every woman must be examined by a gynecologist before being registered.
It defines options such as:
The height of the bottom of the uterus;
The size of the uterus.
These indicators allow us to assume the gestational age, if not exact, then indicative. The error in the definition is due to the individual characteristics of the location of the uterus. In addition, a full bladder and the presence of fibroids can make examination difficult. In the event that a woman is carrying 2 or 3 babies, the uterus will be enlarged more than usual, which will also affect the accuracy of timing.
Determining the duration of pregnancy by the level of hCG
8-10 days after the conception has occurred, the level of chorionic gonadotropin (pregnancy hormone) begins to rise in the woman's body. This figure will double every day.
It should be understood that it is impossible to determine the gestational age by the level of hCG with 100% accuracy. The fact is that the boundaries of its norm for each week of pregnancy vary quite widely. Moreover, the hCG indicator can go off scale when carrying twins or triplets, as well as with various pathologies of pregnancy.
As practice shows, a woman begins to feel the first movements from. This pattern is valid for those expectant mothers who give birth for the first time.
If the birth is the second or more, then the woman can already feel the movements of the baby on -.
It is impossible to determine the gestational age for this indicator by 100%. Sensitivity will be influenced by such factors as the thickness of the layer of fat between the uterus and the peritoneum, the individual characteristics of the fetus, etc. In addition, when a woman really wants to feel life inside herself, she can even take the passage of gases through the intestines for the movements of the fetus.
How to calculate the gestational age after IVF?
Many expectant mothers have questions about the reliability of calculations of the gestational age after artificial insemination, because an already developing embryo is placed in the uterine cavity.
Gynecologists calculate the gestational age, starting from 1 day of the last menstruation, and it does not matter in what way the conception was carried out. However, there is an exception to this rule: with IVF with a protocol for suppressing menstruation, 14 days are added by the day of embryo transfer, and only from this date the countdown of the gestational age begins.
Why do you need to know the exact gestational age?
The gestational age is an important indicator that acts as a guide for doctors in the following points:
Determination of the date of birth of the child;
Assessment of the development of the fetal body;
Planning for prenatal screening for chromosomal abnormalities;
Assessment of the child's ability to survive outside the womb in the event of his early birth.
Knowing the gestational age will allow a woman to psychologically prepare for the date of the upcoming birth, and will also provide information about what happens to the baby in one or another period of its intrauterine life.
Use our EDD (Estimated Due Date) calculator to calculate your baby's estimated due date. The calculation can be made by the date of conception, or by the date of the last menstruation. Select the appropriate option and enter the original date. As a result of the calculation, you will receive the cherished date, as well as an accurate pregnancy calendar with comprehensive information about the development of the fetus and medical indications for each week. Calculation results can be saved to email or printed.
EDD Calculator - Estimated Date of Delivery
with pregnancy calendar
