How long does pregnancy last for women? Unfortunately, it is impossible to know the date of birth with absolute certainty. The date given by doctors is PDA - estimated date of birth.
There are cases when the actual date of birth coincides with the expected one. But all these cases are nothing more than mere coincidences.
Even if the woman knows exactly the day of conception and the date of ovulation, it is impossible to determine the speed of the sperm, how many days the egg moves along fallopian tubes when exactly it is implanted, how long it takes for the fetus to fully mature and when the baby is ready to be born.
Because everything Our bodies are individual, so in each case these processes proceed differently. Doctors use the average statistical standard, which is usually oriented towards.
So how many weeks does it last? normal pregnancy women? Scientists have calculated that in 80% of cases from the moment of fertilization to the onset of labor passes 266 days, respectively, this equals 38 weeks.
But the difficulty in this calculation is that, as a rule, expectant mothers do not know the exact day of conception.
The date of the last menstruation is remembered more accurately, so this date is taken as the basis for the calculation. Thus, it turns out that 40 weeks pass from the day of the start of menstruation to the birth. Therefore, to the question: how many weeks does pregnancy last, obstetricians answer - 40 weeks (280 days).
However, on the first day of the onset of menstruation real pregnancy has not yet happened, so the period calculated in this way is approximate. It is called menstrual or gestational age.
In fact, the fetus is about two weeks younger. This term is more accurate. It is called ovulation or fertilization. To more accurately determine the date of their birth, expectant mothers should calculate the date of their ovulation.
How to calculate the date of ovulation?
It's very hard to believe, but there is only one day in every month, when is it possible to get pregnant. In very rare cases, this day occurs twice during the month.
There is a simple formula that can be used without any tools. Scientists have found that Absolutely every woman ovulates 14 days before the start of her period.
If menstrual cycle lasts 28 days, it turns out that ovulation will occur on the 14th day after the last day of ovulation.
Agree, this calculation is very simple. However, there is one catch - This method is suitable only for those women who have regular cycle . In addition, you can only calculate the day of ovulation if you have an accurate cycle schedule for at least six months.
Moreover, in individual cases, ovulation may occur a little earlier or a little later. But, if we take the expected date as the starting point, then it turns out that the pregnancy actually lasts 266 days (280-14=266).
That is why doctors call a pregnancy that lasts from 266 to 294 days or from 38 to 42 weeks a normal full-term pregnancy.
When calculating, it is easy to notice that 280 days (40 weeks) are precisely 9 months.
However, obstetricians have their own month count. According to their calculations pregnancy lasts 10 months. The fact is that the so-called lunar months, which consist of 28 days, are taken into account. This is exactly the period the cycle lasts for most women.
Factors influencing the length of pregnancy
First of all, the duration of gestation is influenced by the state of health. expectant mother And other factors. For example:
- heredity;
- psychological condition;
- fetal development;
- intrauterine condition.
In case of prematurity, as well as due date, arise additional threats of adverse birth which may affect the health of the fetus and mother.
These phenomena may be caused by neuroendocrine disorders, previous diseases and previous abortions. According to statistics, women who have been treated for pregnancy are more likely to carry their fetus to term. A post-term pregnancy is considered to be one whose term has crossed the line 42 weeks.
Pregnancy too long
Causes
Many expectant mothers are more afraid of a premature pregnancy than a post-term pregnancy. However, in fact, post-term pregnancy is very dangerous.
Doctors still cannot give an exact answer as to what is the reason for too long a pregnancy. It is customary to highlight two factors of post-maturity - medical and psychological.
From a medical point of view, the cause of the problem lies in the woman’s physical unpreparedness for childbirth.
This can be explained the following factors:
- late cervical ripening;
- muscular disorders of the uterus and myometrium;
- slow fetal development;
- hormonal problems;
- endocrine and gynecological diseases of women;
- pathology of the uterus;
- heredity.
Moreover, The length of pregnancy also depends on the age of the mother. Most often overbearing during the first late pregnancy.
All reasons that can be attributed to the medical aspect identified through additional examinations. But the psychological side is quite difficult to identify.
It happens that psychologically the woman is not at all ready for childbirth. The reason for this is an unconscious fear of the birth process. A woman may fear pain or the possibility of losing the baby, slowing down the onset of the natural process.
At the first signs of post-maturity, you should consult a doctor. By performing an additional ultrasound, the specialist will be able to determine the condition of the placenta, amniotic fluid and, of course, the child.
When, after undergoing an ultrasound, V amniotic fluid traces of meconium are detected or problems with the baby’s heartbeat are detected, then, in this case, the doctor will definitely prescribe induction of labor or.
These appointments should never be refused, because the consequences of a post-term pregnancy can be disastrous.
Consequences
In 40% of cases, during late labor occurs placental dysfunction. Thus, she is unable to provide for the child required quantity nutrients and oxygen.
Often in post-term pregnancy, the fetus gains excess weight , which naturally complicates the birth process.
Also, in 20% of post-term babies there is a so-called "overmaturity syndrome", in which the skin changes.
There is too little subcutaneous fat in the child’s body, which stunts his growth. In addition, births that begin after 42 weeks have a higher incidence of birth injuries.
Most often this is expressed in Erb's palsy, fractures of the limbs and collarbones, as well as hip dysplasia.
IN in this case, the woman in labor is also exposed to additional risk, which is in the next moments:
- high probability;
- risk of uterine damage;
- prolonged labor;
- occurrence in the postpartum period.
No wonder this condition is called pathology of pregnancy. Therefore, to avoid such unpleasant consequences, you should consult a doctor.
However, we must not forget about the conventions of calculating the duration of pregnancy. As was said before, plus and minus are allowed in the duration of two weeks. There is no need to worry until 42 weeks.
Much more useful in last days pregnancy, prepare psychologically and physically for childbirth. During this period, expectant mothers need better quality rest.
Childbirth is a difficult process for any woman’s body, so it’s worth dedicating enough time to sleep. Many women attend specialized courses, where experts tell them how to survive childbirth better and safer.
Moreover, now on the Internet you can find a lot of auxiliary information that will make a woman more confident and eliminate unnecessary fear.
The main thing to remember is that after giving birth, you will meet your most beloved and closest person!
Every woman who has given birth at least once remembers pregnancy and childbirth throughout her life. And how interested she was to know when the pregnancy began, how many days and weeks a person’s pregnancy lasts, and, of course, the date of birth. And you, as an expectant mother, are also interested in learning about the timing of pregnancy. We will try to talk about this in our article.
There are certain methods of counting. Let's look at the most used of them.
Obstetric method. With the obstetric calculation method, which is considered the most universal and used by all gynecologists, during the initial appointment the doctor examines the woman manually, determines the size of the uterus, and determines the gestational age based on the measurements obtained.
According to gynecologists, the beginning of pregnancy is the first day of the last menstruation, from which the uterine lining prepares for pregnancy and the egg begins to mature.
In obstetrics, the duration of pregnancy is calculated at 280 days, that is, 40 weeks or 10 lunar months. It fits into 9 months if you use calendar months.
Using this method The expected date of birth (DAD) and the period of maternity leave are determined.
In the language of official medicine, PDR is the day, month and year of the birth of your baby. It should be remembered that the PDR is an approximate date. If we look at statistics, only 4 children out of 100 are born exactly on time.
In addition to the doctor, the woman herself can easily count the PDR. To do this, subtract 3 months from the first day of menstruation and add 7 days. For example, the beginning of the last menstruation is July 10, subtract three months and we get April 10. Add 7 days and we get April 17. This is the probable due date.
To obtain the PDR, you can refer to the table compiled by the date of the last menstruation. To do this, we will find in it the first day of the last menstruation, for example, January 11 (gray line), then in the white line we will see October 18 - the expected date of birth.
Read also:
Table for determining the maximum allowance:
The duration of pregnancy can be calculated using other methods.
Gestation period from conception. So, in the embryonic (true) period - from conception, the beginning of pregnancy is considered to be the first day of the last menstruation plus 2 weeks.
The basis for this calculation of the period is the possibility of ovulation (the release of an egg by the ovary) between 8 and 16 days of the menstrual cycle, and accordingly, the period when fertilization of the egg is possible can vary from 8 to 18 days.
Therefore, the duration of pregnancy using this method is calculated at 266 days or 38 weeks.
The considered timing values are typical for a normal pregnancy.
Norm or pathology
Normal pregnancy are called physiological adaptive changes in the body healthy woman during pregnancy without any complications.
Duration normal full-term pregnancy from fertilization to birth is from 38 to 42 weeks.
The duration of pregnancy may be different.
Premature birth
In some cases, the onset of labor occurs earlier than determined by nature. A completely healthy mother should not have a preterm birth (between 22 and 37 weeks). This usually happens for some reason.
So the reasons for the onset of premature birth can be:
- ARVI suffered during pregnancy; kidney diseases, diabetes, hypertension, heart defects and others;
- abortions and miscarriages;
- sexually transmitted infections;
- work involving heavy physical activity;
- emotional stress;
- alcohol, drug use and smoking;
- drug abuse.
Post-term pregnancy
The so-called due date is a very arbitrary concept. No doctor can say with certainty: “You will give birth on April 12.” He may answer that labor is most likely to begin between April 6 and April 16. However, there are often cases when April 16 is behind, and the woman is still awaiting birth. Since the rate of maturation is different for each child, fully mature children can be born on the 302nd day. Such a pregnancy is called prolonged (extended).
But there are often cases when the child is already ready for childbirth, but the uterus is not yet ready.
Such a pregnancy is called post-term and requires medical intervention.
In any case, if the pregnancy continues for more than 42 weeks, doctors assume a post-term pregnancy, the woman is asked to go for examination and is prescribed drugs that promote the development of labor activity.
Post-term pregnancy occurs in women due to:
- with irregular periods;
- diseases of the liver, stomach and intestinal tract;
- low mobility during pregnancy;
- with strong psychological stress (for example, studying at the institute).
Both states and premature birth, and post-term pregnancy can lead to an unfavorable outcome during childbirth, therefore, medical staff should monitor the condition of the mother and the unborn baby.
Trimesters of pregnancy
In obstetrics there is a concept “ trimesters of pregnancy” – these are periods lasting three months.
First trimester(from conception to 13 weeks) is the most difficult. At this stage, the body of the mother and the embryo gets used to each other and most of the difficulties and problems arise, for example, nausea, fatigue.
Second trimester(from 14 to 27 weeks) – a time of active growth and maturation of all systems of the unborn child. The mother feels this through weight gain and an enlarged abdomen. Your health improves significantly. In the middle of the trimester, the baby's first movements appear.
Third trimester(from 28 weeks to birth) – the finish line. This trimester is often the hardest physically. The woman's abdominal size increased significantly and she began to feel clumsy: difficulty walking, sleeping and sitting. But this is still the most joyful period. You have already walked most of the way. The birth of a new life is ahead.
You are now prepared. And you can confidently move forward to a wonderful event - the birth of your baby.
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04/25/2017 / Category: / Marie no comments
Every woman learns about pregnancy differently. Some people wait a long time for two lines on the test, while others accidentally find out about this during their next visit to the doctor. In any case, this news changes a lot in our understanding of the surrounding reality. Many questions immediately arise in your head, and one of the main thoughts is when is the baby due? On what day exactly will this wonderful event happen? How to correctly calculate the expected date of birth?
How many weeks does pregnancy last in women?
Despite the apparent simplicity of the question, there may be several answers to it, although the preliminary date of birth will be the same. How is it that the period in weeks is different, but the due date is the same? Let's try to figure it out.
Typically, from the moment of conception, pregnancy lasts 38 weeks. To be more precise - 266 days. As a rule, few people can say exactly on what day ovulation occurred and conception occurred. But almost everyone knows the date of the last menstruation, fortunately now every girl has an application on her phone, where an accurate count of all female physiological processes is kept. Therefore, this date is taken as the starting point.
It is known that ovulation occurs approximately 2 weeks after the start of menstruation. And to determine the gestational age based on the known date, just 2 weeks are added to this period of 38 weeks. Therefore, it is generally accepted that a normal pregnancy lasts 40 weeks or 280 days. And it is these 40 weeks that are counted from the date of the start of the last menstruation to calculate the date of birth! Let's divide 280 by 30 and get about 9 months, which everyone knows about.
You and I all understand that in the first 2 weeks, which is precisely the interval between menstruation and ovulation, there is no pregnancy yet. Therefore, weeks calculated in this way are called obstetric weeks. And the period of real pregnancy from the moment of conception in normal weeks is always 14 days less, exactly those 266 days that we talked about earlier.
But that's not all! 9 months – that’s what ordinary people, not doctors, are used to thinking. And in obstetrics and gynecology it is customary to say that pregnancy lasts 10 so-called lunar months. Why? It's simple. The duration of a girl's normal cycle is 28 days. Divide 280 by 28 days and get 10 months.
Your head is spinning, isn't it? But there is no need to panic. Everything was invented long ago before us. In order to find out the expected date of birth, you just need to use a calculator, of which there are a huge number on the Internet. You can enter into it either the date of the start of the last menstruation, or the date of expected ovulation, and you will receive the date of birth - in other words, the PDR. And the weeks will be counted in your antenatal clinic.
Is the traffic date correct?
Why do movies so often show how the onset of labor takes a woman by surprise, and how someone gives birth without ever reaching the hospital? After all, if you know the exact date, you can prepare in advance? All this is true.
But, firstly, no one can say for sure on what day ovulation occurred, when the egg was fertilized, so the calculations exact date Pregnancies are very conditional. Secondly, the duration of pregnancy depends on many factors: the health of the mother, her mental state, heredity, baby development and so on. Therefore, it is generally accepted that a normal pregnancy lasts from 38 to 42 weeks: plus or minus 2 weeks from 40.
As you can see, the difference in amount is about a month. There is nothing to worry about if you listen to your own condition and visit on time antenatal clinic, undergo all necessary examinations. This means that doctors are constantly monitoring your condition, and you will be ready for labor whenever it begins.
Does gestational age depend on the sex of the child?
It is believed that pregnancy with a girl is shorter than pregnancy with a boy. And that mothers of boys usually go beyond the period of PPD by at least 1 week. But scientific confirmation of this folk beliefs(and there is no other way to call them) no: according to statistics, the number of boys born at 38 weeks is equal to the number of girls born at 42 weeks.
There is also no scientific confirmation of the talk that the first pregnancy lasts longer than the second or third. Perhaps each subsequent birth is easier than the previous one, but exactly how long each pregnancy will last does not depend in any way on the number of children the woman has. Therefore, try not to get hung up on what gender of child you are expecting or what type of pregnancy this is. This is not so important; it is better for your baby to know when to be born.
IMPORTANT! The length of pregnancy does not depend on the gender of the child or the number of children already born. Everything depends only on the body of the expectant mother. The most important thing that she can and should do is to lead a healthy lifestyle, eat well, worry less, worry less and get as many positive emotions as possible. And then the baby will develop correctly, be born on time and healthy!
Have a good pregnancy and easy birth!
Despite sometimes poor health during pregnancy and various ailments, women remember this time as happy. Every mother is waiting for a miracle - the birth of her baby, and her desire to correctly and accurately calculate the day of birth is quite understandable. But, as in every business, there are some subtleties here.
It is unlikely that anyone will be able to determine the exact date of birth, and even with one hundred percent certainty. It is quite possible that you will calculate as much as possible, but when this exciting moment actually happens, no one can say for sure.
There are indeed many determining factors, but none of them will be a priority. You can know exactly the date of ovulation and even conception, but no one can predict how the sperm will behave, how long the egg will travel through the fallopian tubes, again it is unknown when it is implanted, the period for the full development of the fetus in the womb, and the time when the child will be ready to be born.
In all cases, these processes are purely individual. But doctors have nevertheless identified a “gold standard” that can presumably be followed. According to their opinion and calculations, in most cases, 38 weeks or 266 days pass from the moment of fertilization until the onset of birth itself. But there are pitfalls here too.
The thing is that most women do not know for sure this day of conception or ovulation. But what all women probably remember is the date of their last menstruation. Naturally, it is precisely this that is taken as the basis for calculations. As gynecologists say, 40 weeks or 280 days pass from the 1st day of the last menstruation until the birth itself.
But since there is no real pregnancy on the first day of menstruation, the period calculated in this way is called menstrual (or gestational). The fetus, in fact, is about 2 weeks younger. This period is called ovulation or fertilization. Ovulation on average occurs on the 14th day after the end of menstruation. If we take this date as a starting point, then yes, the duration of pregnancy is 280-14 = 266 days. But we repeat, all this is purely individual. Some women ovulate a little earlier, while others ovulate late.
Therefore, a normal full-term pregnancy in obstetrics is considered to last approximately 266-294 days, it turns out 280 days +/- 14 or 38-42 weeks. However, recently these borders have been extended to 37-43 weeks. If we convert 280 days or 40 weeks into months, then this is 9 months, as it should be, according to popular calculations.
In obstetrics, they say that the duration of pregnancy is 10 months - these are the so-called lunar months, the duration of which is 28 days. This is exactly the cycle, if we take the cycle of the average woman as a basis. It is necessary to take into account errors in the described calculations if your periods are characterized by instability or when there is an increase/decrease in the 28-day cycle.
Objective factors also help the doctor determine the due date: and other signs. Often, to determine the due date, they resort to the Naegele formula, in which 9 months and 7 days are added to the date of the 1st day of your last menstruation. Following the simplified method, subtract 3 months from the 1st day of the last menstruation and add 7 to the resulting number.
Note that the 280-day period (which is 40 weeks) is based on a 28-day menstrual cycle with ovulation expected on day 14. Of course, you cannot discount the state of your health, condition and intrauterine development fetus, naturally your psychological mood - the duration of bearing a child will depend on these factors.
Many people know of cases when women gave birth on the very day they set for themselves: either for their birth, or for their husband’s return from a business trip, or for a specific holiday. The conclusion is that all calculations are very conditional. Pros or cons are allowed, at least two weeks.
Therefore, you may miss the deadline if you decide to conceive a baby on a certain day. Regarding your doubts about whether you are overbearing or whether you will give birth on time, be guided by your health, your own feelings, the behavior of the fetus and, of course, medical indicators and the conclusion of your attending physician.
Let's find out for ourselves when a pregnancy is considered post-term? This is a pregnancy that lasts more than 42 weeks. It occurs mainly in primigravidas, whose age is less than or greater than the average childbearing age. Also included here are women who have had 5 or more pregnancies. Here there is a hereditary factor as a cause, and various pathologies, fetal growth retardation is intrauterine.
If labor is not observed at the expected time, this is an unfavorable factor. After 40 weeks of pregnancy, if we rely on the normal course, fetal growth slows down and practically stops at 42 weeks. Therefore, to stimulate labor, the expectant mother is advised to move more; sometimes special gels are used that are injected into the cervix and which stimulate labor.
Premature births are those that occur before 37 weeks. In these cases, premature children are born with a body weight of 2500 grams and a height of less than 45 cm. They differ from normally born children in the immaturity of their organs and systems and poor resistance to the environment. Today, modern maternity hospitals care for babies born after 28 weeks of gestation and weighing more than 500 grams.
Remember - the pregnancy period is unforgettable, no matter how long your pregnancy lasts. Relax and enjoy it, and then the birth will be safe and easy, and your baby will be healthy and strong!
Having learned that she is pregnant, every woman immediately begins to wonder how many weeks the pregnancy lasts and when she will be able to hold her baby in her arms. Unfortunately, no one can establish the exact day and hour of his birth. It is possible that your calculations or those of the obstetrician will be correct, but this will be more luck than a rule.
The main obstacle to knowing the duration of pregnancy of a particular patient is that it is not possible to determine the exact day of conception or fertilization. As well as finding out at what speed the sperm will “chase” the egg when it fertilizes it, and in the uterus it will make itself felt by its growth and development. To study this process, a lot of time must be allocated for each pregnant woman. So the obstetricians developed a certain “ golden mean» how many weeks a normal pregnancy lasts.
Scientists have found that in most cases, approximately 70-80%, 38 weeks or 266 days pass from fertilization to the moment the pregnancy begins. This is where difficulties arose, since almost all women do not know the day when they conceived or ovulated. The only thing that comes to mind about this is when their last period started. So it was decided that this particular date would be the starting point for calculating the duration of pregnancy in women. According to this theory, the gestation period lasts 280 days or 40 weeks.
However, this method also has a correction: since with the onset of menstruation there can be no talk of any pregnancy at all, it was decided to call the period obtained in this way menstrual, since the age of the fetus is at least 2 weeks less than what was calculated.
How to calculate the duration of pregnancy?
Usually the moment of ovulation occurs two weeks after the end of menstruation. So it turns out that from the accepted 280 days you need to subtract these 14, during which conception is simply impossible. So it turns out that gestation lasts 266 days. Again, you should not lose sight of the individuality of each woman, thanks to which it can come earlier or later.
That is why the duration of pregnancy in women, which proceeds normally, ranges from 32 to 34 weeks. Although recently these limits have shifted somewhat and acquired the meaning of 37-43 weeks. So it turns out that all mathematical calculations are purely approximate and cannot specify the date of birth of the child.
What can affect the change in the length of pregnancy in weeks?
For the duration of the course " interesting situation» the following factors may influence:
If you are constantly plagued by problems regarding how much obstetric weeks The pregnancy lasts, and whether you deliver the baby on time, you shouldn’t do your own calculations and worry your psyche even more. This event does not depend on you, but is completely determined by ongoing natural processes. During the middle period of pregnancy, you should enjoy your new position, listen to the baby's movements and follow the doctor's instructions. This will guarantee that the baby will appear at the right time.
