How to determine the gestational age by the last monthly


There are many different signs of pregnancy for a girl. The most common of these are the change in taste preferences, mood swings and painful toxemia.

The desire to know the sex of a child is a natural need of almost all parents. Often, future mothers dream of girls, choosing a name and imagining how they will dress up their baby. The fair sex begin to look for any information to try to determine the pregnancy of the girl in the early stages. Can you believe various signs, if you want to know who will be born?

External signs

There is an opinion that the appearance of the future mother during a pregnancy with a girl varies considerably. People say that the daughter takes beauty, therefore the condition of hair and skin worsens. Some develop pigmentation, peeling and dryness. Severe swelling of the ankles can be a sign that a girl is expected. During the pregnancy, the girl’s belly becomes round and large, the waist disappears, the sides are noticeable from the back.

The form of the abdomen during pregnancy girl looks like a melon. Rounded outlines visually merge with the body, not strongly protruding forward. Although the sign can be useful at a later date, since at least 24 weeks should pass from the moment of conception to determine the form.

Scientific methods

According to the doctors, there is no difference in pregnancy with the girl. Mothers of many children who have given birth to heterosexual children confirm that popular signs are often mistaken. If half of them predicted the right gender, then all the same 50/50 percent of the probability remains, as without them. You can most accurately determine the gender using:

  1. Ultrasound
  2. Blood test
  3. Analysis of amniotic fluid

If the first method is completely safe and accessible to everyone, blood and amniotic fluid tests are usually prescribed when indicated by the doctor. Despite the fact that they make it possible to determine the sex at an earlier date, such tests carry certain risks and are not done in every clinic.

Signs of pregnancy as a girl should not be regarded as a serious prognosis, but this is a great opportunity to monitor changes in the body. Attempts to predict gender with the help of various signs may not succeed, but they are able to cheer up not only future parents, but also their surroundings.

Obstetric term

In medical practice, it is customary to calculate the duration of this pregnancy by the date of the last menstruation (PDM). The starting point of menstruation is taken as a reference point - the very moment when regular bleeding began. Then you should arm yourself with a pocket calendar and make simple calculations:

  • Last menstruation date minus 3 months plus 7 days = estimated delivery date.

For example, the last menstruation took place on March 15th. Subtract from this date exactly 3 months, and we get December 15th. We add 7 days, and we receive on December 22 - estimated date of delivery. It is on this date that the 41st week falls - the time when a child should be born according to all forecasts.

It is important to know that nature does not care about our calculations. A baby can be born at any interval from 37 to 41 weeks, and this will be perfectly normal. Calculated birth date is only a guideline. The future mother needs to prepare for a meeting with her baby during this period, but assume that the child can be born much earlier.

Calculate the gestational age at the moment is also not difficult. We find on the calendar the day of the last menstruation and count from it complete and incomplete weeks to the current date. In our example, it will look like this:

  • PDM - March 15
  • The current date is April 25th.

In 2016, March 15 falls on Tuesday. A week later, next Tuesday, March 22, obstetric gestational age will be 1 obstetric week. And on April 25, the gestation period will be 5 weeks and 6 days. It is necessary to remember the day of the week on which the last menstruation began, in order to be guided further by this parameter.

Obstetric gestational pregnancy does not accidentally imply a start from the date of the last menstruation. Usually, a woman at least tentatively knows when this event occurred, and there is no confusion with the definition of dates. That's just in fact it turns out that in 1 and 2 obstetric week of pregnancy as such is not yet. At this time, the woman's body is still preparing for the upcoming conception, producing the necessary hormones and rebuilding to the desired rhythm.

Fetal term

Fetal or true gestation is quite difficult to calculate. For this you need to know exactly when the conception of the child occurred. It is not difficult to find out this date, if the intimacy with the spouse was only once a month or the pregnancy occurred after IVF. But what if a woman does not even suggest in which of the days of the month could a new life arise?

With a normal 28-day menstrual cycle, ovulation (maturation and release of the egg) occurs at 12-14 days. It is during this period, the highest probability of conceiving a child. Thus, fertilization usually occurs 2 weeks after PDM. As a result, the embryonic period of pregnancy differs from obstetric just by the indicated 2 weeks.

Far from all women menstruation comes regularly after 28 days. Normally, the length of the menstrual cycle can be from 21 to 35 days. With this variation, it is much more difficult to determine the day of ovulation and the date of the alleged conception. If, prior to pregnancy, a woman daily monitored basal temperature and kept a schedule, she could track ovulation on time and plan for the onset of pregnancy. In other situations, you will have to focus on obstetric gestational age.

Possible mistakes

There are situations in which the duration of pregnancy can be determined incorrectly:

    Irregular menstrual cycle. If a woman's menstruation each time comes at a different time, it will be quite difficult to calculate the duration of pregnancy. In this scenario, the first phase of the cycle is extended, and ovulation occurs at a completely unexpected time. As a result, the difference between obstetric and embryonic gestational age can be more than 3 weeks.

Certain difficulties arise when calculating the duration of pregnancy in lactating mothers. Often the conception of the child occurs before the arrival of the first menstruation after childbirth. In this case, additional methods of research come to the rescue, suggesting the duration of pregnancy and the expected date of delivery. Miscarriage. Regular menstruation is not always what it seems. Uterine bleeding may be a sign of a miscarriage that began at 4-5 weeks. As a rule, such menstruation is more abundant and painful than usual. It is possible and the opposite situation, when the monthly come rather scarce. Most often, menstruation passes with a slight delay of 2-4 days. Women blamed such a situation for stress or overwork, even not knowing about the pregnancy that had occurred several weeks ago.

A miscarriage that does not always lead to the death of the embryo. In some cases, the bleeding stops, and the baby continues to develop safely. After 3-4 weeks, without waiting for the next menstruation, the expectant mother makes a pregnancy test - and learns about her changed situation. That's just the term of this pregnancy is about 8 weeks, which is easily found out during an ultrasound or when examined by a gynecologist.

The following methods help to determine the duration of pregnancy in difficult situations:

  1. Determination of hCG level. Chorionic gonadotropin is doubled every 48 hours during a normally developing pregnancy. Having passed a blood test to determine this hormone, we can tentatively assume the period of gestation. It should be remembered that when threatened with a miscarriage or a regressing pregnancy, hCG will be below normal.
  2. Examination by a gynecologist. During a bimanual examination, an experienced doctor can estimate the size of the uterus and compare them with the duration of this pregnancy. The method is ineffective when carrying twins, because in this case the uterus will be much more than the norm.
  3. Ultrasound. Already for a period of 4-6 weeks, an ultrasound can accurately determine the size of the fetus and the duration of this pregnancy. The more modern the ultrasound machine, the higher the diagnostic accuracy and the lower the probability of errors.

What happens at 33 weeks gestation?

The movements of the fetus at the thirty-third week of pregnancy are so constrained that you will not notice any flip-flops, but sometimes you will feel tangible movements of the limbs. Baby shocks in the area of ​​the liver, stomach, bladder can be very painful, but, as a rule, they are not capable of causing harm to the mother's body. Now you can clearly distinguish the little bully's butts with your hands and feet and even reassure him with a gentle stroking. Usually, fetal movements become most active when you are resting, and decrease while walking.

Keep on listening to the pace of stirring. In case of a pronounced deviation from the habitual behavior of the fetus, it is not necessary to immediately sound the alarm, but one should go and see the doctor without delay and report on the observations. Most likely, you will be assigned an additional ultrasound of the fetus or examine the child's heartbeat with a stethoscope in order to make sure that everything is in order. Many future mothers are mistaken, believing that abdominal movements should be equally noticeable in all pregnant women and that they are directly dependent on fetal activity. If the placenta is attached to the anterior wall of the uterus or in the case when the fatty layer on the woman’s abdomen reaches marked sizes, the baby’s tremors may be completely invisible to outsiders.

33 week of pregnancy - how many months is it?

Thirty-third obstetric week of pregnancy is exactly eight months and one week of your pregnancy. There is less than two months left before birth.

33 week of pregnancy for a woman is the time when she fully understands all the "charm" of pregnancy. Great effort worth getting up from the chair or self-laced shoes! The uterus has not fallen yet, and it is more difficult to breathe every day. There may be cramps and swelling of the limbs. But, what an expression of happiness and peace on the face of the future mom - after all, very soon she will meet with her treasure.

Weight of the child at 33 weeks of pregnancy, what is the norm?

Fetal weight at 33 weeks depends on many factors, including the sex of the child and the constitution of the parents. The norm is the weight of a child from 1900 to 2200 grams.

33 week of pregnancy - the deadline for the third planned ultrasound.

Biparietal size (BPR): 87mm,

frontal-occipital diameter (LZD): 105mm,

head circumference (OG): 316mm

femur length (dB): 64mm

length of tibia: 56mm

length of small tibia: 54mm,

shoulder length: 57mm,

radius: 47mm,

ulna length: 53mm,

foot length: 65mm

fetal length (height): 45cm.

Particular attention is paid to the study as the placenta - determine its degree of maturity. The more the placenta contains cysts or salt deposits, the worse it is able to perform its function. When establishing the diagnosis of "premature aging of the placenta", you will be prescribed drugs that increase uteroplacental blood flow and, most likely, re-ultrasound or CTG of the fetus in 1-2 weeks.

Child development at the 33rd week of pregnancy

At the 33rd week of pregnancy, the main points of fetal development are the organization of nervous activity and accumulation of fat. The formation and further improvement of connections between nerve fibers leads to the fact that the baby is better oriented in the surrounding space, his tactile sensitivity increases, and the movements of the limbs become more coordinated. The lungs can be considered mature, since the amount of surfactant in them would already allow the child to breathe independently if he was born on this period.

Sex at 33 weeks gestation?

Why not? But there are some reservations and contraindications.

Firstly, sex at 33 weeks is contraindicated if there is a threat of abortion. Consult your gynecologist. Secondly, sperm softens the walls of the cervix and can stimulate childbirth. In late periods, including the 33rd week of gestation, it is recommended to use a condom.

In addition, choose poses where there will be no pressure on the stomach, and avoid sudden jolts. Follow the color and consistency of your selections. If they are abundant, bloody - then you should consult a doctor.

Birth in the 33rd week of pregnancy

Births at week 33 are considered premature. At this time, doctors try to keep the pregnancy so that the child, while remaining in the womb, has more time for the development of all organs. But if you do not succeed in stopping labor activity, it remains to fight for the life and health of the child, to choose the safest tactics of childbirth.

In order not to provoke childbirth at the 33rd week of pregnancy, the expectant mother is required to follow a few simple rules:

  • abstain from alcohol and drug use
  • avoid injury
  • pay attention to contraindications when taking medicines,
  • avoid excessive exercise
  • refuse unprotected sex,
  • closely monitor your well-being,
  • consult a doctor for suspicious sensations (for bleeding - urgently to the doctor!).

Calculate the duration of pregnancy

(indicate the first day of the last menstruation)

As a rule, every pregnant woman has her own calendar, where she puts all the necessary data, outlines important dates, takes notes. With it, the term of pregnancy is usually calculated.

Given the nine-month duration of this period, calculations on a piece of paper seem to be a very routine exercise. But modern women live at a great time - they are not obliged to keep such a calendar at all and to engage in tedious arithmetic, if, of course, they are not so sentimental that they decided to keep their weekly notes as a memory of a beautiful time of gestation. You can safely entrust the program to calculate the duration of pregnancy. After all, for those who prefer to spend free hours on activities that are much more useful for the future baby and his mother, there are numerous virtual services like this one (we hint at our calculator).

What you need to calculate the duration of pregnancy?

In order to calculate the duration of pregnancy right now you only need to remember the date when the last periods began and enter it in the appropriate form fields. This number is the starting point of your pregnancy. We are talking about the so-called “obstetric weeks” - in the whole world it is customary to count the pregnancy in this way, although fertilization occurs only in the middle of the cycle. This measure is necessary for the convenience of doctors, but often causes surprise and misunderstanding in patients.

It is worth noting that with an ultrasound examination of the fetus you will encounter the fact that the known period of pregnancy can be calculated differently - by the weeks of the fetus’s life, that is, from the day of conception. You can even find a record on the sheet of results of the ultrasound study, which will contain both terms. In order not to be embarrassed by such contradictions, feel free to check with the doctors what kind of gestational age you are talking about, real or obstetric?

It is very important to emphasize that even if you precisely know the date of conception of the baby, in order to calculate the duration of pregnancy with a calculator, you need to use the date of the beginning of the last menstruation. If you find it difficult to remember, count off 2 weeks ago - with a standard 28-day cycle, ovulation often occurs on day 14.

I do not remember when they were menstruating. What to do?

Sometimes it happens that a woman does not know when she has had her last periods, for example, does not remember, does not follow the regularity of the cycle, or has just stopped taking contraceptives. If you have no idea what your gestational period is, you can calculate it with a fetal ultrasound. The data obtained in the early stages (up to 12 weeks), when the rate of development of the ovum is still very high and changes are noticeable literally every day, have the greatest reliability. Already only the size of the ovum without taking into account the proportions of the fetus will tell a lot about the doctor. In later periods, errors of up to 2 weeks are possible.

Another very informative method to calculate the duration of pregnancy is biochemical - a study of the blood of a woman for the content of hCG - human chorionic gonadotropin. This hormone is produced by the fetal egg and is present in the body only during pregnancy (by the way, the well-known instant pregnancy test is based on its determination in the urine). Содержание ХГЧ растет с каждым днем и при здоровой беременности четко соотносится со сроками. Стоит заметить, что это далеко не рутинный метод, требующий много временных и финансовых затрат и применяется он, в основном, по медицинским показаниям.

Нельзя не упомянуть о том, что выяснить срок беременности, рассчитать и предположить вероятный возраст плода в компетенции врача-акушера при проведении влагалищного исследования на ранних сроках. The main object of study in this case will be the uterus and palpation (manual) determination of its size. Of course, we are not talking about absolute accuracy, but the data obtained is quite enough to successfully monitor the health of the future mother and fetus.

Pregnancy tables weekly to date of delivery

  • Obstetrician-gynecologist (measurement of the size of the pelvis, weight and height., Blood pressure, size of the abdomen),
  • smear from the vagina, cervix, urethra on the flora and cytology,
  • swab from the nose to Staphylococcus aureus,
  • analysis of feces on helminth eggs,
  • general blood and urine analysis
  • hCG blood test - analysis of the level of hormones necessary to maintain pregnancy,
  • blood test to determine the blood group and Rh factor,
  • blood test for HIV, syphilis, hepatitis,
  • biochemical blood test to determine blood sugar levels,
  • blood coagulation test - Coagulogram
  • Visit to the therapist, oculist, lora, dentist.
  • seeding from the vagina - if you suspect the presence of sexually transmitted diseases,
  • A visit to an endocrinologist and other narrow specialists - by indications,
  • The first planned ultrasound is the assessment of fetal growth and development, the elimination of malformations and chromosomal abnormalities (risk assessment of Down syndrome and Edwards syndrome)
  • a blood test from a vein is a “double test” to determine the risk of chromosomal abnormalities and fetal developmental defects.
  • General analysis of blood and urine
  • Blood test for antibodies to rubella, toxoplasma, herpes, cytomegalovirus (CMV) (if still not delivered)
  • Urine analysis according to Nechyporenko to accurately identify possible diseases of the urinary system, if the general analysis of urine showed any violations
  • Coagulogram on detecting the level of Lupus anticoagulant - antibodies to phospholipids
  • Antibodies to the Rh factor in case of incompatibility
  • hCG blood test
  • General analysis of blood and urine,
  • “Triple Test” - Blood test for AFP (level of alpha-fetoprotein), hCG, for free estriol level - identification of the risk of fetal abnormalities (screening of Down syndrome)
  • General urine analysis.
  • A visit to an obstetrician-gynecologist (measurement of weight, blood pressure, size of the abdomen).
  • General urine analysis.
  • A visit to an obstetrician-gynecologist (measurement of weight, blood pressure, size of the abdomen).
  • General analysis of urine and blood.
  • second planned ultrasound examination - assessment of the growth and development of the fetus, the state of the placenta, amniotic fluid, detection of threatened abortion, exclusion of malformations and chromosomal pathologies
  • General analysis of urine and blood.
  • A visit to an obstetrician-gynecologist (measurement of weight, blood pressure, size of the abdomen).
  • General urine analysis.
  • Doppler ultrasound - a study of the blood flow of the placenta to eliminate the risk of developing placental insufficiency.
  • General analysis of urine and blood
  • A visit to an obstetrician-gynecologist (measurement of weight, blood pressure, size of the abdomen).
  • Blood test for glucose tolerance test and O'Sullivan test - elimination of gestational (diabetes) diabetes
  • General analysis of urine and blood
  • Blood test for antibodies with negative Rh factor
  • A visit to an obstetrician-gynecologist (measurement of weight, blood pressure, size of the abdomen).
  • Blood test for iron levels - exclusion of anemia
  • Urinalysis (before each administration),
  • Blood test for hemosyndrome - blood clotting,
  • A visit to an obstetrician-gynecologist (measurement of weight, blood pressure, size of the abdomen).
  • Ophthalmologist visit - with myopia,
  • A visit to the ENT - with the development of long-term rhinitis of the pregnant,
  • General urine analysis.
  • A visit to an obstetrician-gynecologist (measurement of weight, blood pressure, size of the abdomen).
  • The third planned ultrasound is the determination of the state of the fetus and placenta, the compliance of the size of the fetus to the gestational period, the heartbeat and respiratory movements of the fetus, the amniotic fluid.
  • CTG - cardiotocographic study - identifying the risk of hypoxia - oxygen deficiency in the fetus
  • General analysis of blood and urine
  • A visit to an obstetrician-gynecologist (measurement of weight, blood pressure, size of the abdomen).
  • General urine analysis
  • A visit to an obstetrician-gynecologist (measurement of weight, blood pressure, size of the abdomen). Blood test for syphilis, hepatitis
  • Vaginal smear on flora
  • General analysis of urine and blood
  • Full-term pregnancy
  • A visit to an obstetrician-gynecologist (measurement of weight, blood pressure, size of the abdomen).

Comments (5)

Nata | September 16, 2018 09:29

Hello to all! My husband and I have been trying to get pregnant for 10 years. There is nothing left. I’m having one pipe. Please tell me if there’s a chance to get pregnant with one pipe.

Mida | September 24, 2018 14:17

Check the second pipe for permeability, the procedure is called GHA. It is approximately 10 tons. After this procedure, the possibility of getting pregnant is great. Good luck to you!

Irina, Moscow Region | September 20, 2018 11:07

I with one pipe 4 gave birth

Inna | November 11, 2018 14:00

Hello! I have a very important question for you! The last months were 10.05.18, 14.06.18 did an ultrasound I was told 3-4 weeks! When could I get pregnant?

Inna | November 11, 2018 14:01

06/13/18 The test was positive!

About obstetric gestation

On average, women bear children 280 days, which are calculated from the first day of the last menstruation. This period is called obstetric. It is based on the definition of a woman's prenatal leave and a preliminary date of delivery. Obstetric term is also a kind of comparison scale, which is used to assess the fetus according to the results of the first ultrasound. How exactly do doctors in the antenatal clinic calculate the preliminary date of delivery for the last month? From the first day of the last menstrual period they “wind off” 3 months back and add 7 days. This date is the probable term of delivery. So, we will give an example of such a calculation. The last period of the future mother was on March 15th. It means that the preliminary delivery is scheduled for December 22. But, as practice shows, it is very rare that a child is born on this very day. After all, everyone is well aware that many factors, including genetics, affect the course of pregnancy. Therefore, childbirth can occur before the time specified by the doctor, and a little later. Usually the first birth occurs earlier.

As for the duration of pregnancy, it is also recognized with a focus on the last menstruation. If she was on March 15, then about 12-14 days the woman ovulated, her egg was fertilized. So, the gestation period begins from March 29. And if the patient contacts 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 on the 11th day after the onset of menstruation, in others - by 15, which depends on the duration of the cycle. In addition, on the first day of ovulation, conception may not occur. Some sperm cells can "work" for 3-7 days. A fertilized egg, moreover, takes time to move to the uterus and attach to its walls.

On the fetal period of pregnancy

So, you have defined obstetric term for the last month. But the doctor sometimes stuns you with the fact that this period does not coincide with the real, that is, embryonic. It is determined by the results of ultrasound. The difference can be a week or two. Such discrepancies sometimes make the future mother worry a lot, poison her life. After all, pregnant thinks that the baby is not all right. Women whose gestational period for an ultrasound examination is more or less than for menstruation is afraid of fetal abnormalities, as well as missed abortion. But we must understand that reading ultrasound is very difficult. Even experienced doctors can make mistakes in assessments, and even every child 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 the old ultrasound diagnostic devices show an uncertain picture of the development of the baby.

Practice shows that it is more accurately determined the duration of pregnancy up to 12 weeks, since during this period the embryo develops evenly and the stages of its development are obvious. Exactly determined length, coccyx parietal size of the fetus, the development of individual organs. But after this period, each baby develops individually. One may lag behind in its development for a variety of reasons, the other, like a forerunner, is ahead of the classical deadlines. Experts are guided by tables of development parameters. And if after the ultrasound the embryonic period of pregnancy does not coincide with obstetric - you should not panic. It happens, and it is quite normal. As well as the fact that a pregnant woman on this occasion asks many questions to an observant gynecologist.

How to determine the gestational age by the date of conception

It is known that conception occurs only during ovulation during the day after the release of the egg from the follicle. And the viability of sperm in the female genital tract is up to 3 days. It turns out that the date of sexual intercourse does not always coincide with the date of conception.

Ovulation occurs in the middle of the menstrual cycle. A woman who follows her menstrual cycle can quite accurately calculate the onset of ovulation. In addition, many at this time there are characteristic signs: aching pain in the lower abdomen, breast swelling, irritability, abundant vaginal discharge, increased sexual desire.

It should be noted that only those women who have a regular menstrual cycle can determine the duration of pregnancy by the date of conception.

Online calculator:

How to calculate pregnancy by ultrasound

To know the gestational age is possible by the results of ultrasound examination (ultrasound). It is determined according to the size of the fetus. The first ultrasound of the future mother is carried out at 12-14 weeks, but at this time it is no longer possible to determine the exact time, since the development of the fetus in each woman takes place individually. Finding the age of the fetus by ultrasound with an accuracy of one day is possible only in the first weeks after conception.

Find out the gestational age of the first movement of the fetus

The woman starts to feel fetal movements in the first pregnancy at 20 weeks, in the second - at 18 weeks. But this method does not always allow to set a period, because some future mothers can feel the first movements of the fetus earlier or later than the indicated weeks - some, due to the peculiarities of the structure of the organism, cannot feel the fetal movements, others confuse the bowels (increased gas generation) with stirring.

Determine the duration of gestational pregnancy

Human chorionic gonadotropin (hCG) - One of the most important indicators of the occurrence of pregnancy and its normal development. The hormone begins to be produced in the female body after implantation of the embryo in the uterus wall. The level of hCG in the blood allows you to find out the approximate age of the fetus. With multiple pregnancy, the level of the hormone in the blood increases in proportion to the number of fruits.