How to calculate the gestational age?

It is extremely difficult to calculate the gestational age by weeks and days with maximum accuracy. Some experts use ultrasound to track the period of ovulation. However, this method is used only if a woman is suspected of infertility. Accordingly, it can be assumed that the solution of the task up to the day is almost impossible. Both for the doctor and for future parents.

But there are a number of methods by which you can independently calculate the date of conception.

Calendar calculation option

When sexual intercourse in a woman occurs irregularly, it turns out to be much easier to determine the time period when fertilization has occurred. In such a situation, the expectant mother can almost accurately determine when the fastest sperm has reached its goal.

An alternative is the ability to use basal temperature graphs if a woman records such indications with a certain frequency. The received date must be reported to the doctor after the pregnancy is confirmed. As a rule, the doctor adds about two weeks to the date of the last menstruation.

This is due to the fact that for the observing doctor, another indicator for calculations is important - the term of obstetric pregnancy. Its indicators depend on the dates of the first and last day of menstruation. In this regard, it may seem that doctors are beginning to count the gestational age upon the first day of the menstrual cycle, which is not true. However, this method of calculation is as accurate as possible. This method of calculating the gestational age by weeks can also be used to calculate the estimated date of birth. To do this, add 280 days to the date of the onset of menstruation.

Another way is to use the Negele formula. It is necessary to subtract 3 months from the date of the last menstruation, and then add 7 days.

When the ovulation period is precisely determined, 264 days can be added to the first day of the last menstruation. As a result, the approximate date of onset of labor will be determined. However, such a calculation will have to be done independently, since doctors do not use such a technique. A woman can calculate the gestational age by the date of her period on her own, using the above information.

Ultrasound scan

Modern equipment makes it possible to calculate the gestational age by ultrasound. Ultrasound research is no longer a know-how, as it has been used for many years. With its help, you can not only check the status of the fetus, but also clarify the data on gestation. The most accurate are the results of studies when the gestational age is less than eight weeks. This is due to the fact that in the absence of any deviations, the development process of each embryo occurs in the same way. By the size of the fetus, you can most accurately calculate the gestational age by weeks.

It is important to take into account the fact that the number of errors with increasing time also becomes larger. This is due to the manifestation of individual signs of development. One embryo may have a larger head, while the other may have slightly smaller parameters, which is not a serious deviation.

As a rule, indicators with lagging or ahead of the boundaries of the week are considered insignificant. This is the norm, so no treatment is prescribed. The terms of pregnancy in any case are approximate and are established on the basis of measurements of the coccygeal-parietal region.

In the case where there is no probability of making an error with the determination of the gestation week, but the fetal size is more than 14 days behind, the observing specialist can make a diagnosis - intrauterine growth retardation. Unfortunately, such a case is not treatable. As for the activities that are carried out in the hospital, it is rather prevention. Therefore, it is important to move as much as possible, to eat only healthy food, not to be nervous and not to carry heaviness.

Inspection by a specialist

Most women, as soon as they discover a delay, rush to make an appointment with a gynecologist to check their suspicions. However, through a routine examination, it is impossible to determine the fact of pregnancy for sure. An increase in the uterus may be before the onset of menstruation. Active growth of the uterus is observed only at the end of the first trimester. The 5th and 6th week of pregnancy (usually the 2nd or 3rd week of delay) is characterized by sizes that exceed the normal parameters of the uterus. Visually, it can be compared with the size of a chicken egg. At the eighth week, the parameters increase to a goose egg, and at the 10th it can be compared with a female fist. You can more accurately calculate the gestational age in the first trimester.

First stir

Many gynecologists argue that the expectant mother should listen to her feelings and be sure to remember the date when she felt the baby’s first stir. After all, in this way you can calculate the gestational age. According to statistics, the first movements of the fetus appear on the 20th week. With repeated pregnancy - on the 18th. The date of stirring must be entered on the woman’s medical record, as it is also taken into account when determining the duration of labor.

According to the reviews of many mothers, the established gestational age may not always coincide with the expected ones, since in the third trimester the fetus may show individual signs of development within the normal range. Also, do not worry about overly responsible mothers who are afraid to skip the first movements, so as not to mislead the doctor when calculating the gestational age. Doctors are reinsured and analyze the indicators of ultrasound and Dopplerometry. In addition, the first movements are rather weak, but you can still feel them. If a woman lies on her back, then it is impossible not to notice the movement.

Along the length of the uterus

With the onset of the second trimester, many doctors begin to evaluate the parameters of the fetus by measuring the length of the uterus. To do this, use an ordinary centimeter tape. With each week, this figure should increase on average by a centimeter. There is an alternative option for determining the parameters through ready-made tablets that doctors often use:

The parameters and volume of the abdomen also matter, but in order not to be mistaken, this factor can be taken into account only in conjunction with others, it will not be able to show the gestational age to the nearest week. Volume should be measured at navel level.

If a woman is not obese, then the average parameter of the abdominal volume at the 32nd week reaches 85 cm. Shortly before the start of labor, the volume increases to 100 cm. This is due to the fact that the child begins to gain weight as quickly as possible.

With constant measurement of the length of the uterus, you can make sure that the development of the fetus is normal. If pathological processes occur, this criterion will help prevent the development of complications.

Heart tones

The first heartbeat is tracked at week 4 or 5. This is the second or third week of delayed menstruation. When you visit the planned ultrasound, you can hear the heartbeat, as well as make sure that the fetus is alive and develops normally. At later dates, the doctor can determine the heartbeat through the external uterine wall through the use of a special device. However, tones can be traced a little later, at 10-12 weeks. A little later, you can already track the movements.

To check the heartbeat, the supervisor uses a stethoscope at a later date. This is a special device that is applied at one end to the stomach of a pregnant woman, and the other to the doctor’s ear. Visually, it resembles an ordinary tube. Sometimes it’s quite difficult to hear the heartbeat for some reason. So, for example, the placenta, due to its location near the outer wall, can drown out the sound, or the cause may be a dense fat layer. However, this is not considered a threat or pathology. Among the serious reasons that need to be monitored are hypoxia or polyhydramnios. With increasing gestational age, the heartbeat should be heard more clearly.

HCG

A method used primarily in the early stages. However, an error still exists. To determine the level of chorionic gonadotropin, it is necessary to take blood for analysis from a vein. As for the approximate results (in honey / ml), they are as follows:

• second week - 25/300;
• the third - 1500/5000;
• the fourth - 10,000 / 30,000;
• the fifth - 20 000/100 000.

From these values ​​it is clear that the results obtained have a wide range, which means that there is a probability of errors. Therefore, it is more advisable to use this method not to calculate the gestational age by days, but to establish the fact of pregnancy itself.

It is important to note that the level of hCG with normal development of gestation should increase daily. This is due to the fact that the production of this hormone occurs exclusively with the development of pregnancy.

Calculation of ovulation indicators

When the egg leaves the follicle, ovulation occurs. During this period, sperm fertilization may occur. For women planning a pregnancy, this period is of great importance, since with its definition it is possible to plan the birth of a child. There are several ways to determine ovulation:

1. Using special tests that you can buy at the pharmacy. Many of them are highly reliable.
2. If the cycle is regular, there are no malfunctions, then the ovulation period can be set by measuring the basal temperature.
3. Also, the onset of ovulation is also indicated by small changes in the discharge. They become more viscous, their number also increases.

Normally, this period passes closer to the middle of the entire cycle. If its duration is stable and does not change, then the number of days of the cycle can be divided into two and add the obtained value to the beginning of the last menstruation. This is an effective way to calculate the gestational age at conception.

Using an online calculator

Modern technical capabilities help to avoid manual calculations. In this case, online calculators or special applications for electronic gadgets will help. Their use does not imply any difficulties. First you need to specify the date of the probable start of menstruation in the format day, month and year. Next, click on the button to start the calculation. In automatic mode, the following information should appear:

1. Estimated date of onset of labor.
2. The approximate number of days remaining before delivery.
3. What week of pregnancy is the woman and what is the trimester in a row.
4. Estimated date when conception occurred.

This method is similar to the method of calculating the period of pregnancy by menstruation.

Basal temperature

Thus, it is possible to calculate the gestational age at the initial stage. The temperature is measured in the anus. As a rule, before the onset of the ovulation period, its indicator should be in the range of 37 ° C. After the egg is released, the temperature drops sharply, and then rises to 37.2 ° C. This is due to the fact that the level of hormones changes sharply.

According to the recommendations of doctors, it is necessary to monitor these parameters for four months. This will make it possible in time to establish the threat of miscarriage and preserve the health of the woman. This will be indicated by an unplanned sharp drop in temperature. In the case when an excess of 37.7 ° C is observed, we are talking about the development of the inflammatory process.

It is also important to take into account that measuring temperature is best in the morning - immediately after waking up. If hormonal drugs are prescribed, then during this period it should not be measured, the information will be unreliable. It should be noted that a constant measurement of temperature in the anus helps to determine the gestation period as accurately as possible.

Observation by a doctor throughout all three trimesters is mandatory for all women awaiting the appearance of a baby. Timely determination and calculation of the gestational age will help determine the day of conception as well as the estimated date of birth as accurately as possible.