PDR - what is it? Estimated date of delivery by conception date

At the moment when a woman learns of pregnancy, her attitude changes, as if by magic. Especially if the baby is the first and desired. The future mother has no experience, therefore, along with the joyful emotions as the term increases, so does the number of questions. Most of all I want to know when the child will be born.

If the visit to the doctor is not yet appointed, then you can find answers on specialized portals for parents. Many newcomers find it difficult to understand medical terminology, so most often you can hear the phrase: "PDR - what is this?" We will try to answer this popular question.

Waiting for a miracle

At the very beginning of pregnancy, future mothers are already presenting the day of discharge. In thought, the beloved husband meets at the maternity hospital with a bouquet of flowers, and grandparents are touched by a tiny sniffing little son or daughter. But can everyone get together in one day? What will the weather be like? And, in general, the day of the week? To answer all these questions, it is necessary to calculate the expected date of birth.

PDR is calculated in several ways, on which we will dwell in more detail.

Using ultrasound

Modern technology allows you to determine the sex of the baby even before his birth. Parents have time to come up with a name and buy things, a stroller and even make repairs in the nursery in the most suitable colors.

Through ultrasound, you can determine and PDR. What does this give us, and at what time is it best to do it? Experts say that the date of delivery is most reliably obtained before the onset of 12 weeks. The equipment is able to show the time with incredible accuracy - literally up to one day.

Of course, during pregnancy, ultrasound will be prescribed more than once. But in later terms, PDR is calculated taking into account the size of the fetus. As a rule, the development of children occurs individually, so you can not rely on these data.

For attentive

The next way to determine PDR is suitable for those who closely follow the menstrual cycle and know when ovulation occurs. The estimated date of delivery by the date of conception will most accurately tell you when the baby is born.

The only time when a woman's body is ready for conception is ovulation. At this point, a mature egg leaves the ovary. Some of the fair sex feel the onset of ovulation - increased attraction to the partner, pulling the pain in the lower abdomen or unusual sensations in the chest. This occurs in the middle of the cycle, which is from 28 to 35 days.

If a woman notes the menstrual period every month, the expected date of delivery according to the date of conception is fairly simple. By the middle of the cycle, 280 days must be added. Inexperienced moms think that the pregnancy lasts nine months. However, the formula "date of sexual intercourse + 9 months" has nothing to do with reality.

Formula Negele

The famous obstetrician Franz Negele studied the anatomy of the female pelvis, as well as the mechanism of birth. The question of PDR (what is it, and the most accurate way of calculating) interested the German doctor no less.

Many of Negele's studies today are considered fundamental. For example, most gynecologists in consultations still use the formula of a colleague from Germany to determine the date of birth.

One of the first things that doctors find out during the reception is the first day of the last menstrual cycle. From this date we take three months and add seven days. For example, if the monthly started on October 10, the PRD is set for July 17. With this calculation, it is assumed that the cycle is exactly 28 days.

The formula of Negele is incorrect to apply in the case of an irregular menstrual cycle, so in the arsenal of obstetricians there are other methods.

At the first reception

What is PDR, the gynecologist tells during the first visit. At 3-4 weeks, an experienced doctor can correctly determine the date of delivery during the examination. In the usual state, the woman's uterus has a pear-shaped shape, and with the onset of pregnancy it looks more like a ball.

As in the case of ultrasound, the longer the period, the more difficult it is to determine the moment of birth of the baby.

The first stir

Sometimes it happens that it is impossible to determine the date of birth with the help of the above methods. The proceeds come one more proven way, which works already on later terms.

Determine PDR can be after the first stirring baby - usually this exciting moment occurs at a period of 18-20 weeks, depending on whether the first time gives birth to a woman or not. If the experienced mother felt the baby, then expect delivery after 22 weeks. For the firstborn by the day of the first stirring, add 20 weeks.

Of course, some women claim that they feel the baby in the early stages, for example, at 14 or 16 weeks. Experienced gynecologists doubt such hypersensitivity and most often write off this for intestinal contractions.

Curiosity for the sake of

Why do future mothers want to calculate the PDR so much? What is this need, and is it important when the baby is born? Sometimes the day of childbirth is important for superstitious women or for those who want to see in the birth certificate just a "beautiful" date. Some pregnant women do not want to give birth on holidays or choose a maternity home based on the schedule of closing at the sink. In other words, there is enough reason to worry about this important day.

Popular interactive services can calculate the length of pregnancy by week. PDR calculators are also set to determine the date of birth, and most often as initial data it is necessary to indicate the number of days in the cycle and the first day of menstruation, after which the pregnancy was diagnosed.

What influences the PRD

In any case, it should be taken into account that the DA is just an estimated date, and no one will be able to guarantee birth on that day. Experts believe that pregnancy should on average last 40 weeks, but few women give birth on time. For example, during a multiple pregnancy, births almost always occur before the obstetric prognosis. In addition, other factors also have an influence: high blood pressure, polyhydramnios, diabetes and others.

A small percentage of expectant mothers, on the contrary, expects the baby until the 41st or 42nd week. This is also within the norm. Pregnant women are under the supervision of doctors, who at any time are ready to speed up the process a little.