Every woman wants to know the period of her pregnancy, the approximate date of birth, as well as what happens to her and her child.Get this information from specific calendars, which are listed in detail all the changes in her body.And so many people are interested in how to calculate the calendar by week pregnancy.
how to calculate gestational age
definition of pregnancy is necessary in order to determine the expected date of birth.Also, it helps to find out whether there were any irregularities in the process of prenatal development of the child prenatal development of the child: week after week .
Pregnancy can often be different from the date of the incident of sexual intercourse.And even if fertilization occurred after a single sexual intercourse, the exact date of conception is still unknown.This is due to several factors:
- from the moment of ovulation Ovulation - How to determine as accurately as possible? .Depending on the length of the menstrual cycle, ovulation can occur between the eighth for his sixteenth day;
- with a viable egg (it normally lives only one day);
- with viable sperm.In the acidic vaginal environment they live about six hours, and the fallopian tubes - up to six days.
This means that fertilization can occur during the period from the eighth to the eighteenth day of the cycle.Therefore, there are several ways in which you can find pregnancy.These include the following:
- Date of the first day of last menstruation (obstetric gestational age);
- Date prospective conception (embryonic period);
- As gestation, which was installed when you first visit a gynecologist pregnant woman;
- by ultrasound (US);
- In fetal movements.
When a woman comes to the doctor and he confirmed the pregnancy, maternity specialist calculates time.He is forty weeks, or two hundred and eighty days.From obstetric fetal period is characterized by about two weeks, its duration - thirty-eight weeks.
ultrasound helps determine which week of pregnancy is a woman.With the help of this study, determine the size of the fetus and then special tables determine their compliance with any obstetric week period.
find out the duration of pregnancy can date the first baby move in the womb of a woman.In nulliparous this is the twentieth week, and multiparous women - at the eighteenth week of pregnancy.
definition delivery date
establish the exact date of birth can not be a woman, and therefore it is determined only suspected.There are several ways:
- by last month.The first day they should add two hundred and eighty days.To make it easier to find out the date of birth, you can use the formula Negele.To do this, from the first day of the last menstrual period to count the ensuing three months, and then add seven days;
- By the time the first baby move.If a woman primapara then added to this date twenty weeks, and if it multiparous - twenty-two;
- As a result of ultrasound;
- By the gestational age, which was established at the first visit to the doctor pregnant.Problem with this method is the minimum if the woman turned to the gynecologist in the first twelve weeks of pregnancy.
All information obtained using such methods should complement each other.This helps to establish the most accurate due date.
Why pregnancy calendar
With calendar pregnancy every woman can keep track of how her baby is developing.From a pregnant woman can get full information on what changes occur in her body and the fetus is formed in his organs and systems.
The calendar is easy to keep track of when you need to visit the doctor and tests.This system also helps to find out whether the pregnancy proceeds normally, or if there are any pathological disorders.
How to calculate the pregnancy calendar
Calculate pregnancy calendar can help many online calculators.In order to make the most of them, a woman needs to know the date of the first day of the last menstrual period, then there are calculators count maternity pregnancy.
Some of the calculators calculate pregnancy calendar on the supposed date of conception Conception, ovarian cycle, fertilization and genetics baby , which is not always possible to install.Properly called such systems calendars fetal development Fetal development - week after week , and they usually lag behind obstetric calendars for two weeks.
woman may calculate your own pregnancy calendar.This first day of the first week is considered the beginning of the last menstrual period.
In the first two weeks of this pregnancy calendar has not come yet, and the body is just getting ready for it.Third week - is the period immediately after fertilization.
You can also use the calendar pregnancy trimester.It is more concise and describes all the changes in a woman's body for three periods:
- first trimester (the first to the twelfth week).At this time, laid and begin to develop all the vital organs and systems of a child.This is the most dangerous period for the fetus because any adverse changes in the mother may lead to his death;
- second trimester (from the thirteenth to the twenty-sixth week).Fully formed the skeleton, muscular system and brain continue to develop;
- third trimester (twenty seventh fortieth week).The fetus is fully formed and at the end of this period, the process is ready to birth.
is important to understand that the development of the fetus takes place in every woman individually and depends on many factors.All figures are indicated in the calendar - it averages.
pregnancy calendar gives her information about all the processes taking place in her body and the body of the fetus.With his help she would be able to make it normal runs her pregnancy.