Women while expecting a child become more sentimental and attentive to the changes that occur to them. I want to extend the unforgettable waiting time for the baby, and there is no better way to do this than to monitor the pregnancy period using a special calendar, which allows you to count the time from the beginning of a new life in the womb by weeks and days.
Why is this needed?
The pregnancy calendar can be kept independently, after preliminary calculations, or you can use existing online calendars, which will calculate everything themselves and help you understand a lot of interesting information:
- find out when the conception was estimated;
- find out when the due date is expected;
- find out what the exact date is now: trimester, month, week and even the day of the current obstetric week;
- find out how many days are left before delivery;
- get information about what changes are taking place with the expectant mother and her baby.
The pregnancy calendar and calculator is based on the obstetric method of timing. The advantage of applications and programs is that a woman is relieved of the need to make independent calculations, the likelihood of a mathematical error that can creep into her calculation is eliminated, the result can be obtained in seconds by indicating only the start date of the last menstruation.
The weekly pregnancy calendar is a convenient help for the expectant mother and her relatives. It allows you to find out how the baby is developing, what physiological changes await the expectant mother this week, which of them will be completely normal, and in which cases it is better to consult a doctor to avoid problems.
The calendar will help you navigate in time when it is time to do certain tests, when you need to issue a maternity leave and a birth certificate, choose a maternity hospital, and start attending courses on preparation for childbirth.
How to calculate?
To determine the gestational age with a calculator or using an application, it is enough, as already mentioned, just to indicate the day, month and year of the beginning of the last menstruation. Do not confuse the terms: indicate exactly the first day of the last menstruation, and not the date of its completion!
Self-calculation will require a paper calendar, pencil and calculator.
Pregnancy is always calculated in obstetric weeks, and therefore it is important to begin with understanding what it is and why it is so established. A woman can conceive only during ovulation. Ovulation, in turn, occurs most often in the middle of the cycle, but deviations in one direction or another are possible. It is important to understand that until the ovum leaves the follicle, physiologically and biologically conception cannot happen.
But if a woman does not track ovulation by tests and ultrasound, then it can be very difficult to accurately determine the day of oocyte release. It is even more difficult to say which of the sexual acts led to conception, because after the release of the egg, it can be fertilized by spermatozoa, which are already present in the genital tract for 3, 4, and 5 days, and those that have just reached her, “fresh batch ".
Fertilization is possible on the day of ovulation and within 24–36 hours after it. Then the egg cell dies, and the fusion of the germ cells is impossible. If a woman has a regular sex life, then it is impossible to establish exactly which of the sexual acts led to pregnancy - there are no such methods.
To simplify the task for doctors and expectant mothers, a single obstetric method for calculating pregnancy was created for all women. The start date of the last menstrual period is taken as a basis. This is in the whole confusing story - the equation with the cycle, ovulation, conception, the most constant value that is beyond doubt. It was this day that they decided to consider the first day of pregnancy. There is no mistake: the first day of the cycle = the first day of pregnancy.
In this way, it turns out that by ovulation the period is already about 2 weeks, and by the date of delay in menstruation - 4 weeks. From gestational age (period from conception) obstetric differs by about 14 days, and this is very important to consider for those who consider pregnancy from the date of intercourse. It is because of this discrepancy that misunderstandings arise with the timing of the antenatal clinic - a woman believes that the doctor "overestimates" her term. In fact, there is no mistake.
Weeks should be counted from the first day of your last period. This will help you calculate the weekly deadline correctly. Difficulties may arise by months. The fact is that the obstetric month is exactly 28 days (exactly 4 weeks), and the woman sees other months in the calendar - there are 30–31 days in them.
It is more convenient to consider obstetric months, there are not 9, but 10 of them in pregnancy. But it is more convenient to divide the trimesters by calendar months - three calendar months in each. From 1 to 13 weeks - the first trimester, from 14 to 26 inclusive - the second, from 27 to childbirth - the third.
PDR is the estimated date of birth. It occurs at the end of the 40th week of pregnancy. More precisely, you can calculate it using one of the formulas:
- (date of the last monthly + 9 calendar months) - 7 days;
- (date of last menstruation - 3 months) + 7 days;
- date of last menstruation + 280.
It should be understood that the DA will be approximate. In practice, childbirth on this day occurs only in 5% of cases. The rest of the children prefer to be born on any other day of a rather long time interval - from 38 weeks to 42 weeks inclusive. And this is completely normal.
Childbirth does not take place according to the calendar and schedule, but when both the woman and the fetus are ready for this difficult process, the greatest of the sacraments.
Are the timing calculations accurate?
Obstetric timing is considered the most accurate. It is on this algorithm that all online calculators and all applications that can be downloaded and installed on a smartphone work. An error is allowed in the case of late or early ovulation in a woman. In this case, the real time from the received one will differ by about a week, no more, and this error does not have a large predictive value.
Since early ovulation is usually unfavorable for the onset of pregnancy, because the egg is immature, defective, then in most cases, if there is a shift, then in the direction of late ovulation. The only inconvenience this can cause is a slight lag of the baby in terms of fetometry by ultrasound. But an experienced doctor will quickly understand what the matter is and will reassure the expectant mother - the baby is growing normally. It's just that his gestational period is slightly less than obstetric suggests.
