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An interactive pregnancy calculator is a convenient service for calculating the date of birth and determining all significant stages of gestation. If the expectant mother knows the date of conception for sure, then you can enter it into the form of an interactive calendar and get the desired result. When this date is unknown, then the 1st day of the last menstruation can be taken as a basis. The service works very quickly, so in just a few seconds a woman will be able to get the information she needs. Now the expectant mother will know for sure when the baby will begin to respond to touch, when it will move for the first time and other important points.
If a woman suspects that pregnancy has occurred earlier or later than the onset of menstruation, then after undergoing a planned ultrasound, the necessary calculation can be made again. At the same time, the date of conception will now be as reliable as possible, since the doctor will determine it based on medical indicators. The pregnancy calculator is an interactive assistant that allows you to find answers to many questions.
Among the benefits of using a pregnancy calculator are the following factors:
After a woman finds out about her situation, she has many questions. She is interested in how long the stomach begins to increase in size, when it is necessary to undergo an ultrasound scan, when the baby is born, when it will be possible to feel the first movements of the crumbs, etc. Answers to these and many other questions can be found using the pregnancy calculator.
The calculator allows you to determine the exact terms of the trimesters of pregnancy, find out such important dates as the day of the expected birth, conception, and maternity leave.
A woman will know what signs of a developing pregnancy she needs to pay attention to, and what to ask the doctor during a scheduled visit.
The calendar will inform the woman about when and what tests she will need to take, when to undergo an ultrasound scan. The online pregnancy calculator is a kind of reminder that is always at hand.
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Pregnancy period – what is it?
After ovulation, when the egg is released from the ovary, it lives for 24 hours. This time is considered the most favorable for the conception of a child. When the cycle equates to 28 days, ovulation occurs on the 14th day from the start of menstruation. The spermatozoon meets the egg, fertilizes it, and a week later the embryo attaches to the inner lining of the uterine wall.
It is sometimes impossible to calculate the exact date of ovulation and conception. Therefore, doctors take the 1st day of the last menstruation as the beginning of pregnancy, and exactly 280 days later, delivery should occur. As a result, a paradox arises: the period began to be counted when the pregnancy itself had not yet taken place. Therefore, it should be understood that the embryo exists approximately 14 days before the date set.
Methods for determining the gestational age
The following methods are available to determine the gestational age and due date:
Passage of ultrasound.
Using the Negele formula.
Determination of the level of hCG.
Measurement of the uterus during examination in the office of a gynecologist.
Evaluation of one’s own sensations (according to fetal movements).
Obstetricians to determine the gestational age are guided by the data of an ultrasound examination. You can clarify them with the help of a gynecological examination of the uterus, as well as knowing the date of the last menstruation.
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Ultrasound is the basic method for determining the gestational age. You can count on maximum reliability only when the procedure is carried out after 10-12 weeks from the moment of fertilization. In the future, an ultrasound examination will not allow you to accurately determine the gestational age and the date of the expected birth. Therefore, it is so important to undergo an ultrasound scan in the 1st trimester of pregnancy.
The devices used by diagnosticians allow fixing a three-week-old fetal egg. The date of conception and the date of the expected birth of the doctor is calculated based on an assessment of the coccyx-parietal size of the embryo. This indicator can be determined after it reaches 3 cm or more. According to the results of the ultrasound, the doctor issues a conclusion. It indicates the embryonic and obstetric gestational age. The first characterizes it from the moment of conception, and the second – from the day the last menstruation began.
When the fetus reaches 22 weeks, it will not be possible to accurately determine its age. However, at this time, doctors evaluate the main criteria for the intrauterine development of the child. The size of the head, the circumference of the abdomen, the length of his femur are measured. If the indicators of the fetus do not correspond to its age, then intrauterine growth retardation can be suspected.
It should be understood that there are individual characteristics that the baby inherits, for example, short stature or a large head circumference. They appear in the third trimester, so it will no longer be possible to calculate the gestational age by ultrasound.
Determination of gestational age by the date of the last menstruation
If a woman’s cycle is equal to 28 days, then it is not difficult for her to independently calculate the date of birth. To do this, you need to use the Negele formula:
“PDMP (first day of last menstruation) – 3 months + 7 days = EDD (estimated date of birth)”
Calculation example: PDMP was on August 16, so August 16 – 3 months + 7 days = May 23. On this day, the birth will take place. In this way, all online pregnancy calculators calculate the date of birth.
To calculate the gestational age, you need to add the number of weeks that have passed since this date to the first day of the last menstruation.
Cases when it is not possible to determine the gestational age by menstruation:
The menstrual cycle is irregular or too long. If it exceeds 35 days, then ovulation will not occur on day 14, so it is impossible to calculate the exact date of birth using the Negele formula.
If there is a risk of miscarriage in early pregnancy. The main sign of a threat is often the appearance of scanty spotting. A woman can confuse them with menstrual bleeding, and will not even guess that she is in position. In this case, ultrasound can help in determining the duration of pregnancy.
If the woman is taking contraceptives. When the regularity of the scheme is broken, there is a chance to become pregnant. Ovulation in this case happens suddenly, so it is impossible to calculate the exact date of its onset.
Examination of a woman on a gynecological chair
Each woman must be examined by a gynecologist before registration.
It defines options such as:
The height of the bottom of the uterus;
The size of the uterus.
These indicators allow us to assume the gestational age, if not exact, then indicative. The error in the definition is due to the individual characteristics of the location of the uterus. In addition, a full bladder and the presence of fibroids can make examination difficult. In the event that a woman is carrying 2 or 3 babies, the uterus will be enlarged more than usual, which will also affect the accuracy of timing.
Determining the duration of pregnancy by the level of hCG
8-10 days after the conception has occurred, the level of chorionic gonadotropin (pregnancy hormone) begins to rise in the woman’s body. This number will double every day.
It should be understood that it is impossible to determine the gestational age by the level of hCG with 100% accuracy. The fact is that the boundaries of its norm for each week of pregnancy vary quite widely. Moreover, the hCG indicator can go off scale when carrying twins or triplets, as well as with various pathologies of pregnancy.
Movements and gestational age
As practice shows, a woman begins to feel the first movements from the 20th week of pregnancy. This pattern is valid for those expectant mothers who give birth for the first time.
If the birth is the second or more, then the woman can feel the baby’s movements already at 16-18 weeks of pregnancy.
It is impossible to determine the gestational age for this indicator by 100%. Sensitivity will be influenced by such factors as the thickness of the layer of fat between the uterus and the peritoneum, the individual characteristics of the fetus, etc. In addition, when a woman really wants to feel life inside herself, she can even take the passage of gases through the intestines for the movements of the fetus.
How to calculate the gestational age after IVF?
Many expectant mothers have questions about the reliability of calculations of the gestational age after artificial insemination, because an already developing embryo is placed in the uterine cavity.
Gynecologists calculate the gestational age, starting from 1 day of the last menstruation, and it does not matter how the conception was carried out. However, there is an exception to this rule: with IVF with a protocol for suppressing menstruation, 14 days are added by the day of embryo transfer, and only from this date the countdown of the gestational age begins.
Why do you need to know the exact gestational age?
The gestational age is an important indicator that acts as a guide for doctors in the following points:
Determination of the date of birth of the child;
Assessment of the development of the fetal body;
Planning for prenatal screening for chromosomal abnormalities;
Assessment of the child’s ability to survive outside the womb in the event of his early birth.
Knowing the gestational age will allow a woman to psychologically prepare for the date of the upcoming birth, and will also provide information about what happens to the baby in one or another period of its intrauterine life.