Terms of pregnancy: obstetric and embryonic; how to identify and not get confused in terms
Once for each future mother, the same special day comes. She learns about her new condition. And soon the woman will often hear the question: What is your (you) time? ; How to calculate the duration of pregnancy in order to correctly answer?
It’s pretty simple!
Almost always the answer to the question about the term of pregnancy will be based on the two most famous and popular methods of counting; obstetric and embryonic (from conception) terms
The onset of pregnancy is the first day of the last menstruation. This method is called obstetric. He does not take into account the individual characteristics of the woman’s body, but is almost universal. Any doctor will use it.
The obstetric method has its own logic. Calculation of the period is from the earliest stage of pregnancy – the beginning of the maturation of the egg.
According to the obstetric method, the doctor will determine the expected date of childbirth (PDR), as well as the period of maternity leave. In medicine, it is considered that the pregnancy lasts 280 days. It’s all known for 40 weeks or 10 lunar months.
Why 10 months, not 9? And why are the months moon? ; Blame; in this astronomy. The moon repeats its phases with a periodicity of 28 days (4 weeks). This is the lunar month. And if you count in calendar months, then only 9 can fit them into a normal pregnancy.
The onset of pregnancy is the first day of last menstruation plus 2 weeks. It is believed that it is in the middle of the cycle that ovulation occurs. At the same time, the period from one monthly to another takes an average of 28 days.
This method of calculating the term is called embryonic or true. But it is worth thinking about: is not the truth hiding somewhere else? From a medical point of view, ovulation can occur within 12-18 days from the start of the cycle.
Example. Oksana’s husband always went on business trips from the beginning of spring until late autumn. At home there were sometimes only one or two days a month. Soon after the next visit of her husband, Oksana realized that she was pregnant. And with a smile she thought she knew the exact date of conception – June 2. After all, before and after this day, she and her husband had not seen each other for almost two weeks. Last months at Oksana were on May, 18-21. And if we consider May 22 the beginning of the cycle, then the conception took place on the twelfth day. And the egg was already ripe. Or not?
Another important question here is how long does ovulation continue? If strictly in science, then a few seconds. After all, ovulation is only the exit of a mature egg from the follicle. But most of us consider ovulation and the next few (or even many) hours that an ovum will live in a female body. How many? Sometimes up to two days. By the way, about the same amount will live in the female body and sperm after sexual intercourse. And sometimes longer – up to a week.