Pregnancy knowledge: Why is the expected date of delivery based on 40 weeks?
Pregnancy is an important stage in a woman\’s life because during this period, both the mother\’s body and the fetus require special attention and care. Among them, the calculation of the due date is one of the most important aspects of pregnancy. So, why is the expected date of delivery calculated at 40 weeks? This article will elaborate on the calculation of gestational age, female physiology, fetal growth and medical practice.
Part 1: Calculation of gestational age
The due date is calculated based on gestational age. Gestational age is calculated from the first day of a pregnant woman\’s last menstrual period, usually 40 weeks, which is 280 days. This is because the menstrual cycle is usually 28 days long, and ovulation is usually on the 14th day of the menstrual cycle. If you have sex during this period, the possibility of pregnancy is greatest. Therefore, the starting date for calculating gestational age is based on the menstrual cycle. Although every woman\’s menstrual cycle is different, the calculation of the expected date of delivery is based on average statistics. Therefore, the validity of the judgment of the expected date of delivery depends on the individual differences of women.
In addition, there is another method of calculating gestational age by checking the size and weight of the fetus through B-ultrasound to determine the expected date of delivery. This method usually provides a more accurate due date in the first trimester, but becomes less accurate as the fetus grows.
Part 2: Female Physiology
Why is the expected date of delivery calculated as 40 weeks? This also needs to be considered from the perspective of female physiology. During pregnancy, the fetus needs to complete its development in the mother\’s body. Under normal circumstances, the longer the pregnancy, the more beneficial it is for the healthy development of the fetus. A pregnancy that is too short may result in underdeveloped fetal organs and systems or even defects. In addition, a short pregnancy period may also lead to problems such as low fetal weight and a reduced incidence of full-term babies.
Excessive pregnancy period is also not conducive to the healthy development of the fetus, because as the pregnancy period prolongs, the weight growth rate of most fetuses begins to decrease and their growth slows down. If the pregnancy exceeds 42 weeks, the blood and oxygen supply to the child in the mother may be reduced, and the fetus may also have problems such as dystocia due to insufficient energy reserves. Therefore, the calculation of 40 weeks of expected delivery date is not random, but a conclusion based on the physiological characteristics of women.
Part 3: Fetal Growth
Another reason why the expected date of delivery is calculated at 40 weeks is because the growth of the fetus during pregnancy is a long process. In the first trimester, the fetus is only a few millimeters long and requires the mother\’s supply of nutrients and oxygen to complete the development of its organs and systems. In the second trimester, the fetus has grown into a small person. Its gender can be observed through B-ultrasound, and the development of different organs and systems has gradually matured.
In the third trimester of pregnancy, the fetus is mainly gaining weight and storing energy. It needs to continuously absorb nutrients from the mother\’s body while excreting waste and carbon dioxide through the placenta. When hormone levels change in a pregnant woman\’s body, the growth and development of the fetus can be affected. Therefore, 40 weeks of pregnancy is very suitable for mothers to give birth and ensure that the newborn\’s birth weight and physical condition are in optimal condition.
Part 4: Medical Practice
When pregnantWhen you begin to receive medical examinations and pregnancy care, the expected date of delivery will become an important indicator to communicate with your doctor. Doctors can use the expected date of delivery to understand the health of the mother and fetus, such as gestational diabetes, polyhydramnios, premature birth and other issues. Doctors can also determine whether a woman is ready to give birth by checking indicators such as uterine contractions and cervical dilation. Therefore, the calculation of the expected date of delivery has great reference value for doctors to decide the time of obstetrics and gynecology surgery and choose the method of inducing labor.
Conclusion
Through the above explanation of the calculation of the expected date of delivery based on 40 weeks, we understand that the calculation of the expected date of delivery is based on gestational age and is closely related to female physiology and fetal growth and development. In medical practice, the expected date of delivery is also an important indicator for maternal health care and for doctors to judge whether to give birth. Therefore, it is crucial for pregnant women and doctors to understand and master the calculation method of due date.
