The issue of determining the date of birth is one of the most urgent for future dads and moms. Many Internet resources devoted to pregnancy and child-rearing, offer their users to determine the date of expected childbirth using special calendars or calculators. Future parents need only enter the number and month of the first day of the last critical days. Similar calculators allow you to determine both the most probable date of birth and the period in which a baby can be born - the accuracy of this method can be questioned a lot.
But you should not blindly trust the Internet. In order to accurately determine the date of birth, there are quite real and long-used methods in medical practice.
Methods of correctly determining the date of birth
Let's start with how doctors determine the date of birth.
At the first consultation about pregnancy, the gynecologist, as a rule, finds out the date of the last menstruation and, using the formula of Negele, calculates the day of childbirth.
According to this formula, from the 1st day of the cycle, 3 months are deducted and seven days are added. As practice shows, this method does not provide an opportunity to determine the exact date of birth, since it is designed for women with a 28-day cycle. In other cases this method gives an error in the greater or lesser side. And with an irregular cycle, this formula is not used.
Also, a method such as determining the expected date of delivery for ovulation can be used. This is not difficult at all. If we assume that the cycle lasts for 28-35 days, and the process of ovulation occurs in its middle, it is easy to determine the date of birth by conception, which supposedly occurred on the day of ovulation. If a woman is having difficulty with the day of ovulation, you can simply determine the middle of the cycle and add 280 days to this date.
The most accurate method for today is to determine the date of delivery by ultrasound. If you make an ultrasound before 12 weeks of pregnancy, you can find out the length of pregnancy to the nearest day and, accordingly, determine the day of childbirth.
The results of ultrasound study determine the duration of pregnancy and later in pregnancy, but in this case, the conclusion of ultrasound can not be taken as a basis for calculating the expected date of birth, as all children develop differently - someone faster, someone slower.
Another method that allows you to determine the date of birth is to establish the first movements of the fetus .
His first movements in the mother's womb are made by the child as early as twelve weeks. But the fact is that because of the still rather small size of the fruit, a woman can not feel them. It is possible to feel the movement of a woman who is expecting a baby for the first time, approximately at 20 weeks of pregnancy, and getting ready to become a mother again at 18 weeks. To calculate the date of birth according to the first perturbation, you need to add to this date, respectively, 20 or 22 weeks.
A fairly informative method is to determine the location of the uterine fundus.
Already from 14-16 weeks of pregnancy the doctor can determine the gestational age and the date of birth of the baby with an ordinary examination, determining the height of the bottom of the uterus to the touch. So, at a period of 16 weeks, it is located approximately between the navel and the pubis, in 24 - in the navel, and at 28 - above the navel by 4-6 cm.
Also, a doctor can measure the woman's abdominal circumference and calculate the date of birth according to this parameter. But this method does not differ high accuracy due to the individual features of the physique of each woman.
But whichever method is used to determine the date of the expected delivery, just at that time, only a small part of the women fit. Each pregnancy has its own way, and on the date of onset of labor, many factors, including multiple pregnancies, and the presence of concomitant diseases in women, can influence.