How does the physician comprehend the pregnancy due dates so easily and precisely? Most people have wondered this at one time or another. The mainstream of doctors does this with the aid of a formula or know-how. But practically there are several ways to calculate the pregnancy due dates. The methods they use can be computerized applications, counting nine months from the day of your last period, to a number of traditional means. The one often common factor is they all are fairly accurate.You're pregnant and excited about maternity that you are going to experience for the first time ever. You must be wondering when is the baby due. Calculating the pregnancy due date is not complicated. There are several methods to calculate your estimated due date, but we all know that babies have their own timetables and most don't arrive on the estimated due date.
The age of the developing baby is called the "gestational age." Since the exact date of conception is seldom known, the date of the mother's last period is often used to begin calculating when the baby is due. The normal due date is 40 weeks after the first day of the last menstrual period.
Another way to calculate the pregnancy due dates is from conception, if known. Since ovulation and conception usually occur two weeks after the first day of the last menstrual period, the pregnancy due date is 38 weeks from conception.
In all probability the most precise way to substantiate the baby's gestational age and calculate the due date of birth is by confirming one of the above methods with an ultrasound. Ultrasound is used to measure the baby, and these dimensions are used to calculate gestational age. This test is non-invasive and can be performed as early as 5-6 weeks after the last menstrual period. The most perfect results are obtained between 8-18 weeks from the beginning of the last menstrual period. The outcome of the ultrasound, combined with the calculated date from the first day of the last period, provides a relatively firm due date.
Women whose periods are irregular come across difficulty using the first day of the last period or conception methods and usually must rely on the ultrasound examination. However, if the baby is unusually large or small, even the ultrasound may not provide enough information to estimate the due date.
Ovulation is the process in the menstrual cycle by which a mature ovarian follicle ruptures and discharges an ovum (also known as an oocyte, female gamete, or casually, an egg) that participates in reproduction. Ovulation also occurs in the estrous cycle of other animals, which differs in many fundamental ways from the menstrual cycle.
Prenatal testing is testing for diseases or conditions in a fetus or embryo before it is born. The aim is to detect birth defects such as neural tube defects, Down syndrome, chromosome abnormalities, genetic diseases and other conditions. It can also be used to determine the sex of the unborn baby.
Source : Wikipedia
