Full term pregnancy lasts for about 280 days or 40 weeks - a concept popularized nearly 200 years ago by Franz Naegele.
In a method called Naegele's Rule, he calculated the date of birth by adding 280 days (due date) to the date of last menstrual period.
However, it has been found that only about 5 percent of women give birth on their 40th week.
Babies born between 39 and 41 weeks of pregnancy fare better than infants born during weeks 37 or 38, a study shows. A term birth is considered 37 to 41 weeks, but the new study suggests it is more of a continuum.
Previously it was thought that infant mortality risk was similar for babies born between 37 and 41 weeks. But the new study shows that this risk is increased when babies are born between 37 and 39 weeks of gestation, and that this risk decreases with each additional week of pregnancy.
In the past, a pregnancy that lasted anywhere between 37 to 42 weeks was called a term pregnancy. Below are the new definitions:
Early term: Your baby is born between 37 weeks, 0 days and 38 weeks, 6 days.
Full term: Your baby is born between 39 weeks, 0 days and 40 weeks, 6 days.
Late term: Your baby is born between 41 weeks, 0 days and 41 weeks, 6 days.
Postterm: Your baby is born after 42 weeks, 0 days.
Learn more about these findings at WebMD.
Having a healthy baby is an important thing to focus on in your pregnancy. Here are some great tips to help you have the best pregnancy, shared by VeryWell.