Pregnancy is usually 10 months, but not absolutely, some pregnant women may experience preterm labor, where the fetus develops less than 10 months, and some pregnant women may experience term labor, where the fetus develops more than 10 months before delivery.
After a successful pregnancy, a woman will project her pregnancy based on her last menstrual period, and the projected due date will be exactly 10 months or 40 weeks, and delivery within 2 weeks before or after the due date will be considered a full-term labor.
Not all pregnant women are able to deliver their babies on their due date. Some babies may be born prematurely, for example, if there is a combination of infections of the lower genital and urinary tracts, premature rupture of membranes, or laxity of the cervical opening during pregnancy, which can lead to delivery at less than 10 months of gestation.
Some fetuses may be born prematurely, with no sign of labor at the full 42 weeks of pregnancy or more. In principle, labor is usually induced by intervention or cesarean section when 41 weeks have been reached.