What is Pregnancy?

Pregnancy is the development and fertilization of one or more offspring called as a fetus or an embryo, in a woman’s uterus. In a pregnancy, there can be multiple gestations, as in the case of twins or triplets. Childbirth usually occurs about 38 weeks after conception; in women who have a menstrual cycle length of four weeks, this is approximately 40 weeks from the start of the last normal menstrual period (LNMP). Human pregnancy is the most studied of all mammalian pregnancies. Conception can be achieved through sexual intercourse or assisted reproductive technology.

Healthcare professionals name three different dates as the start of pregnancy:

  • The first day of the woman’s last normal menstrual period, and the resulting fetal age is called the gestational age
  • The date of conception (about two weeks before her next expected menstrual period), with the age called fertilization age
  • The date of implantation (about one week after conception).