How Your Fetus Grows During Pregnancy
Pregnancy begins when an egg and a sperm unite into a single cell in a process called fertilization that then leads to a series of changes in the body as the baby grows inside. From the time it is implanted until the end of the eighth week of pregnancy, it is called an embryo. From the ninth week until the pregnancy ends with birth, it is called the fetus. Pregnancy usually lasts about 40 weeks which is the time from the first day of the woman’s last menstrual period until she gives birth. The fetus undergoes many changes during this 40-week timespan to prepare it for life and so we will go through how your body changes as the fetus develops.
How time is broken down during pregnancyThe 40 weeks are often grouped into 3 trimesters, each lasting about 12-13 weeks each:
- The first trimester lasts from 0 weeks to 13 weeks.
- The second trimester lasts 14 to 27 weeks.
- The third trimester lasts from 28 weeks to 40 weeks.