Expecting mothers often have questions about the growth and development of their baby throughout pregnancy. While the mother's body changes rapidly and becomes visible, the changes in the fetus remain unseen. It is exciting to think about the wonderful changes the fetus will go through as it progresses during pregnancy. The period of 280 days is calculated from the beginning of the last menstrual period to the time of birth. From the moment of conception, the fetus is constantly changing and growing.
Pregnancy is divided into three separate time periods, or trimesters.
The first trimester begins at the time of conception and continues through the 12th week. The second trimester begins at the thirteenth week and continues through the twenty- eighth week. The third trimester begins at 28 weeks gestation and continues through birth. The first trimester is the time period in which the baby transforms from a fertilized ovum into a fully formed fetus. The changes in size and development are rapid and intensive.