Questions? Call 866-746-7383
Fast, free US ground shipping

$10 ground shipping to Canada

1st Trimester

$0.00
Description

Pregnancy - Your First Trimester Pregnancy is measured in trimesters from the first day of your last menstrual period (LMP), totaling 40 weeks. The first trimester of pregnancy is week 1 through week 12, or about 3 months. Early development Your actual pregnancy begins at the time the egg is fertilized by a sperm cell. During the following week, the fertilized egg grows into a microscopic ball of cells (blastocyst), which implants on the wall of your uterus. This implantation triggers a series of hormonal and physical changes in your body. The third through eighth weeks of growth are called the embryonic stage, during which the embryo develops most major body organs. During this process, the embryo is especially vulnerable to damaging substances, such as alcohol, radiation, and infectious diseases. Having reached a little more than 1 in. in length by the ninth week of growth, the embryo is called a fetus. By now, the uterus has grown from about the size of a fist to about the size of a grapefruit. 2nd Trimester
3rd Trimester
Get daily baby facts sign up for your own personal page