The embryo is the early stage of human development, starting after fertilization. It lasts from week two to week eight of pregnancy. At fertilization, the sperm and egg combine to form a zygote. The zygote begins to divide and grow as it travels to the uterus. Once in the uterus, the zygote becomes a blastocyst, which then implants into the uterine wall. This implantation marks the official start of the embryo phase.
During the first few weeks, the embryo goes through rapid cell division. Layers of cells begin to form. These layers will develop into different parts of the body, like the skin, brain, and organs. By the end of week four, the heart starts to beat, and the neural tube begins to form. This tube will later develop into the brain and spinal cord.
Important Changes in the Embryo
Weeks five through eight of pregnancy mark crucial changes in the embryo. The brain and spinal cord continue developing. The eyes, ears, and limb buds also begin to form. These buds will grow into arms and legs. By the end of week eight, many of the internal organs, such as the liver and kidneys, have started to develop.
Around week eight, ir officially becomes a fetus. This is because the basic structures of the body are in place. During the embryo stage, the risk of miscarriage is highest. It’s highly sensitive to harmful factors, like certain drugs, alcohol, or infections. It’s important for pregnant women to avoid harmful substances during this time.
Overall, the embryo stage is the foundation of a healthy pregnancy. Many of the most important systems and organs begin forming in these weeks. Proper prenatal care during this time supports a healthy embryo and sets the stage for a smooth pregnancy.