40 Weeks: Growth of the Embryo and Fetus During Pregnancy
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Watch and Learn
This amazing prenatal video chronicles how a human being develops and grows from a single-celled organism to newborn infant. Through a combination of animation, action, fetal photographs, and ultrasound images, watch a pregnancy unfold in a new and exciting journey of discovery. Detailed photos of the embryo and fetus through each trimester of pregnancy make for an interesting lesson in biology and human development.
What’s Happening Inside?
Fertilization, also called conception, occurs when a man’s sperm joins with a woman’s egg in the fallopian tube. The fertilized egg, also called a blastocyst or embryo, moves into the uterus where it will implant and start to grow. In the first month of life, the embryo grows to 10,000 times its size. By the third week, though still small, the tiny heart begins to beat. In the second month of life, the developing child is now called a fetus, which is Latin for “little one.” By eight weeks all body systems are present, and the fetus can suck her thumb. In the third month, the fetus can now squint, swallow, and move his tongue. He sleeps and awakens. Fingernails and toenails form, and he now has his own unique set of fingerprints.
In the fourth month, the brain has begun maturing. Her taste buds are working, and fine hair begins to grow on head, eyebrows and eyelashes. Facial expressions similar to the baby’s parents can be seen at this time. In the fifth month, sleep habits develop, and the child is very active. Mom can feel the baby kicking. In the sixth month, the child can now respond to sound, and her lungs are fairly well developed. She would stand a good chance of survival if born at this time.
By the seventh month, the fetus uses all four senses. He recognizes his own mother’s voice. In the eighth month, the child continues to gain weight. Her lungs are now fully developed and capable of making the transition to breathing air. At the month the baby arrives! The child will continue the human growth process, which began at the point of fertilization, for many years to come.
More about the Development of the Embryo and Fetus.
