Ariyanna Black: 3.5 Fetal Development Timeline

The fertilized egg beings to grow, and the amniotic sac to provide cushion for the growing embryo. The placenta, mouth, lower jaw, throat, and a primitive face with dark spots are developing. Bloods cells are taking shape and circulation will begin. The baby is about 1/4 of an inch by the end of the month.

Facial features are continuing to develop. The ears begin as a little fold of skin on either side of the head. Tiny buds form that will eventually be legs and arms along with fingers, toes, and eyes. The neural tube, digestive tract, and sensory organs began to develop. At 6 weeks the heartbeat can be detected. By the end of the month, the baby is about 1 inch long.

The baby's arms, hands, feet, fingers, toes, and the eternal are fully developed. The baby is able to open and close its fists and mouth. Fingernails, toenails, and the beginnings of teeth are beginning to form. Reproductive organs start to form, but the gender is still hard to determine through an ultrasound. Bile is produced because the circulatory and urinary systems are working. By the end of the month is the baby is fully formed and all the organs and extremities and organs are present and will continue to form. The baby is about 4 inches long.

Eyelids, eyebrows, eyelashes, nails, and hair are formed, and the teeth and bones become denser. The fingers and toes are well-defined and the baby can even suck their thumb, yawn, stretch, and make faces. The nervous system starts to function and the reproductive organs and genitalia are now fully developed. The gender is able to detect and the heartbeat is audible. At this the baby is about 6 inches long.

The mother may begin to feel the baby move because they're developing muscles and exercising them, these movements are called quickening. Hair is starting to grow on the baby's head and the shoulders, back, and temples are covered by lanugo. The baby's skin is covered with a whitish, vernix caseosa. By the end of the month the baby is about 10 inches long.

The baby's skin is a reddish color, wrinkled, and the veins are visible through the translucent skin. Fingers are toe prints are visible and the eyelids start to part and the eyes are open. The baby responds to sounds by moving or increasing the pulse. By the end of the month, the baby is about 12 inches long.

Reserves of body fat develop as the baby continues to mature. The baby's hearing is fully developed and they can change positions frequently and respond to stimuli. At the end of the month, the baby is about 14 inches long.

The baby is continuing to mature and more reserves are of body fat are being developed. They can see and hear and the brain is rapidly developing. The lungs still may be immature, but mos internal systems are ell developed. The baby is now 18 inches long.

The baby continue to grow and mature and the lungs are fully developed. Movement is tight but the baby's reflexes are coordinated so they can blink, close their eyes, turn their head, grasp firmly, and respond to the outside. Their position changes to prepare for labor and delivery. By the end of the m month the baby is about 18 to 20 inches long.