Isn’t it amazing to think about the development of the baby that takes place in his or her first nine months of life!
At 3 weeks the heart, which is about the size of a poppyseed, is the first organ to function. The first signs of brain development are evident and the foundation of every organ system is already established and beginning to develop. The heart begins to beat within 21 days after fertilization or five weeks after the mothers last menstrual period began.
At 4 weeks the baby is growing rapidly. The basic structure for the entire central nervous system, the brain and the spinal cord, has been formed. The eyes are developing and the arms and leg buds are now visible. The heartbeat can be seen and heard on an ultrasound scan and is already beating about 100 120 times a minute.
At 8 weeks the elbows and fingers can be seen. The lungs have begun to develop. Taste buds are forming on the tongue and tooth buds for baby teeth are taking shape in the jaw. Eyelids are beginning to form. The hands and feet are perfectly formed.
By 9 weeks the developing ears and nose are visible and there is pigment in the retina of the eye. Nipples can now be seen on the chest. The limbs and fingers are growing rapidly and the bones in the arms are beginning to calcify and harden.
At 10 weeks the baby’s brain is rapidly growing; Each minute it will produce almost 250,000 new neurons. The upper and lower portions of the arms and legs as well as the fingers and toes can be clearly seen. The external ears are fully developed. The baby boy begins to produce the male hormone testosterone. For the first time the brain can make the muscles move on purpose.
At 11 weeks the baby’s eyelids are fully formed and remain closed to protect the developing eyes. The kidneys begin to produce urine. During the next several weeks his or her body will grow rapidly increasing in weight 30 times and tripling in length.
At 16 weeks the heart beats between 110 and 180 times per minute; it pumps 26 gallons of blood each day. The baby has eyelashes and fine hair growing on its head. The gender of the baby can be seen on ultrasound. If she is a girl millions of eggs are now forming in her ovaries. The baby can coordinate the movement of its arms and legs though his or her mother will not likely feel it yet. The baby can hear mom’s heartbeat and voice as well as outside sounds. Classical music calms the baby and hard rock agitates it. During the next two weeks the baby will almost double in weight.
At 18 weeks the skeleton is hardening and calcifying and is visible on ultrasound. The baby has reflexes such as blinking and frowning and has its own fingerprints and toe prints. The mother can start to feel the baby’s movements.
By 20 weeks, he or she has waking and sleeping patterns and even has a favorite position in which to sleep. The pregnancy is about half over and mom is beginning to show. Studies indicate that babies can feel pain by now and possibly even earlier.
At 22 weeks the male baby’s testicles are beginning to descend from the abdomen to the scrotum. Hair is visible on his or her head and body. From now until about 32 weeks the baby feels pain more intensely than in any other time in its development. The mom feels the baby punching, kicking and elbowing her.
At 24 weeks the ears have developed to the point that the baby recognizes his or her mother’s voice, breathing and heartbeat. Rapid eye movements began at about 23 weeks, an activity associated with dreaming. Some babies born at this stage of development are able to survive.
At 26 weeks the baby can react to sounds outside of the mother’s body. The eyes now respond to light and the permanent teeth buds are visible in the gums. Eyelashes and eyebrows are well formed and the hair on the babies head is growing longer.
At 34 weeks the baby is about 17 inches long and weighs approximately 4 1/2 pounds. It continues to grow and mature. The eyes are wide open and if a light is shown into them them the pupils will constrict. The head is now covered in hair, the fingernails reach the tips of the fingers, and the toenails are close behind. The mother can feel when her baby gets the hiccups. The lungs are still developing so a baby born at this stage will probably need some assistance breathing.
At 40 weeks the baby has reached about 20 inches in length and may weigh 7 to 8 pounds. He or she has a plump body and firm grasp. The babies head is typically in the down position in the mother’s pelvis and awaiting birth.
Holding Hands. This amazing picture was taken on August 19, 1999, at Vanderbilt University Medical Center in Nashville Tn., during an incredible procedure to correct spina bifida on an unborn child. Julie Armas was twenty one weeks pregnant with little Samuel at the time of the procedure. Read more about photojournalist Michael Clancy’s story at MichaelClancy.com.