Fetal Development: Month 3

This is the third month of fetal development. Baby starts looking less like a tadpole and more like the cute little bundle of joy you will hold at birth. Among the major milestones in this stage are the development of baby's reproductive system and hands and feet!

Week 9: Less Like a Tadpole

Baby’s body grows furiously and catches up with its extra long spinal cord, making the embryo look less like a tadpole and more like the little baby it is. Continuing the development of baby’s digestive system, baby’s pancreas, bile ducts, gallbladder and anus are now in place. Baby’s reproductive system begins to develop at this stage – testes for a boy, or ovaries for a girl. Baby’s muscles and movement continue to develop, and you may be able to hear baby’s heartbeat by using a Doppler device. Size check: baby is approximately 1 inch long!

Week 10: Fingers and Toes

Now at about 1 ½ inches, baby starts to develop fully separated fingers and toes. Baby’s bones and cartilage are also forming, and baby’s knees, ankles, and elbows become more defined at this third month of fetal development. In fact, baby’s elbows should already be in good working condition. Baby’s brain will produce almost 250,000 new neurons every minute. Baby’s face sees the change of eyelids from transparent to a more solid consistency, the ears take on their final form, and inside that little mouth, teeth buds begin to develop. Baby’s digestive system continues its progression as the stomach begins to make digestive juices and the kidneys produce more urine. Baby’s reproductive system is on schedule, and baby boys start producing the male hormone testosterone.

Week 11: Is it a Boy or a Girl?

At the end of this week, baby’s external genitalia will develop into a recognizable penis or clitoris and labia majora. Fingernail and toenail beds begin to form and nipples become more visible. Baby’s ears in almost final shape are moving up and to the side of the head to find their final location. Baby’s torso is lengthening and baby is now about 2 inches long and weighs about 1/3 of an ounce. To support this phenomenal increase in size and weight now and up to the time of birth, the blood vessels in baby’s placenta are growing larger and multiplying.

Week 12: Fingernails and Toenails

Now almost 3 inches long and half an ounce heavy, baby’s circulatory system is actively producing red blood cells in the liver and white blood cells in the bone marrow. Baby’s digestive system is beginning to practice contraction movements to aid in digestion. And baby’s endocrine system has the pituitary gland at the base of baby’s brain start producing hormones. By now, most major organs and tissues in baby’s body have developed. Baby’s eyelids will now close to protect baby’s developing eyes and will not reopen until the 28th week.



References:

Murkoff, Heidi and Sharon Mazel. What to Expect When You're Expecting. Workman Publishing Company, Inc. 2008

The Mayo Clinic. "Fetal Development." www.mayoclinic.com

The Westside Pregnancy Clinic. "Fetal Development." www.wpclinic.org




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