Fetal Development

Making an informed decision...


 

“Life is present from the moment of conception.”

-Dr. Jerome Lejeune, Late Professor and World Renowned Geneticist, University of Desecrate, Paris


Day 1

Fetal Development: First TrimesterThis pictures a fertilized egg only thirty hours after conception. Magnified here, it is no larger than the head of a pin. Still rapidly dividing, the developing embryo, called a zygote at this stage, floats down from the fallopian tube and towards the uterus. When fertilization occurs, the baby's features, including sex, hair and eye color have already been determined.


Week 4

A pregnancy test taken at this point can measure hCG, the pregnancy hormone in the mother's urine, and tell her if she's pregnant. By now, the embryo is completely attached to the lining of the uterus and draws nourishment from its mother.


Week 5

The heart, about the size of a poppy seed, is the first organ to function- it begins beating just 21 days after fertilization. The first signs of brain development are evident and the foundation of every organ system is already established and beginning to develop.


Fetal Development: Week 7

Week 7

The baby is now 1/3 of an inch long. The embryo makesits own blood. The arm buds look like tiny paddles and the leg buds look like flippers. Depending on the baby's gender, the testicles or ovaries are beginning to form.


Fetal Development: Week 8

Week 8

The baby is now about 1/2” long from head to bottom. The fingers begin to develop and the embryo has nostrils. Lungs begin to develop. Taste buds are forming on the tongue, tooth buds for 'baby teeth' are taking shape in the jaw and eyelids begin to form.


Weeks 9-12

The heart is almost completely developed and the heart rate can be heard on a Doppler machine at the doctor’s office. The face is well formed and the eyes are almost fully developed. The eyelids will close and not reopen until the 28th week. Arms, hands, fingers, legs, feet, and nose are fully formed. Because the baby has all of the major organ systems and is a distinctly recognizable human being, he or she is no longer called an embryo but is now known as a fetus, a Latin word for "young one." The baby is about 2 inches long and can yawn and suck. A baby boy begins to produce the male hormone, testosterone.


The Second Trimester


Fetal Development: Second Trimester

Week 13-18

The brain is fully developed and the baby can suck, swallow, and make irregular breathing sounds. Muscles tissue is lengthening and bones are becoming harder. Liver and organs produce appropriate fluids. Eyebrows and eyelashes appear and the baby can coordinate the movements of its arms and legs, though his or her mother will not likely feel it yet. As early as 18 weeks the baby can feel pain (New England Journal of Medicine).


Fetal Development: Week 20

Week 20

The baby is now about 10 inches long from head to heels and weighs 11 ounces. “Quickening” (When the mother can feel the baby moving) usually occurs around this time. The baby has unique waking and sleeping patterns and even has a favorite position to sleep in. The pregnancy is about half over and the mother is beginning "to show."


The Third Trimester


Fetal Development: Third Trimester

Week 24

The baby weighs about 1 1/2 pounds and practices breathing by inhaling amniotic fluid into its developing lungs. The ear has developed to the point where the baby recognizes mother's voice, breathing and heartbeat. About a week ago, rapid eye movements began, an activity associated with dreaming.Some babies born at this stage of development are able to survive.


Week 25-28

The baby is now about 15 inches long and weighs about 2 1/2 pounds. With the support of intensive care, a baby born at this stage is capable of breathing air. The brain is developed enough to coordinate rhythmic breathing and regulate body temperature.


Fetal Development: Week 29-32

Week 29-32

A protective waxy substance called Vernix covers the skin. By birth, most of the vernix will be gone but any that is left is quickly absorbed. The baby has a hand and startle reflex. Footprints and fingerprints are forming.


Fetal Development: Week 38-40

Week 38-40

The baby is now around 20 inches long and may weigh 7 to 8 pounds. He or she has a plump body and a firm grasp. Typically, the baby is head down in the mother's pelvis and awaiting birth. Be patient - only 4 % of babies are born on their due date.