Pregnancy and Fetal Development

Month 1
Hereditary characteristics are set when the sperm met the egg. The man's sperm determine the sex. The fertilized egg develops from a single cell to an embryo -- already with a head and body. The embryo grows inside a sac of amniotic fluid (bag of waters). The brain, eyes, mouth, inner ears, digestive system, arms and legs are starting to develop. Brain, nervous system, heart and lungs are forming. The heart begins beating around the 25th day. Tiny spots for ears, eyes and nose exist, and arm and leg buds are forming

Month 2
Eyes and ears are in a critical time of growth. Facial features are forming. Cartilage, skin and muscles are starting to shape the fetus' body. The umbilical cord has formed. Fingers, toes and fingernails are forming. Stomach, liver, and kidneys are developing. It is now just about 1 inch in length and weighs less than an ounce.

Month 3
Teeth, lips and genitals begin to develop. There are 20 buds for future teeth. The head is large, since the brain grows faster than the other organs. Fingers, toes, and fingernails are forming. Stomach, liver, and kidneys are developing. The heart is beating. By the end of this month, organs are formed and most are working. The fetus is still too tiny for the woman to detect movement. It weighs about 1 oz and be about 2 1/4 in. long.

Month 4
Hair, eyebrows, eyelashes, fingernails and toenails are forming. There are vocal cords and taste buds and can now suck its thumb! The fetus begins a growth spurt in length and weight. It is about 7 in. long and weighs about 5 oz. Ears, arms, hands, fingers, legs, feet and toes are completely formed. Reflex movements allow the elbows to bend, legs to kick and fingers to form a fist.

The heart is beating about 120 to 160 beats a minute. Blood goes through the umbilical cord to the fetus. About 1 cup of amniotic fluid surrounds the fetus in the sac. The kidneys circulate the fluid swallowed by the baby back into the amniotic sac. The fetus is still too tiny for the woman to feel movement.

Month 5
The fetus now has hair, sleeps, and wakes at regular intervals. Movement becomes more frequent -- the woman can now feel the arms and legs move. There will be active times and quiet times. Skin is protected by a white cheesy secretion (vernix caseosa). The fetus moves in the amniotic fluid. The skin is wrinkled and red and is filling out with fat. Eyelids are still closed. Fingernails are growing. A doctor will be able to detect a heartbeat. The fetus is about 8 to 12 in. long and weighs less than 1 lb.

Month 6
The fetus can frown , squint and hear sounds inside the womb. Unique fingerprints and footprints have formed. He can now cough and hiccup, and is big enough to be felt when the woman's abdomen is examined. The skin is still wrinkled and red. The fetus is about 11 to 14 in. long and weigh about 1 to 1 1/2 lbs.

Month 7
The movements are more frequent and vigorous. A fine, soft hair called lanugo covers the body. The brain and nervous system are growing quickly, and the heartbeat might be heard by another person placing an ear on the woman's abdomen. Testicles of boys start to move down into the scrotum. Sleeping and waking times are defined. He may suck a thumb and is now 15 in. long and weighs about 2 1/2 to 3 lbs.

Month 8
The fetus is growing and kicks are felt much more strongly. The bones continue to harden. He now looks much the same as he will at birth, but his body still needs some filling out. Now the fetus hears sounds outside the woman's body and his eyes are open. The fetus is active, with patterns of sleep and wakefulness. He may settle into the birthing position. The body is now mature enough to survive if he is born during these weeks. He is about 18 in. long and weighs about 5 1/2 lbs.

Month 9
By the end of this month, the baby will be fully developed. The bones of his head will be soft and flexible for delivery. In most cases, babies ready to be born will turn head-down toward the cervical opening, with their feet up under the woman's ribs. The eye color is dark gray. This may change after birth. The fingernails become complete and may grow long.

The baby may seem quieter because there is less space to move. There are periods of sleep and activity. The baby's organs are maturing so the baby will be ready to breathe and grow on her own after birth. About 1 quart of amniotic fluid surrounds the baby.

"Birth" isn't the beginning of the baby's life — it's just one chapter in a continuing story. In fact, he will continue to develop, just like in the womb, until he reaches the age of approximately 23 years!