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NOTE: Click on the calendar page to view a picture of a preborn child at that stage of development or visit our Baby Steps DVD website to watch a video of amazing 4D ultrasound images.

For a brochure containing this information and pictures, see our Resources page for My Secret Life.

Fertilization: A new human being begins the first day of his life as a single-cell human embryo at the beginning of the process of fertilization, on first contact between his father's sperm and his mother's oocyte.

At that moment, a new human person, who carries with him as much information as 50 sets of the Encyclopaedia Britannica, is formed. This genetic information-DNA-will determine all of this little person's physical characteristics and much of his intelligence and personality.

Day
2
Our little friend is now three cells big. His cells will continue to divide as he starts down his mother's Fallopian tube towards her uterus (womb), where he will get the food and shelter he needs to grow and develop.
Days
6-7
Implantation into his mother's uterus begins and all the while he continues to grow. As his cells multiply, they differentiate to perform specific functions - circulatory, muscular, neural and skeletal.
Day
14
Implantation is completed around this time and his mother misses her first menstrual period.
Day
20
His heart, brain, spinal column, and nervous system are almost complete and his eyes begin to form.
Day
22
His heart begins to beat.
Day
28
This little boy is now approximately 1/4 inch long - 10,000 times larger than he was only three weeks ago! The blood flowing in his veins is completely different than his mother's.
Week
4
His muscles are developing, and arms and leg buds are visible. His large, distinct head is clearly identifiable, along with the major outlines of brain and eye vesicles, the beginnings of his central nervous system, notochord, mouth and pharynx, body cavity, and the basis of his skeleton.
Week
5
Our little friend's face is taking shape; his forehead, eyes, nostrils and mouth are evident; external ears are beginning; hand and foot plates appear in his limb buds.
Week
6
The brainwaves of this little boy can be recorded. His different muscles begin working together.
Week
8
His fingers and toes are fairly well defined, and fingerprints, a unique and defining feature of every human being, are permanently engraved on his skin. All of his organs are present, complete, and functioning (except his lungs).
Weeks
9-10
All areas of his body are sensitive to touch. He sucks his thumbs, swallows, squints, frowns and puckers his brow. If his palm is stroked, he will make a tight fist.
Weeks
11-12
He now has fingernails, toenails and working taste buds. He can also make all facial expressions, including a smile.
Week
13
Although this baby was already a boy at fertilization, his sex is now identifiable.
Month
4
This little baby's heart is pumping six gallons of blood every day, and his mom can now feel him jumping around and turning somersaults, exercising the muscles and lungs he will need to live outside his mother's womb. Rapid eye movement (REM) can be recorded while he's sleeping, indicating that he is dreaming.
Months
5-6
He now weighs about one pound and is a foot long. If he is born now, he would have a 50 percent chance of surviving with the help of dedicated doctors and nurses.
Months
7-8
He can open and close his eyes and recognizes his mom's voice. His weight continues to increase and "baby fat" fills out and smoothes his skin. If he is born now, his chance of surving increases to 90 percent.
Month
9
When he is ready to be born, he will release hormones to trigger labor. He may weigh between 7 and 9 pounds, and can be between 18 and 21 inches long!