Life Before Birth

YOUR FIRST NINE MONTHS of life were the most eventful you have ever experienced. Here are the major milestones of that life before birth - the first chapter in your own biography.

CONCEPTION: Father's sperm penetrates mother's egg cell. Genetic instructions from parents interact to begin a new and unique individual - no bigger than a grain of sugar.
1st DAY: The first cell divides into two, the two into four, and so on.
5-9 DAYS: The new individual burrows into the wall of the womb. Sex can be determined.
14 DAYS: Mother's menstrual period is suppressed by a hormone produced by her child.
18 DAYS: Heart is forming; eyes developing.
20 DAYS: Foundations of brain, spinal cord and nervous system are laid.
24 DAYS: Heart begins to beat.
28 DAYS: Muscles are developing along the future spine. Arms and legs are budding.
30 DAYS: Child has grown 10,000 times to 6-7mm. (1/4 in.) long. Brain has human proportions. Blood flows in veins (but stays separate from mother's blood.
35 DAYS: Pituitary gland in brain is forming. Mouth, ears and nose are taking shape.
40 DAYS: Heart's energy output is 20 percent of adult's.
42 DAYS: Skeleton is formed. Brain coordinates movement of muscles and organs. Reflex responses have begun. Penis is forming in boys. (Mother misses second period.)
43 DAYS: Brain waves can be recorded.
45 DAYS: Spontaneous movements have begun. Buds of milk teeth have appeared.
7 WEEKS: Lips are sensitive to touch. Ears may resemble family pattern.
8 WEEKS: Child is well-proportioned, small-scale baby, 3 cm. (1 1/8 in.) sitting up and a gram (1/30 oz.) in weight. Every organ is present. Heart beats sturdily. Stomach produces digestive jiuces. Liver makes blood cells. Kidneys begin to function. Taste buds are forming.
9 WEEKS: Child will bend fingers around an object placed in the palm. Thumb sucking occurs. Fingernails are forming.
10 WEEKS: Body is sensitive to touch. Child squints, swallows and frowns.
11 WEEKS: Baby urinates, makes complex facial expressions - even smiles.
12 WEEKS: Vigorous activity shows distinct individuality. Child can kick, turn feet, curl and fan toes, make a fist, move thumbs, bend wrists, turn head, open mouth and press lips tightly together. Breathing is practiced.
13 WEEKS: Face is prettier, facial expressions resembling parents'. Movements are graceful. Vocal cords are formed (but without air baby cannot cry). Sex organs are apparent.
4 MONTHS: Child can grasp with hands, swim and turn somersaults.
4-5 MONTHS: Mother senses movements.
5 MONTHS: Sleeping habits appear. Child responds to sounds in frequencies too high or low for adults to hear.
6 MONTHS: Fine hair grows on eyebrows and head. Eyelash fringe appears. Weight is about 640g. (1 lb. 6 oz.) and height 23 cm. (9 in.). Babies born at this age have survived.
7 MONTHS: Eye teeth are present. Eyelids open and close, eyes look around. Hands grip strongly. Mother's voice is recognized.
8 MONTHS: Weight increases by 1kg. (over 2 lbs.) and baby's quarters get cramped.
9 MONTHS: Child triggers labor and birth occurs, usually 255-275 days after conception. Of 45 generations of cell divisions before adulthood, 41 have already taken place.