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 indivdual burrows into the wall of the womb. Sex can be determined.
14 Days-Mother's menstrual period is supressed by a hormone produced by her child.
18 Days-Heart is forming; eyes developing.
20 Days-Fondations of brain, spinal cord and nervous systems 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 long. Brain has human proportions. Blood flows in veins (but stays seperate 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, 3cm sitting up and a gram in weight. Every organ is present. Heart beats sturdily. Stomache produces digestive juices, Liver makes blood cells. Kidneys begin to function. Taste buds are forming.
9 Weeks-Child will bend fingers arouund an object placed in the palm. Thumb sucking occurs. Fingernails are formed.
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 apparant.
4 Months-Child can grasp with hands, swim and turn somersaults.
4-5 Months-Mother senses movement.
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 and height 23cm. 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 pounds) 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 devisions before adulthood, 41 have taken place.
Adapted from "Milestones Of Life". The milestones listed above have been documented by scientific research. Slight variations of hours or days may exist and future research may show that some milestones occur earlier than is now realized.