Fetal Development

Unborn baby's feet at 10 weeks
after conception

Unborn baby at 8 weeks

Day 1 - conception takes place.
Day 7 - tiny human implants in mother’s uterus.
Day 10 - mother’s menses stop.
Day 18 - heart begins to beat.
Day 21 - pumps own blood through separate closed circulatory system with own blood type.
Day 28 - eye, ear and respiratory system begin to form.
Day 42 - brain waves recorded, skeleton complete, reflexes present.
Week 7 - photo of thumbsucking.
Week 8 - all body systems present.
Week 9 - squints, swallows, moves tongue, makes fist.
Week 11 - spontaneous breathing movements, has fingernails, all body systems working.
Week 12 - weighs one ounce.
Week 16 - genital organs clearly differentiated, grasps with hands, swims, kicks, turns, somersaults, (still not felt by the mother.)
Week 18 - vocal cords work – can cry.
Week 20 - has hair on head, weighs one pound, 12 inches long.
Week 21 - youngest child to survive outside womb after premature birth
Week 23 - 17% chance of viability outside of womb if birth premature.*
Week 24 - 39% of babies survive premature birth.*
Week 25 - 50% of babies survive premature birth.*

Additional Resources: Facts of Fetal Development High definition images of week by week development of baby in utero Fetal Development Movie Theater Videos following the growth and fetal development from conception through birth.