The Baby Inside

Facts on Fetal Development

Day 1 - conception takes place.

7 days - tiny human implants in mother’s uterus.

10 days - mother’s menses stop.

18 days - heart begins to beat.

21 days - pumps own blood through separate closed circulatory system with own blood type.

28 days - eye, ear and respiratory system begin to form.

42 days - brain waves recorded, skeleton complete, reflexes present.

7 weeks - photo of thumb sucking.

8 weeks - all body systems present.

9 weeks - squints, swallows, moves tongue, makes fist.

11 weeks - spontaneous breathing movements, has fingernails, all body systems working.

12 weeks - weighs one ounce.

16 weeks - genital organs clearly differentiated, grasps with hands, swims, kicks, turns, somersaults, (still not felt by the mother.)

18 weeks - vocal cords work – can cry.

20 weeks - has hair on head, weighs one pound, 12 inches long.

23 weeks - 15% chance of viability outside of womb if birth premature.

24 weeks - 56% of babies survive premature birth.

25 weeks - 79% of babies survive premature birth.

 

(Source: M. Allen et. al., "The Limits of Viability." New England Journal of Medicine. 11/25/93: Vol. 329, No. 22, p. 1597.)