First Trimester

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 - thumbsucking

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

Second Trimester

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 born premature*

Third Trimester

24 weeks - 56% of babies survive premature birth

25 weeks - 79% of babies survive premature birth