First Trimester: Months 1-3
1. Heart, brain, and lungs form (1st month)
2. Arms, fingers, and legs form and heart starts beating (2nd month)
3. Fetus can move around (3rd month)
Second Trimester: Months 4-6
1. Facial features form (4th month)
2. Eyelashes and nails form, heartbeat is heard (5th month)
3. Fetus can kick, open, close its mouth and swallow and hears sounds (6th month)
Third Trimester: Months 7-9
1. Arms and legs can move freely, eyes open (7th month)
2. Hair becomes longer (8th month)
3. Body organs have developed the ability to function on their own (9th month)