5 - 9 days

Gender can be determined.

18 days

Heart and eyes begin to develop.

18 - 24 days

Heart beats.

28 days

Muscles develop along spine. Arms and legs bud.

30 days

Blood flows through veins independent from mom's.

35 days

Pituitary gland forms. Mouth, ears and nose take shape.

40 days

Electronic brain waves have been recorded.

42 days

Skeleton is formed. Brain coordinates muscle & organ movement.

45 days

Milk teeth have budded.

7 weeks

Lips sensitive to touch.

8 weeks

Every organ present. Stomach produces digestive juices. Liver makes blood cells. Kidneys function. Taste buds form.

9 weeks

Grasps things in palm. Sucks thumb. Fingernails form.

10 weeks

Sensitive to touch. Squints, swallows and frowns.

11 weeks

Makes complex facial expressions including smiles.

12 weeks

Individuality reflected in activity. Kicks, turns feet, curls and fans toes, makes fists, moves thumbs, bends wrists, turns head, opens mouth and presses lips tightly together.

13 weeks

Vocal cords formed. Gender apparent.

4 months

Swims and turns somersaults.

5 months

Sleeping habits appear. Responds to sounds too high or low for adults. Good chance for survival outside of womb.

6 months

Fine hairs on eyebrows and head. Eyelash fringe appears.

7 months

Eye teeth present. Eye lids open and close. Eyes look around.

8 months

Size and weight increases.

9 months

Triggers labor at 255 to 275 days after conception. Of 45 generations of cell divisions before adulthood, have already taken place.

Conclusion:

The difference between a newborn and preborn is developmental only; just as there is a big difference between a two year old and a newborn.  Same beautiful blessing, different day.