Prenatal Development

  • Month 1

    The size of a pin head.
    Critical stage for brain and spinal cord development.
    Internal organs and circulatory system begin to form.
    The heart begins to beat.
  • Month 2

    About 1/4 inch long.
    Face, eyes, ears, and limbs take shape.
    Bones begin to form.
  • Month 3

    About 1 inch long.
    Nostrils, mouth, lips, and eyelids form.
    Buds for all 20 baby teeth appear.
    Fingers and tows almost complete.
    All organs present but still immature.
  • Month 4

    About 3 inches long, weighs 1 ounce.
    Can suck its thumb, swallow, hiccup, and move around.
    Facial features become clearer.
  • Month 5

    About 6 1/2-7 inches long, weighs about 4-5 ounces.
    Hair, eyelashes, and eyebrows appear.
    Teeth continue to develop.
    Organs are maturing.
    Becomes more active.
  • Month 6

    About 8-10 inches long, weighs about 8-12 ounces.
    Fat deposits under skin, but fetus appears wrinkled.
    Breathing movements begin.
  • Month 7

    About 10-12 inches long, weighs about 1 1/2-2 pounds.
    Has periods of activity followed by periods of rest and quiet.
  • Month 8

    About 14-16 inches long, weighs about 2 1/2-3 pounds.
    Rapid weight gain.
    May react to loud noises with a reflex jerking action.
    Move into a head-down position.
  • Month 9

    About 17-18 inches long, weighs about 5-6 pounds.
    Weight gain continues.
    Skin becomes smooth as fat deposits continue.
    Movements decrease as the fetus has less room to move around.
    Acquires disease-fighting antibodies from the mother's blood.
    Descends into pelvis, ready for birth.