What happens during the first trimester?

At four weeks:

  • Your baby’s brain and spinal cord have begun to form.
  • The heart begins to form.
  • Arm and leg buds appear.
  • Your baby is now an embryo and smaller than a grain of rice.

At eight weeks:

  • All major organs and body structures have started to form.
  • Your baby’s heart beats with a regular rhythm
  • The arms and legs grow longer, and fingers and toes have started to form.
  • Your baby’s sex organs have begun to form.
  • The eyes have moved forward on the face and eyelids have formed.
  • The umbilical cord can easily be seen.
  • At the end of eight weeks, your baby looks more like a human and is almost 1 inch long.

At 12 weeks:

  • Nerves and muscles are starting to work together and your baby can make a fist.
  • Your baby’s sex organs show on the outside, baby’s sex can be seen soon with an ultrasound.
  • The eyelids close to protect the eyes.
  • Your baby is about 3 inches long.