How Your Baby Grows

To get a rough idea of when your baby is due visit Due Date Calculator (SOGC).
Your due date is a best guess – most babies are born within two weeks before or after your due date.

The FIRST trimester (Weeks 1 to 12)

By the end of the first trimester:

• The placenta, the umbilical cord, and all of baby’s organs have formed.
• Baby’s heart is beating. The heartbeat can be detected by ultrasound at around 6 weeks.
• The face is forming and includes ears, a nose, and eyes which are closed.
• The arms, legs, fingers, and toes have appeared.
• The brain is growing quickly.

The SECOND trimester (Weeks 13 to 27)

By the end of the second trimester:

• The external genitals are well developed.
• Baby’s eyes can open and sense light.
• Other senses develop – your baby can hear!
• The heartbeat can be heard by your health care provider using a hand-held device called a doppler.
• Baby is using muscles to move and kick.
• Baby can have hiccups.
• Baby is able to suck and you may even find him sucking his thumb on an ultrasound!
• Baby is covered with a protective white cream (vernix) and fine hairs (lanugo).
• The lungs are developed but not able to function yet.

The THIRD trimester (Weeks 28 to Birth)

By the end of the third trimester:

• The skin becomes less wrinkled as baby gains weight more quickly.
• Baby won’t be doing somersaults anymore but you should still feel frequent movement.
• Baby sleeps and wakes regularly.
• The lungs and brain mature.
• Baby usually turns into a head-down position for birth.

Conception to Birth Visualized (fragment) TED Talk