18 Weeks Pregnant

At 18 weeks pregnant, your baby is about the size of a pear.

Length
13 cm (5.1 in)
Weight
140 g (5 oz)
Trimester
Second
Month
Month 5
Weeks to go
22

Size of a pear

Your baby at 18 weeks

Still about the size of a pear, your baby's ears are now in their final position, and they may begin to hear sounds like your heartbeat and voice. Nerves are being coated in protective myelin.

Your body at 18 weeks

You may feel more movement now. Lower blood pressure can make you dizzy if you stand up too fast.

Common symptoms at 18 weeks pregnant

  • Dizziness
  • Leg cramps
  • Swollen feet
  • Back pain

Every pregnancy is different. Having none of these symptoms is normal too.

Tips for week 18

  • Your anatomy scan may be scheduled between 18 and 22 weeks; it checks the baby's organs, growth and placenta position.
  • Stretch your calves before bed to help with leg cramps.
  • Talk and sing to your baby; they are starting to hear you.

Your week 18 checklist

  • Anatomy scan (18 to 22 weeks)
  • Stretch your calves before bed
  • Talk and sing to your baby

Helpful at 18 weeks

18 Weeks Pregnant: your questions answered

How big is a baby at 18 weeks pregnant?

At 18 weeks your baby is about the size of a pear: around 13 cm (5.1 in) long and weighing about 140 g (5 oz). Every baby grows at their own pace.

How many months is 18 weeks pregnant?

18 weeks pregnant is month 5 of your pregnancy, in the second trimester. Your due date is 22 weeks away.

What happens at the anatomy scan?

A detailed ultrasound checks your baby's brain, heart, spine, limbs, organs and growth, plus the placenta and amniotic fluid. You can usually find out the sex if you want to.

Sources

This guide is written from public guidance by the American College of Obstetricians and Gynecologists (ACOG), the NHS, the CDC and the World Health Organization. Baby sizes are averages; your baby may be bigger or smaller and still perfectly healthy.

General information only, not medical advice.

History of updates
  • : Added a weekly checklist and common questions.
  • : Matched fruit, length and weight to the Prego app.
  • : Published.

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