Week 20 of Pregnancy: What’s Going On Inside

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Week 20 of Pregnancy: What's Going On Inside

Overview

By week 20, you've probably felt your baby move. It may not feel like an obvious kick—yet! Instead, your baby's first movements might feel like "butterflies" or gas bubbles.

Wondering what your baby looks like at 20 weeks? Your baby is now about the size of a red pepper. Average baby length is 6.3 in. (160 mm).

How your baby is changing

Here are some of the important facts and developments around 20 weeks.

  • This is a time of very rapid growth, especially from 15 to 18 weeks of pregnancy.
  • By now, babies' heads are no longer so big compared to the rest of their body.
  • You can see bones on ultrasound by the end of week 17.
  • At this size, your baby is still small enough to change position a lot—from head-down to feet-down, or even sideways.
  • If this is your first pregnancy, you will start to feel your baby move. The first flutters you feel are called "quickening."
  • At the end of this month, your baby starts building up body fat.

Credits

Current as of: July 15, 2025

Author: Ignite Healthwise, LLC Staff
Clinical Review Board
All Ignite Healthwise, LLC education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.

Current as of: July 15, 2025

Author: Ignite Healthwise, LLC Staff

Clinical Review Board
All Ignite Healthwise, LLC education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.

This information does not replace the advice of a doctor. Ignite Healthwise, LLC, disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. Learn how we develop our content.

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