Week 12 of Pregnancy: What’s Going On Inside

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Week 12 of Pregnancy: What's Going On Inside

Overview

By week 12, you can now hear a fetus's heartbeat with a Doppler heart monitor.

Wondering what a fetus looks like at 12 weeks? It is now about the size of a lime.

How a fetus is changing

Here are some important changes that happen around this time.

  • By 10 weeks of pregnancy, an embryo has nearly all of the body structures that adults have. Its brain is now more complex. After this point, we call it a fetus.
  • During this month, the fetus's limbs, hands, and head start to move. Eyelids cover their eyes, and their fingernails are starting to grow.
  • At the end of this month, fetuses start a big weight gain.

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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