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
 
Current as of: July 15, 2025