First trimester: What's happening

First trimester: What's happening

This section covers the physical and emotional changes you can expect during the first trimester of pregnancy.

  • Find out what's happening to you and your baby.
  • Learn what you need to know to make good choices for both of you. 
Illustration of pregnant body in first trimester

Your body is growing a placenta, adding breast tissue, increasing blood volume, making amniotic fluid, and creating a baby.

Source: Allina Health Patient Education, Beginnings: Pregnancy, Birth and Beyond, eighth edition, ob-ah-90026
First Published: 10/04/2002
Last Reviewed: 12/06/2021