Skip to content

Health & Pregnancy

Font Size

Twins Development 2nd Trimester Highlights

By now, you may know the sex of your babies. They already have eyebrows. Even more exciting, your twins can recognize your voice!  At the end of this trimester, your twins have:

  • Fully formed organs that continue to grow.
  • Hard skeletons. 
  • Hearts beating 100 pints of blood a day. 
  • Ears that can hear sounds and know your voice.
  • Genitalia that can be seen and the sex determined.
  • Fully formed lungs not yet ready to breathe in air.
  • Early development of bronchioles, the airways of the lungs. Differentiation is still taking place.
  • Vernix, a waxy, waterproof material that covers and protects the babies' skin.
  • Fully formed hands and feet that are often put in the babies' mouths.
  • Brown fat, which helps produce heat to keep your babies warm. 
  • Hair and eyebrows on the babies' heads.
  • Soft, downy hair called lanugo that covers the babies' bodies to provide warmth. 
  • Ovaries in girl babies. 
  • Testes are still in a baby boy's abdomen. 
  • Fully formed fingers and toes with fingerprints. 
  • Very active brains -- even in sleep.
  • Cute chubby cheeks.

 

WebMD Medical Reference

Reviewed by Nivin Todd, MD on July 25, 2014

Pregnancy Week-By-Week Newsletter

Delivered right to your inbox, get pictures and facts on
what to expect each week of your pregnancy.

Today on WebMD

hand circling date on calendar
Track your most fertile days.
woman looking at ultrasound
Week-by-week pregnancy guide.
 
Pretty pregnant woman timing contaction pains
The signs to watch out for.
pregnant woman in hospital
Are there ways to do it naturally?
 
slideshow fetal development
Slideshow
pregnancy first trimester warning signs
Article
 
What Causes Bipolar
Video
Woman trying on dress in store
Slideshow
 
pregnant woman
Article
Close up on eyes of baby breastfeeding
Video
 
healthtool pregnancy calendar
Tool
eddleman prepare your body pregnancy
Video