Fetal Development in Third Trimester

Two trimesters down, one to go! Find out what developmental changes baby goes through in the home stretch.
profile picture of Erin Walters
ByErin Walters
Updated
May 2017
Hero Image

In the third trimester (weeks 28 through delivery), most major development has already happened. This is the time for baby to hang around gaining weight—about half a pound each week, at least until week 37.

Baby is still kicking and stretching, though her movement might slow down as she gets more cramped in the tight space of your belly. The coating of fine hair on her body (called lanugo) sheds away and the bones get nice and hard—except the skull, which stays soft and flexible for the big squeeze through your birth canal.

Related Video

Watch How Your Organs Make Room for Baby

Anisa Arsenault
Associate Editor
Published
02/24/2017

Congenital Heart Defects

Jennifer L.W. Fink
Registered Nurse

Why Your Baby Is Really Kicking in the Womb, According to New Research

Stephanie Grassullo
Associate Editor
Published
11/30/2018

New Study Confirms Newborns Are Super Smart

Ashley Edwards Walker
Contributing Writer
Published
12/13/2017

Study: Industrial Chemicals Pass From Mother to Fetus Throughout Pregnancy

Stephanie Grassullo
Associate Editor
Published
01/31/2019
Advertisement