The second trimester is a very moving time, both literally and figuratively. Your belly is starting to show evidence of your growing uterus, you are feeling your baby move, and you may even find out the sex of your baby if you so choose. While your body goes through many changes, your baby is also growing at a rapid pace. In the second trimester, your baby is about 2.5 pounds and develops bones, genitals, hair, and even ever-so-tiny footprints.

Weeks 13-17

Now that you are in your second trimester of pregnancy, your baby has defined fingers and toes, hair, eyebrows, eyelashes, bones, teeth, and nails. Your baby has even started to make motions like making faces, yawning, and sucking its thumb. The earliest you may be able to tell your baby’s sex is in week 14, though many don’t find out until week 17 or later. In week 15, your baby’s bones become denser and are visible through the ultrasound. Week 16 is the early stage of your baby learning to suck his or her thumb and in week 17, fat starts accumulating. Your baby can hear near the end of month four. Your baby is about six inches long now.

Weeks 18-22

Around week 18 or week 19, your baby’s hair is growing more rapidly and since he or she is starting to move, you feel movements clearly during this time. If you are having a girl, her uterus typically forms in week 19. Week 20 marks your pregnancy’s halfway point, which is when quickening (baby movements) begins. If this isn’t your first pregnancy, you may have already felt some flutters. In week 21 and week 22, your baby learns to swallow and is generally more active.

Weeks 23-26

Your baby starts to hiccup, has visible veins and their eyes begin opening. Around week 24, your baby is waking up and sleeping in regular intervals. By week 25, your bundle of joy can not only hear your voice but respond to it. Fingernails are developed in week 26, and in week 27, your baby’s nervous system and lungs are beginning to mature. Your baby is now about 12 inches long. He or she weighs about 2 pounds to 2.5 pounds at the end of your second trimester.

Second-trimester tools, calculators, and quizzes

Is it a Boy or a Girl? Predict the Baby's Sex
Baby Eye Color Predictor 
Weight Change Calculator
BMI Body Mass Calculator
How Safe Are These Beauty Routines During Pregnancy?
Which Activities Are Safe During Pregnancy?
What is a Healthy Fertility and Pregnancy Diet?

Second trimester by the week

Week 14 Week 15 Week 16

Week 17

Week 18 Week 19
Week 20 Week 21 Week 22
Week 23 Week 24  Week 25
Week 26 Week 27  

What you need to know about your second trimester

Second Trimester Checklist
How to Survive the Second Trimester of Pregnancy in 12 Steps
What Happens in the Second Trimester of Pregnancy with my Body?
What Happens in the Second Trimester of Pregnancy with my Baby?
What Happens in the Second Trimester of Pregnancy with my Doctor's Appointments and Tests?
What Happens in the Second Trimester of Pregnancy with my Relationship?
The Second Trimester from the Male's Perspective
Second Trimester Miscarriage

All pregnancy trimesters

  1. Pre-Trimester (preconception)
  2. First Trimester (up to 12-13 weeks)
  3. Second Trimester (up to 26-27 weeks)
  4. Third Trimester (up to delivery)
  5. Fourth Trimester (postbirth or postpartum)
  6. Fifth Trimester (going back to work)