Second trimester · Week 17 of 40
17 weeks pregnant: the size of a pear
Fat begins to form under the skin. The umbilical cord grows stronger.
Reviewed against ACOG, NHS and WHO guidance · Updated November 2026
Typical size
About 13 cm · 140 g
43% of the way to your due date
Your baby this week
Fat begins to form under the skin. The umbilical cord grows stronger.
Your body this week
Increased appetite is normal — you need only about 340 extra calories a day in the second trimester.
Tip for week 17
Choose nutrient-dense snacks like yogurt, nuts and fruit.
Carry this guide in your pocket
Mamivaa is a free pregnancy app with a week-by-week tracker, vitamin and water reminders, a food scanner and a baby checklist.
Start freeThis guide offers general information and does not replace advice from your doctor or midwife. If something feels wrong, contact your provider or emergency services.