How accurate is a due date?

A due date is an estimate. Only about 1 in 20 babies arrive on it; most are born within two weeks either side.

Can my due date change?

Yes — early ultrasound measurements can refine it. Later scans usually do not shift an established date.

Are these baby-size comparisons exact?

The fruit and vegetable comparisons are friendly approximations of average length. Every pregnancy is unique — your baby may be a little larger or smaller.

Week 17 of pregnancy

17 Weeks Pregnant

Second trimester

Baby size

About the size of a pear

13 cm

What's developing

Fat is starting to develop under the skin. The baby's skeleton is transitioning from cartilage to bone.

Common symptoms this week

Vivid dreams
Occasional dizziness
Increased appetite
Belly stretching

This is an estimate for information only — only about 1 in 20 babies arrive on their due date. Always confirm dates with your midwife or doctor.

How big is a baby at 17 weeks?

Baby growth chart

Typical fetal length and weight from week 8 to week 40.

Weeks 8–40

Length

Week 17: 13.0 cm

Weight

grams

Week 17: 140 g

Typical averages based on Hadlock / ACOG references. Weeks 8–20 use crown–rump length; weeks 21–40 switch to crown–heel — that's the small jump you'll see mid-chart. Real babies vary — your ultrasound is the reliable number for you.55

Frequently asked questions

Jump to another week

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40