20 Weeks Pregnant
Reviewed by Safi Allah Khan
Medically reviewed by: Safi Allah Khan · Written by the Momi team · Last updated 20 October 2026
Quick answer: At 20 weeks pregnant, your baby is about the size of a banana, about 25 cm (10 in) from head to heel. You're in the second trimester, in month 5, with 20 weeks to go until your due date. This week's milestone: anatomy scan window. Symptoms vary from person to person.
| Week 20 at a glance | |
|---|---|
| Trimester | Second |
| Month | 5 |
| Weeks to due date | 20 |
| Baby's size | About the size of a banana |
| Length | About 16.4 cm (6.5 in) crown to rump, or about 25 cm (10 in) head to heel |
| Weight | About 300 g (10.6 oz) |
| This week | Anatomy scan window |
Sizes are typical averages. Before about 20 weeks, length is measured crown to rump; after that, head to heel.
Your baby at 20 weeks
You're halfway. Your baby is about the size of a banana and weighs about 300 g (10.6 oz). From this week, babies are often measured from head to heel instead of crown to rump, which is why the length seems to jump.
Your body at 20 weeks pregnant
Your bump is likely showing. The top of your uterus is roughly at your belly button. Movements are getting easier to feel.
Things to do this week
- Have your 18 to 21 week anatomy (mid-pregnancy) scan if it's booked.
- Ask the sonographer anything you're unsure about.
- Start thinking about antenatal or childbirth classes.
When to call your doctor or midwife
Contact your care team straight away if:
- your baby's movements slow down or change once you've started feeling a pattern, or you haven't felt any movement by 24 weeks
- you have a severe headache, vision changes, pain just below your ribs, or sudden swelling of your face, hands or feet (possible signs of pre-eclampsia)
- you have regular contractions, pelvic pressure or a low, dull backache before 37 weeks
- you have bleeding or fluid leaking from your vagina
- you have a fever of 100.4°F (38°C) or higher
If something feels wrong, trust that feeling and call. In an emergency, call your local emergency number.
Track week 20 in Momi
Halfway is a good time for a bump photo and a diary entry in Momi. Momi follows your pregnancy week by week with your baby's size and development, and keeps your diary, bump photos, appointments, kick counts and contractions in one place.
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Keep reading
← 19 weeks pregnant · All weeks · 21 weeks pregnant →
Sources
- ACOG: Changes During Pregnancy (infographic)
- NHS: Your baby's movements
- NHS: Antenatal care and appointments
- CDC: Urgent Maternal Warning Signs
Medical disclaimer: Momi and this website provide general information, not medical advice. Always talk to your doctor or midwife; in an emergency call your local emergency number.
FAQ
How big is a baby at 20 weeks pregnant?
On average, a baby at 20 weeks is about the size of a banana: about 16.4 cm (6.5 in) crown to rump, or about 25 cm (10 in) head to heel, about 300 g (10.6 oz). These are typical averages, and healthy babies vary.
How many months is 20 weeks pregnant?
20 weeks pregnant is in the fifth month of pregnancy and the second trimester. Months don't divide evenly into 40 weeks, so different sources may label the month slightly differently.
What should I do at 20 weeks pregnant?
Have your 18 to 21 week anatomy (mid-pregnancy) scan if it's booked. Ask the sonographer anything you're unsure about.
Related guides
Track this in Momi
Momi is a free pregnancy tracker app for iPhone and Android that follows pregnancy week by week, estimates the due date, and keeps a pregnancy journal, weight log, kick counter and contraction timer in one place.
