20 weeks pregnant
Second trimester about 4 months
At 20 weeks pregnant, your baby is about the size of a banana.
Baby this week
About 250mm head to toe. The anatomy scan this week provides a comprehensive view of all major organs. The baby is fully proportioned and looks recognizably like a newborn.
Did you know? The anatomy scan at 20 weeks can identify over 90% of major structural birth defects, making it one of the most important diagnostic appointments in prenatal care.
What she may be feeling
- Strong regular fetal movement
- Visible round belly
- Back pain
- Heartburn
- Braxton Hicks
- Swollen feet and ankles
- Stretch marks
- Increased vaginal discharge
Tips for her this week
- The anatomy scan checks all major organs, amniotic fluid, placenta position, and baby's measurements.
- This is the appointment where sex is usually confirmed if you want to know.
- At 20 weeks, you're exactly halfway through a 40-week pregnancy.
- Celebrate this milestone — it deserves recognition.
For partners
- The anatomy scan is one of the most significant appointments of the entire pregnancy — do not miss it.
- You'll see the baby's face, hands, heart chambers, and organs in detail. It's extraordinary.
- If there are any findings, stay calm — many are minor and need monitoring rather than action.
- You're at the halfway point. Take a moment to appreciate how far you've come.
Partner to-do list
- Attend the anatomy scan — this is non-negotiable
- Ask about placenta position, amniotic fluid levels, and any findings
- Celebrate the halfway point together
- Start assembling baby gear: car seat, stroller, bassinet
This week together
- Celebrate the halfway point meaningfully
- Confirm sex if you choose to know
- Schedule follow-up if any findings at the scan
- Finalize nursery — you now have 20 weeks left
When to call your doctor or midwife
Contact your care provider right away, or call emergency services, if she has:
- Placenta previa detected (placenta covering cervix — needs monitoring)
- Heavy bleeding
- Severe pain
- Fever
- Signs of preterm labor
Trusted guidance: NHS: Pregnancy · NHS: Pregnancy complications · ACOG: Pregnancy · Pregnancy Info: Your pregnancy
Common questions
How big is the baby at 20 weeks?
At 20 weeks pregnant, your baby is about the size of a banana. About 250mm head to toe.
How many months is 20 weeks pregnant?
20 weeks pregnant is about 4 months, in the second trimester.
What can partners do at 20 weeks?
The anatomy scan is one of the most significant appointments of the entire pregnancy — do not miss it. You'll see the baby's face, hands, heart chambers, and organs in detail. It's extraordinary.