DueDate.Baby

20 Weeks Pregnant: Baby Size, Symptoms and UK Milestones

Second Trimester
Guide reviewed: July 2026Reviewed against cited UK guidance

At 20 weeks pregnant, use this UK guide to understand baby size, common symptoms, likely NHS timing, and the practical dates to keep on your radar.

20 weeks pregnant at a glance

  • You are in the second trimester.
  • Your baby is roughly the size of a banana.
  • Mid-pregnancy anomaly scan.
  • Every pregnancy is different, so don't worry if your experience varies slightly.

You are 20 weeks pregnant and in your second trimester. Your baby is about the size of a banana. This week's key development: Halfway. NHS note: Mid-pregnancy anomaly scan.

20-week scan timing

Estimate the usual anomaly scan window, which is commonly planned around 18 to 21 weeks of pregnancy.

UK maternity leave dates

Use your due date to estimate maternity leave notice, MATB1, and earliest usual leave-start dates.

This page is for general pregnancy planning and date guidance only. It is not medical advice, diagnosis, or treatment. Pregnancy dates are estimates and can change after a scan or advice from your midwife, GP, or maternity team.

If you have symptoms, concerns, or questions about your pregnancy, speak to your midwife, GP, or maternity team. For urgent help, use NHS 111; call 999 in an emergency. Read how we source and review content in our editorial policy.

Previous
Week 19
Next
Week 21

Baby's Development

Your baby is about the size of a banana.

Halfway — You've reached the midpoint of your pregnancy. Your baby's movements are becoming stronger and more frequent. Many parents have their mid-pregnancy anatomy scan around now — a chance to see your baby in wonderful detail.

Illustration of a banana, showing the approximate size of the baby at week 20
Banana
Approx. 25.6cm

Your Symptoms

  • Stronger kicks
  • Heartburn
  • Shortness of breath

Every pregnancy is different. You may experience all, some, or none of these symptoms — and that's completely normal. If anything concerns you, speak to your midwife.

NHS Appointments

Mid-pregnancy anomaly scan. This is often when you can find out the sex if you wish.

Practical Advice for Week 20

Nutrition

  • Continue vitamin D daily.
  • You're halfway — celebrate with a nutritious but delicious meal!
  • Iron needs increase in the second half of pregnancy — eat red meat, beans, and dark greens.
  • Include healthy carbohydrates for energy — sweet potatoes, brown rice, quinoa.

Exercise

  • Continue moderate exercise — 150 minutes per week is the NHS target.
  • Swimming becomes increasingly comfortable as your bump grows.
  • Pelvic floor exercises are essential — they help with labour and recovery.
  • Avoid high-impact exercise if you experience any pelvic or back pain.

Wellbeing

  • Stronger kicks are a wonderful reassurance — enjoy the feeling of your baby moving.
  • Heartburn may become more persistent — eat smaller meals and avoid lying down after eating.
  • Shortness of breath is normal as your uterus pushes against your diaphragm.
  • Celebrate this milestone — you're halfway through your pregnancy!

Preparation

  • Your mid-pregnancy anomaly scan — you may find out the sex if you wish.
  • Start thinking about your birth plan in more detail.
  • Research antenatal classes if you haven't booked yet — NHS ones are free.
  • If this is your first baby, consider touring your local birth centre or hospital.

Tip of the Week

Celebrate! You're halfway through this incredible journey.

Frequently Asked Questions for Week 20

How many months is 20 weeks pregnant?
At 20 weeks pregnant, you are roughly 4 months pregnant. Remember that pregnancy is typically measured in weeks rather than months for clinical accuracy.
What size is the baby at 20 weeks?
At 20 weeks, your baby is roughly the size of a banana (about 25.6cm). You've reached the midpoint of your pregnancy. Your baby's movements are becoming stronger and more frequent. Many parents have their mid-pregnancy anatomy scan around now
What are the common symptoms at 20 weeks pregnant?
Common symptoms at this stage include stronger kicks, heartburn, shortness of breath. Remember that every pregnancy is unique, and it's normal to experience different symptoms.
Is 20 weeks in the second trimester?
Yes, 20 weeks falls within the second trimester.
Are there any NHS appointments at 20 weeks?
Mid-pregnancy anomaly scan. This is often when you can find out the sex if you wish.
What happens at the 20-week scan?
The 20-week anomaly scan is a detailed ultrasound that checks the physical development of your baby.
Can I feel movement at 20 weeks?
Many women start feeling definite movements, called quickening, between 16 and 24 weeks.
Is 20 weeks halfway through pregnancy?
Yes, standard pregnancy is measured as 40 weeks, making 20 weeks the halfway point.

Tools & Calculators

Due Date Calculator UKPregnancy Week CalculatorTimeline by Due DateHow Many Weeks Am I?20-Week Scan CalculatorMaternity Leave Calculator UK

Sources and further reading

Checked for UK week 20 pregnancy information guidance in July 2026.

How we review content

We prioritise official NHS and GOV.UK guidance, then relevant professional-body information where needed.

Source links are checked on the review date shown above. Your midwife, GP, maternity team, fertility clinic, or employer can give advice that is more specific to your circumstances.

Previous
Week 19
Next
Week 21

Track Your Due Date

Keep track of your pregnancy milestones, NHS scans, and countdown to your due date.

Go to Tracker

NHS Resources

Find trusted information on financial support, antenatal classes, and local maternity services.

View Resources

All Weeks

Browse the complete week-by-week pregnancy guide from conception to birth.

View All Weeks

Loading guide...