17 Weeks Pregnant: Baby Size, Symptoms and UK Milestones
At 17 weeks pregnant, use this UK guide to understand baby size, common symptoms, likely NHS timing, and the practical dates to keep on your radar.
17 weeks pregnant at a glance
- You are in the second trimester.
- Your baby is roughly the size of a pear.
- Routine care.
- Every pregnancy is different, so don't worry if your experience varies slightly.
You are 17 weeks pregnant and in your second trimester. Your baby is about the size of a pear. This week's key development: Growing Strong. NHS note: Routine care.
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.
Baby's Development
Your baby is about the size of a pear.
Growing Strong — Fat is beginning to accumulate under your baby's skin, which will help regulate their temperature after birth. Their skeleton continues to harden, and the umbilical cord is growing thicker and stronger — the lifeline between you two.
Your Symptoms
- Increased sweating
- Itchy skin on your belly
- Stretch marks may appear
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
Routine care. Your next big milestone is the 20-week anomaly scan.
Practical Advice for Week 17
Nutrition
- Continue vitamin D and eat a varied, balanced diet.
- Omega-3 fatty acids support your baby's brain development — include oily fish or supplements.
- If heartburn is starting, avoid spicy or fatty foods close to bedtime.
- Magnesium-rich foods (bananas, dark chocolate, almonds) may help with leg cramps.
Exercise
- Continue moderate exercise — your body will tell you what feels right.
- Gentle stretching helps with the itchy, stretching skin on your belly.
- Swimming relieves pressure on your joints and back.
- Avoid lying flat on your back during exercise — use an incline instead.
Wellbeing
- Itchy skin on your belly is normal as it stretches — moisturise liberally.
- Stretch marks may appear — they're a badge of honour, and they fade over time.
- Increased sweating is caused by higher metabolism and blood flow.
- Use a pregnancy-safe moisturiser or oil on your bump — coconut oil or bio-oil are popular.
Preparation
- Your next big milestone is the 20-week anomaly scan — check it's booked.
- Start looking at pushchairs and car seats — research takes time.
- Consider whether you want to find out your baby's sex at the 20-week scan.
- If you haven't told your employer yet, you must do so by 15 weeks before your due date.
Tip of the Week
Use a moisturiser or oil on your growing bump to help soothe itchy, stretching skin.
Frequently Asked Questions for Week 17
How many months is 17 weeks pregnant?
What size is the baby at 17 weeks?
What are the common symptoms at 17 weeks pregnant?
Is 17 weeks in the second trimester?
Are there any NHS appointments at 17 weeks?
Tools & Calculators
Sources and further reading
Checked for UK week 17 pregnancy information guidance in July 2026.
- NHS Pregnancy Guidance
- NHS: Ultrasound scans in pregnancy
- NHS Start for Life: Pregnancy
- RCOG patient information
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.
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