12 Weeks Pregnant: Baby Size, Symptoms and UK Milestones
At 12 weeks pregnant, use this UK guide to understand baby size, common symptoms, likely NHS timing, and the practical dates to keep on your radar.
12 weeks pregnant at a glance
- You are in the first trimester.
- Your baby is roughly the size of a plum.
- Dating scan and combined screening test (if chosen) usually happen this week.
- Every pregnancy is different, so don't worry if your experience varies slightly.
You are 12 weeks pregnant and in your first trimester. Your baby is about the size of a plum. This week's key development: Almost Out of Hiding. NHS note: Dating scan and combined screening test (if chosen) usually happen this week.
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.
Week 12: scans, screening and practical next steps
In England, the NHS dating scan is usually offered at around 10 to 14 weeks. It checks how far along the pregnancy is and can be part of screening for Down's syndrome. Your maternity team will confirm what is offered locally and when your appointment will be.
If you have been taking 400 micrograms of folic acid, NHS guidance says to take it until the end of the first 12 weeks. Vitamin D advice varies by season and individual circumstances, so check the NHS guidance or ask your midwife, GP or pharmacist what applies to you.
You may also be starting to think about work and leave. You do not have to make every decision now, but GOV.UK sets notice deadlines for maternity leave and pay. Our calculator can turn your due date into a practical planning timeline.
Baby's Development
Your baby is about the size of a plum.
Almost Out of Hiding — Your baby can open and close their fists, and the digestive system is beginning to practise moving. Most major organ systems are in place. You're approaching the end of the first trimester — the time many families choose to share their happy news.
Your Symptoms
- Nausea may start to lift
- Increased energy
- Clearer skin for some
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
Dating scan and combined screening test (if chosen) usually happen this week.
Practical Advice for Week 12
Nutrition
- You can stop taking folic acid after this week — but continue vitamin D throughout pregnancy.
- Nausea may be easing — enjoy re-discovering foods you love.
- Ensure you're eating enough protein (meat, fish, eggs, beans, lentils) for your baby's growth.
- Drink water consistently throughout the day.
Exercise
- As energy returns, you may feel ready to exercise more — listen to your body.
- Swimming is wonderful in the second trimester as your bump grows.
- Continue pelvic floor exercises — make them a daily habit.
- Consider a structured pregnancy fitness programme if you enjoy having a plan.
Wellbeing
- Many parents choose to share their news after the dating scan — do what feels right for you.
- Nausea easing can feel like a relief but also bring anxiety — both reactions are normal.
- This is a natural time to feel a burst of optimism — enjoy it.
- If you've been struggling with sickness, be kind to yourself — the first trimester is hard.
Preparation
- Your dating scan and combined screening test (if chosen) usually happen this week.
- Apply for your Maternity Exemption Certificate (MatEx) for free NHS prescriptions and dental care.
- Tell your employer you're pregnant when you're ready — legally you must tell them by 15 weeks before your due date.
- Start researching maternity pay — check if you qualify for SMP or Maternity Allowance.
Tip of the Week
You can now apply for your Maternity Exemption Certificate (MatEx) for free prescriptions and dental care.
Frequently Asked Questions for Week 12
How many months is 12 weeks pregnant?
What size is the baby at 12 weeks?
What are the common symptoms at 12 weeks pregnant?
Is 12 weeks in the first trimester?
Are there any NHS appointments at 12 weeks?
Is 12 weeks the end of the first trimester?
When is the 12-week scan in the UK?
Can symptoms ease at 12 weeks pregnant?
Tools & Calculators
Sources and further reading
Checked for UK week 12 pregnancy information guidance in July 2026.
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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Keep track of your pregnancy milestones, NHS scans, and countdown to your due date.
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