Quick answer: At week 10 your baby is officially a foetus, no longer an embryo, because all the major organs and structures have now formed and development shifts to growth. They measure roughly 31mm crown to rump, about the size of a strawberry. Fingers and toes are separated, the kidneys are producing urine, and your 12-week dating scan is approaching.
What parents need to know
Week 10 is a genuine milestone in your pregnancy journey. Your baby is no longer called an embryo — from this week, they are officially a foetus. This reflects the fact that all of the major structures and organs have now formed, and development is shifting from formation to growth and maturation.
| Baby's size | About 31mm crown to rump, like a strawberry |
|---|---|
| Dating scan window | Between 10 weeks and 14 weeks and 1 day |
| Maternity leave | Up to 52 weeks, regardless of length of service |
| Statutory Maternity Pay | 39 weeks: 6 at 90% earnings, then 33 at flat rate |
| Tell your employer | By 15 weeks before your due date to qualify for SMP |
How big is your baby at 10 weeks?
Your baby is now about the size of a strawberry — roughly 31mm from crown to rump. They have doubled in size in just two weeks and will continue to grow rapidly throughout your pregnancy.
What's happening with your baby?
Now officially a foetus, your baby has all their vital organs in place, even if they won't be fully functioning for some time. The kidneys are beginning to produce urine. The liver is already making red blood cells. Your baby's hands and feet are now recognisably formed, with fingers and toes fully separated. Tooth buds are appearing beneath the gum line. The intestines, which were temporarily in the umbilical cord, are beginning to move back into the abdomen as there is now more room. Your baby's genitals are beginning to develop, though it's still too early to determine sex by ultrasound.
Your baby is also swallowing amniotic fluid and is making small, jerky movements, though these are still far too small for you to feel.
What's happening in your body?
You may be nearing the end of the worst of your first trimester symptoms. For many women, nausea begins to ease around weeks 12 to 14 as hCG levels plateau, though for some it persists for longer. Fatigue often remains. You might notice your bump is not yet visible, but your clothes may be feeling tighter, particularly around the waist. This is partly due to a growing uterus and partly due to bloating and water retention.
Round ligament pain — a sharp or stretching pain on one or both sides of your lower abdomen — can begin in the first trimester as your uterus expands and the ligaments supporting it stretch. This is entirely normal, though mention it to your midwife if it is severe or if you're unsure what's causing the discomfort.
Preparing for your 12-week scan
Your 12-week dating scan is approaching. This scan, which usually takes place between 10 weeks and 14 weeks and 1 day, serves several important purposes. It confirms your due date by measuring your baby's crown-to-rump length. It checks for a heartbeat and looks at your baby's anatomy at this early stage. It also offers combined screening for chromosomal conditions including Down's syndrome, Edwards' syndrome, and Patau's syndrome.
Combined screening involves a blood test (checking levels of pregnancy hormones) and a measurement of the fluid at the back of your baby's neck (called the nuchal translucency measurement). Together, these give a risk assessment. Accepting or declining this screening is entirely your choice; your midwife will explain the options clearly.
You'll be asked to drink water before the scan to give a clearer image, and the sonographer will apply gel to your abdomen and use an ultrasound probe to view your baby on a screen. Many parents find this their first truly joyful moment of the pregnancy journey.
Thinking about work and maternity leave
Although your maternity leave doesn't start until much later in pregnancy, it's worth starting to think about your rights and options. In the UK, you are entitled to up to 52 weeks of maternity leave regardless of how long you have worked for your employer. Statutory Maternity Pay (SMP) lasts for 39 weeks: the first six weeks are paid at 90% of your average weekly earnings, and the remaining 33 weeks at the statutory flat rate (which changes each April). You must inform your employer of your pregnancy by 15 weeks before your due date to qualify for SMP.
Your week 10 checklist
This week:
- Make sure your 12-week scan is booked.
- Review NHS guidance on your screening options.
- Continue your daily supplements.
- Think about maternity leave entitlements and when to inform your employer.
- Celebrate this milestone — your baby is officially a foetus.
Sources & further reading
- NHS — You and Your Baby at 10 Weeks Pregnant
- NHS — Screening Tests in Pregnancy
- Tommy's — Week 10 of Pregnancy
- Maternity Action — Your Maternity Rights
General information, not individual medical advice. Speak to your GP, midwife or health visitor about your baby’s needs.
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