Pregnancy Week 10: Your Baby Is Now a Foetus

8 min read

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. Your baby is no longer called an embryo: from this week, they're 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 for employees, regardless of length of service
Statutory Maternity Pay	39 weeks: 6 at 90% earnings, then 33 at the flat rate or 90% if lower
Tell your employer	At least 15 weeks before your due date (for maternity leave)

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've 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.

Cute baby crawling next to a plush horse toy on a white backdrop.

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 usually harmless. But call your maternity unit straight away if the pain is severe or does not go away after resting for 30 to 60 minutes, or if it comes with bleeding or spotting, regular cramping, lower back pain, unusual discharge or fluid leaking from your vagina, pain when you pee or needing to pee suddenly or more often, or pee that looks cloudy, pink, red or brown. At less than 20 weeks you may need to contact your GP or an early pregnancy unit instead, and if you cannot reach them, call NHS 111. Call 999 if you have severe tummy pain with any bleeding. Also call 999 or go to A&E if you have a sudden, sharp and intense pain in your tummy and feel very dizzy or faint, feel sick or look very pale, as this can be a sign of an ectopic pregnancy.

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, if you're an employee (not a 'worker'), 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) or 90% of your average weekly earnings, whichever is lower. To get SMP you must earn on average at least £129 a week and have worked for your employer continuously for at least 26 weeks into the 15th week before your due week. For maternity leave, tell your employer at least 15 weeks before your due date when your baby is due and when you want your leave to start. For SMP, give at least 28 days' notice of when you want it to start, plus proof of your pregnancy.

When to get help

Some symptoms in pregnancy can be a sign of something serious and need checking quickly. This is who to contact, and how soon.

Call 999 if:

you're bleeding from your vagina and the bleeding is heavy (soaking a period pad soon after putting it on), or you also have severe pain in your tummy, pain in your shoulder, or feel sick, faint, dizzy or lose consciousness
you have a sharp, sudden and intense pain in your tummy together with feeling very dizzy or fainting, feeling sick or looking very pale, as this could mean an ectopic pregnancy has ruptured (you can also go straight to A&E)
you have severe difficulty breathing (you're gasping, choking or not able to get words out) or your chest feels tight or heavy
you have pain and swelling in one leg and you also feel short of breath or have chest pain. A blood clot in the leg can travel to your lungs, which can be life-threatening
you have possible signs of sepsis, such as breathing very fast, being confused or having slurred speech, blue, pale or blotchy skin, a rash that does not fade when you press it, or a very high or very low temperature. Being pregnant makes sepsis more likely
you do not feel you can keep yourself safe (a mental health emergency is as serious as a physical one)

Always call 999 if you think it's a life-threatening emergency, no matter what stage of pregnancy you are.

Contact your GP or early pregnancy unit right away if:

you have light bleeding or spotting, even if you have no pain or only mild tummy pain
you have vaginal discharge that's unusual for you, or fluid leaking from your vagina
you have tummy pain low down on one side, or pain in the tip of your shoulder (where your shoulder ends and your arm begins). Symptoms of an ectopic pregnancy usually start between 4 and 12 weeks, so get advice right away, even if you have not had a positive pregnancy test yet
you have stomach pain that is severe or does not go away after you've rested for 30 to 60 minutes, or stomach pain with regular cramping or tightenings, lower back pain, or pain when you pee
your breathlessness comes on suddenly, you're out of breath when you're lying down, or you're breathless and also have chest pain or feel dizzy
you have pain or swelling in one leg, usually in the calf or thigh. This could be a blood clot (deep vein thrombosis, or DVT), which is more likely when you're pregnant
you have a high temperature (38C or above), or you feel hotter than usual or shivery. A high temperature can be a sign of an infection, so it's important to get it checked

If you cannot reach them, or you're not sure what to do, call NHS 111.

Speak to your GP or midwife if:

you're worried about your mental health, or stress, anxiety or low mood are affecting your day-to-day life. If you need urgent help for your mental health, call 111 and select the mental health option, or ask for an urgent GP appointment

Your week 10 checklist

This week:

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: NHS, Tommy's, Maternity Action. General information, not medical advice.

Sources & further reading

General information, not individual medical advice. Speak to your GP, midwife or health visitor about your baby’s needs.