size of baby at 13 weeks?

Week-by-week guide to pregnancy
group of pregnant women
When you're pregnant, you have lots of questions. Our week-by-week pregnancy guide is packed with lots of useful information. From what's happening inside your body, to how your baby is developing, and tips and advice on having a healthy pregnancy – this is your one-stop pregnancy guide!

1st trimester
2nd trimester
3rd trimester

2nd trimester

Our week-by-week pregnancy guide is full of essential information. From staying fit in pregnancy to advice on your maternity rights, you'll find it all here.

Week 13
Week 14
Week 15
Week 16
Week 17
Week 18
Week 19
Week 20
Week 21
Week 22
Week 23
Week 24
Week 25
Week 26
Week 27

Week 13 – your 2nd trimester

You are now a 3rd of the way through your pregnancy and you're hopefully through the worst of your symptoms.
What's happening in my body?

A small baby bump may now be visible as your uterus (womb) grows upwards and outwards. If you've been feeling the urge to pee more often, that should stop as the womb moves away from your bladder.

Meanwhile, there's a lot more blood pumping around your pelvic area and some women find that it increases their sex drive. It could also make you feel more thirsty, so drink lots of fluids.

Sex during pregnancy is perfectly safe, unless your midwife or doctor has advised you otherwise.
Infection alert

There are ways you can protect yourself and the baby from many harmful viruses and bacteria:

Try to avoid contact with anyone who has chickenpox or rubella – talk to your doctor or midwife straight away if you think you could be infected.
If you have a cat, get someone else to empty the cat litter tray, as the faeces could contain a bug called toxoplasma gondii. This can cause an infection called toxoplasmosis that could damage your unborn baby.
You can also get toxoplasmosis from certain foods. Foods to avoid during pregnancy include undercooked meats, cured meats like salami, and unpasteurised goats' milk and cheese.
Seek advice before travelling to any area affected by the Zika virus, as the virus can cause birth defects.

Read more about infections in pregnancy on the NHS website.
Coronavirus (COVID-19)

You and your family should follow the government and NHS guidance on coronavirus (COVID-19):

read government guidance on how to stay safe from COVID-19
get NHS advice about COVID-19
use the NHS COVID-19 app for England and Wales - it's the fastest way of knowing when you've been exposed to COVID-19

Teeth troubles

Swollen, painful and bleeding gums are common during pregnancy. Read about keeping teeth and gums healthy in pregnancy on the NHS website.

You are entitled to free NHS dental care during pregnancy and for a year after your baby is born. Ask your doctor or midwife for a maternity exemption certificate.

You already know the basics – clean your teeth twice a day, avoid sugary snacks and drinks, and don't smoke as it can make gum disease worse. But did you also know that:

a soft toothbrush is best for sensitive gums
you should brush in gentle circles, up and down
if you're sick, protect your teeth by rinsing your mouth out with water, to flush away harmful acid in your vomit
you should stick to alcohol-free mouthwashes to reduce plaque

2nd trimester pregnancy symptoms (at 13 weeks)

Your signs of pregnancy could include:

swollen and bleeding gums
pains on the side of your belly caused by your expanding womb (known as "round ligament pains")
headaches
nosebleeds
bloating (read ways to cope with bloating on week 10's page)
constipation (read about how to treat constipation on week 16's page)
indigestion and heartburn (read ways to cope with indigestion and heartburn on week 25's page)
sore breasts
leg cramps
feeling hot
dizziness
swollen hands and feet
urine infections
vaginal infection (read about how to treat vaginal infections on week 15's page)
darkened skin on your face or brown patches – this is known as chloasma or the "mask of pregnancy"
greasier, spotty skin
thicker and shinier hair

You may also still experience symptoms from earlier weeks, including:

morning sickness
unusual pregnancy cravings
heightened sense of smell
mood swings
white milky pregnancy discharge from your vagina
light spotting (seek medical advice for any bleeding)

Read Tommy's guide to common pregnancy symptoms.
What does my baby look like?

Your baby, or foetus, is around 7.4cm long, which is about the size of a peach. The weight is about 25g, which is as heavy as a toothbrush with toothpaste on it.

Your baby's ovaries or testes are fully developed inside and final tweaks are being made on the outside. The baby is moving around. At first the movements are very jerky and random but then they start to look more deliberate.

You may not feel any movement until around week 17. Some babies suck their thumb in the womb. This actually serves a purpose as it helps to develop their sucking reflex. They'll need this when it comes to feeding.

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