22 weeks pregnant: baby's development, stretch marks and preventing infections

Your baby now weighs around one pound. From around now, they start to weigh more than the placenta. They’re about the size of a bag of sugar.

Your baby’s development this week

Your baby is getting into a pattern of sleeping and waking, which may not be the same as yours. When you're in bed at night trying to sleep, your baby may be wide awake and moving about.

Your baby’s lungs are not yet ready for life outside the womb but they’re developing fast. Even though they can’t breathe in the womb, your baby is practising their breathing movements for life outside.

They get all their oxygen from your blood through the placenta until they take their first breath after they're born.
Smoking decreases the amount of oxygen in the placenta, so it’s very important to stop if you’re still smoking. It's not too late, every day without smoke will help your baby's health.

Get help to stop smoking.

Your pregnancy symptoms in week 22

Stretch marks

During pregnancy your hormones can soften the fibres of your skin, making it more prone to stretch marks. These are streak-like marks that appear on your bump, or possibly boobs and thighs. They aren’t harmful and don’t cause any medical problems. 

Stretch marks in pregnancy are common, completely natural and will fade after your baby is born.

Swollen feet and hands

If rings on your fingers or your shoes feel a bit tight, this is maybe because of more fluid in your body (known as oedema).

This is normal during pregnancy. But get medical advice from your midwife, GP or the hospital straight away if you have any of the following symptoms:

  • a severe headache
  • vision problems, such as blurring or flashing
  • pain just below the ribs
  • vomiting
  • sudden swelling of the face, hands or feet.

These symptoms can be signs of pre-eclampsia.

What to do in week 22

Don't forget your pelvic floor

Make sure you give your pelvic floor muscles a workout as part of your daily routine. Try doing them when you brush your teeth or put the kettle on. Toning up your pelvic floor muscles an help reduce the risk of stress incontinence – small leakages of wee when you cough, laugh or sneeze.

“I exercised throughout both my pregnancies, right up until my due date. I was a lot more tired in the second pregnancy, because I was running around after my daughter, but I always did something active because it made me feel better.”

The whooping cough vaccine

Speak to your midwife or GP if you haven’t been offered the whooping cough vaccine yet. Getting vaccinated while you’re pregnant can protect your baby from developing whooping cough in the first few weeks of life. 

It’s understandable to feel nervous about having a vaccination in pregnancy. But there is no evidence that the whooping cough vaccine is unsafe for you or your unborn baby.

The Covid-19 vaccine

We're here to support you with the latest information about pregnancy and coronavirus, which is based on official guidance from the Royal College of Obstetricians and Gynaecologists (RCOG).

Try to avoid infections

Getting an infection in pregnancy is not likely to harm your baby. But it is important to do what you can to avoid them.

Simple ways to avoid infections in pregnancy include:

  • washing your hands regularly with soap and water
  • trying to avoid people who are unwell
  • avoiding changing or touching dirty cat litter or contaminated soil
  • making sure all your meals are properly cooked, especially meat
  • avoiding unpasteurised milk and foods made with it
  • avoiding sharing food, cutlery, drinking glasses or dummies with young children.

Contact your GP, doctor or midwife straight away if you have a high temperature or any symptoms of an infection.

1. Regan, Lesley (2019) Your pregnancy week by week, Penguin Random House, London

2. NHS. Stretch marks in pregnancy. https://www.nhs.uk/pregnancy/related-conditions/common-symptoms/stretch-marks// (Page last reviewed: 27 March 2020. Next review due: 27 March 2023) Accessed: September 2021

3. NHS. Pre-eclampsia. Pre-eclampsia - NHS (www.nhs.uk) (Page last reviewed: 28 September 2021 Next review due: 28 September 2024)

4. NHS. Whooping cough vaccination in pregnancy. https://www.nhs.uk/pregnancy/keeping-well/whooping-cough-vaccination/ (Page last reviewed: 17 October 2019. Next review due: 17 October 2022) Accessed: September 2021

Review dates
Reviewed: 11 July 2022
Next review: 11 July 2025