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!

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 27 – your 2nd trimester

Pregnancy is divided into 3 chunks, called trimesters. Next week, you will start the 3rd and final trimester.

What's happening in my body?

You're probably putting on a few pounds now and you may be feeling bloated and constipated. This is partly because your stomach is being squeezed by your growing baby, and partly due to the pregnancy hormone, progesterone.

It might help to drink lots of water, choose high fibre options (such as brown bread, rather than white) and eat lots of fresh fruit and veg.

Read more tips to deal with bloating on week 10's page.

The best sleeping positions during pregnancy

Should you sleep on your back or side? The NHS guidance says that sleeping on either side is better than sleeping on your back. That's because after week 28, research suggests that sleeping on your back can double the risk of stillbirth. It's also more likely to give you backache, constipation and piles.

Here are some tips for a safe and sound night's sleep:

  • support your baby bump with a pillow
  • keep your knees and legs bent
  • put another pillow between your legs
  • if you roll onto your back, don't worry, just roll back onto your side again

Are you fit to fly?

This is probably the last week you can fly anywhere without a “fitness to fly note”.

If you need to fly after this you will need a note from your midwife or doctor to confirm that your pregnancy is uncomplicated. Check the cut off dates with your airline.

Find out more about travel during pregnancy.

2nd trimester pregnancy symptoms (at 27 weeks)

You may be feeling tired now, so nap when you can. You might be snoring more. Snoring is very common in pregnancy as your nasal passages are more likely to become swollen and blocked.

Your signs of pregnancy could also include:

You may also experience symptoms from earlier weeks, such as:

Read Tommy's guide to common pregnancy symptoms.

What does my baby look like?

Your baby, or foetus, is around 36.6cm long from head to heel, and weighs about 875g. That's approximately the size of a big leek, and the weight of a head of cauliflower.

Your baby's lungs are now capable of breathing. Your baby is also getting plumper by the day. A few weeks ago, your baby looked a bit like a wrinkled prune. Now the folds of skin are being filled out by fat, and all their organs are maturing, as your baby prepares for life outside the uterus (womb).

Action stations

Do you know where you would like to give birth? This is a great time to start thinking about it. If you're concerned about how coronavirus might affect your birth plan, visit the Royal College of Obstetricians and Gynaecologists for the most up-to-date advice.

This week you could also...

You have maternity rights. You can ask for a risk assessment of your work place to ensure that you're working in a safe environment. You should not be lifting heavy things and you may need extra breaks and somewhere to sit. You can also attend antenatal appointments during paid work time.

It's a good time to tone up your pelvic floor muscles. Gentle exercises can help to prevent leakage when you laugh, sneeze or cough. Get the muscles going by pretending that you're having a wee and then stopping midflow. Visit Tommy's for more ideas about pelvic floor exercises.

Ask your midwife or doctor about online antenatal classes – they may be able to recommend one. Tommy's has lots of useful information on antenatal classes and preparing you for birth.

Even if you've had children before, they're still worth going to as you can meet other parents-to-be. The NCT offers online antenatal classes with small groups of people that live locally to you.

Do your best to stop smoking, give up alcohol and go easy on the tea, coffee and anything else with caffeine. Ask your midwife or GP for support if you need it.

To keep bones and muscles healthy, we need vitamin D. From late March/early April to the end of September, most people make enough vitamin D from sunlight on their skin. However, between October and early March, you should consider taking a daily vitamin D supplement because we cannot make enough from sunlight.

Some people should take a vitamin D supplement all year round, find out if this applies to you on the NHS website. You just need 10 micrograms (it's the same for grown-ups and kids). Check if you're entitled to free vitamins.

It's recommended that you do 150 minutes of exercise a week while pregnant. You could start off with just 10 minutes of daily exercise - perhaps take a brisk walk outside. Check out Sport England's #StayInWorkOut online exercises (scroll to the pregnancy section). Listen to your body and do what feels right for you.

There's no need to eat for 2. You don't need any extra calories until the 3rd trimester, which starts in week 28. Try and eat healthily with plenty of fresh fruit and veg, and avoid processed, fatty and salty foods. You may be able to get free milk, fruit and veg through the Healthy Start scheme.

How are you today? If you're feeling anxious or low, then talk to your doctor or midwife who can point you in the right direction to get all the support that you need. You could also discuss your worries with your partner, friends and family.

You may be worried about your relationship, or money, or having somewhere permanent to live. Don't keep it to yourself. It's important that you ask for help if you need it.

Having another baby is probably the last thing on your mind. However now is a good time to start planning what type of contraception you would like to use after your baby is born.

Getting pregnant again could happen sooner than you realise and too short a gap between babies is known to cause problems. Talk to your GP or midwife to help you decide.

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
  • To find out about about COVID-19 and pregnancy, childbirth and breastfeeding, have a look at advice on the:

  • NHS website
  • Breastfeeding Network
  • World Health Organization
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