Week by week pregnancy guide: 31 weeks pregnant

You're now 31 weeks pregnant but what should you expect? Read week 31 of our week by week pregnancy guide to find out everything you need to know...

Tracking your pregnancy week by week (opens in new tab) can be helpful so that you know whether or not your symptoms are normal (or as normal as pregnancy symptoms get!).

At 31 weeks pregnant you'll start to feel more tired, so it's important you rest whenever you can.

There are a few other things to think about too, like how your baby is developing and what the potentially harmful things are to look out for. Here's everything you need to know...

31 weeks pregnant: Symptoms

Your uterus has grown to almost 500 times its original size. You'll be feeling more tired now, so get sleep when you can. You may feel a bit breathless as your baby is taking up so much space.

You may find yourself having a few Oops! moments. It's quite common to leak urine in the later stages of pregnancy - condition known as stress incontinence. It is caused by your baby exerting pressure on your pelvic floor - the hammock of muscles that supports your womb and bladder.

Your heart actually gets bigger during pregnancy as it copes with the demands of pumping all that extra blood around your body. Your heartbeat increases by 15 beats a minute and your heart pumps out seven litres of blood a minute instead of its normal five litres. What's more your heart also moves to the left and rotates slightly as it makes way for your expanding womb.

From any time onwards from now you make experience Braxton-Hicks contractions (opens in new tab). These will last around 25 seconds and will prepare you for what labour is like...

31 weeks pregnant: Fetal development

Your baby now measures about 40cm and weighs about 3lbs. They are becoming plumper and have laid down an impressive 2oz of fat. It may not sound much, but that figure represents 3.5% of their total body weight. By the time they are born, fat will represent 15% of their body weight (compared to 27% in an average-sized woman). From this point onwards they will carry on putting on weight, but the overall growth spurt will slow. You can no longer see the tracery of blood vessels beneath their skin, or the shadowy images that are their growing bones. Their lungs have yet to fully mature and their brain development is still on overdrive. Your baby can now tell light from shade and will be able to recognise your voice as well as any one you spend a lot of time with.

31 weeks pregnant: The changes you should make

First-time mums-to-be will have more routine antenatal appointments than mums who have already had one or more uncomplicated pregnancies. A check-up at week 31 is one of them. Your midwife will measure your blood pressure and test for protein in your urine. She will measure and plot your symphysis-fundal height to check how your baby is growing.

Most pregnancy niggles and discomforts are annoying but harmless. Occasionally, symptoms may be more serious. Always contact your midwife, GP or hospital at once if you experience any of the following:

• Bleeding from the vagina
• Severe swelling of hands, legs and/or face
• Severe or persistent headaches
• Blurred or disturbed vision - for example spots, flashes of light or dimness
• Sharp or prolonged pain in your abdomen
• Chills and/or fever
• Extreme itchiness, particularly on hands and feet
• Noticeable lack of fetal movement