40 weeks pregnant: advice, symptoms and baby development

woman with 40 week bump

by Deborah Cicurel |

At forty weeks pregnant, you’re getting so close to the end of the pregnancy journey and meeting your very own little baby! Find out what’s happening to your baby and to your body and any symptoms you might experience now you’ve reached the 40th week of pregnancy.

How big is my baby at 40 weeks pregnant?

Your baby is fully grown and ready to be born now and is the size of a watermelon. They will weigh between six and nine pounds, and will usually measure between 19 and 22 inches, though they could be bigger or smaller once you finally get to meet them.

40 week old pregnant

What is my baby doing at 40 weeks pregnant?

It’s the official end of your pregnancy, but your baby may not realise it yet. Around 30 per cent of pregnancies last longer than 40 weeks. Hang in there - it’s nearly time to meet your little one!

While they are still living inside your tummy, you’re still providing the antibodies they need to fight infections for the first few months of their life, via the umbilical cord. If you decide to breastfeed, they will get more antibodies to boost their immune system and will get even more from the colostrum that you’ll feed them for the first few days of their life.

Once they are born, you’ll no doubt first check to see the sex, and whether your little one is a boy or a girl! Once that exciting revelation is over, there is so much to admire. Their tiny hands and feet, and of course, their little eyes.

Babies at birth can only focus about an inch away, so you may look a little blurry at first, but make sure you talk lots to your little one, as they will recognise both your and your partner’s voice.

When your baby comes out, you might notice that they are still curled up in the foetal position. After being in one position for so long, it’ll take a while for your little one to realise they have plenty of room to spread out - plus, it’s comforting for them to be in the foetal pose, as it’s the only position they have ever known. Try swaddling them to remind them of the cosy position they adopted in your uterus.

What is my body doing at 40 weeks pregnant?

The weight of your baby on your cervix will put pressure on the tissues, which helps to thin it (known as ripening or effacing) and open it up ready for birth. If your midwife were to do an internal examination now, they may discover you’re already a couple of centimetres dilated, even if you haven’t had any contractions.

Your doctor or midwife will also check plenty of other things: they'll do an ultrasound to look at your baby’s breathing movements, muscle tone and overall movement as well as the amount of amniotic fluid that surrounds them, carry out a foetal heart monitoring test and they'll also check your cervix to look at its position, how soft it is, how dilated it is and how effaced it is.

If you don’t go into labour soon, you’ll likely be induced next week or the week after.

Common symptoms to look out for

Water breaking: The embarrassing moment when your water breaks in public is mostly the stuff of movies, as most women experience their water breaking while they are already in the hospital and in labour. While less than 15 per cent of women experience their water breaking before labour, if you do experience this, whether it’s a gush or a small leak, call your doctor straight away, as it means labour will either begin within 24 hours, or your doctor will start it for you. The water breaking means that the amniotic sac that has been surrounding your baby for the last nine months has ruptured. The amniotic fluid is colourless and odourless, so if your water breaks and you notice any green and brown colours, call your doctor right away, as it could mean that your baby has had a bowel movement in utero.

Insomnia:As the big day gets closer than ever, it’s getting harder and harder to get 40 winks. Avoid caffeine and invest in a pregnancy pillow to make nodding off a little bit easier.

Leg cramps: Carrying around all that extra weight is bound to impact your legs, and it may come in the form of unpleasant and painful leg spasms. Flexing your ankles can help.

What to do this week

Although you’ve reached 40 weeks pregnant, there’s no guarantee that your baby will want to come out just yet. Very few babies arrive on their due date and in reality, they could turn up anytime between weeks 37 and 42.

However, if you just can’t wait to meet them, there are a few things you can do to speed the process up. Here are just some of them…

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Nipple stimulation
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Nipple stimulation

This can release oxytocin, which causes the body to have contractions. Gently rub or roll your nipples, or get your other half to. Alternatively, if it’s not too painful, use a breast pump. However, because this activity can overstimulate your uterus, it’s best to do this when you’re being monitored, rather than trying it at home.

Take me back to week 39

Take me to week 41

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