40weeks
pregnant

Medically reviewed by Clare Herbert, Senior midwife and team leader

Written by Chess Thomas | 20 Aug 2021

IN THIS ARTICLE

Highlights this week

What you really need to buy for your baby before they arrive.

Baby development at 40 weeks

The average newborn measures about 51cm (20.1in) from head (crown) to heel, and weighs about 3.6kg (8lb) (Hill 2019a). Anywhere between 5.5lb and 8.8lb is considered a normal birth weight (Hill 2019b). Most of your baby’s fetal development is complete, but their hair may continue to get thicker and their nails may grow more, too (Medline Plus 2019a, Moore et al 2019).

All babies are born with two soft spots (fontanelles) at the top of their head, where the skull hasn't finished joining (NHS 2018, Visembryo 2014a). This allows your baby’s skull bones to shift over each other during vaginal birth, helping to ease their way along the narrow birth canal (Hill 2019c, Visembryo 2014a).

If your baby's born vaginally, their head may seem pointed or misshapen where it's been squeezed (NHS 2018, Visembryo 2014a). This is normal. It's also common, particularly after an assisted birth, for your baby to have a little swelling and bruising. Your baby's head will return to a more rounded shape in the days following birth (Visembryo 2014a), and the swelling and bruising will soon disappear (NHS 2018).

As a newborn, your baby has all the skills and reflexes that will help them to thrive, with your love and care (Visembryo 2014b). They’ll instinctively search for your nipple for a feed soon after birth (called "rooting"). And if you put your finger in their tiny hand they’ll grasp it tightly (Colson 2014, MedlinePlus 2019b, NHS 2018).

baby with head with soft spots called fontanels

Your baby at 40 weeks

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Your baby is around the size of a small pumpkin

length

head to toe

weight

3.6

kilograms

Pregnancy symptoms at 40 weeks plus

Sleep at this stage may not come easily to you. Do keep trying to fall asleep on your side though. Although stillbirth is rare, this will reduce the risk. See our tips for getting a better night’s sleep in these last days of your pregnancy.

You could catch up on your shut-eye by taking a nap during the day (still sleeping on your side). Or just rest and play some soothing music. Dozing will do you good and help to build up your energy stores for labour. In fact, getting plenty of rest in the days before labour starts is actually linked to a quicker birth and a lower risk of needing a c-section.

Try not to worry if you never seem to get a good night's sleep these days, though. You may feel a little gritty-eyed during the day, but it won’t do you or your baby any harm.

Your body at 40 weeks

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What you need to know at 40 weeks pregnant and beyond

After months of anticipation, your due date goes by, and... you're still pregnant. It's a frustrating, but common, situation. If you're running out of patience, it may help to remind yourself that your due date is only an estimate. At 40 weeks, your doctor or midwife won't consider you overdue for another week yet.

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A few mums-to-be have what is called a prolonged pregnancy, which lasts longer than 42 weeks. Your midwife will keep an eye on you during these final days. You should have an antenatal appointment each week. If your pregnancy has been straightforward, your midwife should offer you an induction after 41 weeks.

Are your friends and family ringing or messaging you every day to find out how things are going? If it's frustrating you, explain that you'll call when your baby is definitely on their way and not before!

If time's dragging and you have the energy, fit in a few last-minute treats. It won't be so easy after your baby's born. Enjoy a meal out with friends, curl up with a box set, or just enjoy some quiet time with your partner.

If you think your labour has started, but you're not sure, phone your local maternity unit and ask for advice. Don't hesitate to give them a call if you're worried. Remind yourself of the signs of labour.

When my first baby was born, my mum announced it on Facebook before we got the chance to tell people. This time, we’ve had a discreet word with everyone asking them not to do this, so hopefully we’ll get to spread the news ourselves.

Sarah

Your pregnancy to-do list at 40 weeks plus

Wondering if there are any foods you can eat to help get labour going? Check out our guide to eating well once you’re past your due date.
Use this time to double-check your birth plan. Compare it with our sample birth plans in case you've missed something or want to rethink some points as the big day approaches.
From day one your baby's navel and umbilical cord will need looking after. Find out how to keep their umbilical stump clean.
While you’re waiting for your baby to make an appearance, watch our video to remind yourself of the best positions for labour.

Check out the BabyCentre podcast!

The Parent Pod is BabyCentre’s brilliantly entertaining and informative podcast series. Join hosts Claire and Lucy as they walk your exciting journey with you each week from early pregnancy until your baby is 12 weeks old. Subscribe now on the usual channels. Learn more

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Sources

BabyCentre's editorial team is committed to providing the most helpful and trustworthy pregnancy and parenting information in the world. When creating and updating content, we rely on credible sources: respected health organisations, professional groups of doctors and other experts, and published studies in peer-reviewed journals. We believe you should always know the source of the information you're seeing. Learn more about our editorial and medical review policies.

Colson S. 2014. Does the mother's posture have a protective role to play during skin-to-skin contact? Clinical Lactation 5(2):41-50

Hill MA. 2019a. Fetal development. University of New South Wales Embryology. embryology.med.unsw.ed.auOpens a new window [Accessed December 2019]

Hill MA. 2019b. Birth weight. University of New South Wales Embryology. embryology.med.unsw.ed.auOpens a new window [Accessed December 2019]

Hill MA. 2019c. Musculoskeletal system: skull development. University of New South Wales Embryology. embryology.med.unsw.ed.auOpens a new window [Accessed December 2019]

MedlinePlus. 2019a. Fetal development. Medline Plus. US National Library of Medicine. medlineplus.govOpens a new window [Accessed December 2019]

MedlinePlus. 2019b. Infant reflexes. Medline Plus. US National Library of Medicine. medlineplus.govOpens a new window [Accessed December 2019]

Moore KL, Persaud TVN, Torchia MG. 2019b. Integumentary system. Chapter 19 in The developing human: clinically oriented embryology. 11th ed. Elsevier

NHS. 2018. Getting to know your newborn. NHS, Health A-Z, Pregnancy and baby. www.nhs.ukOpens a new window [Accessed December 2019]

Visembryo. 2014a. 38 weeks post ovulation: abdomen is large and round as fetal liver is producing blood cells. www.visembryo.comOpens a new window [Accessed December 2019]

Visembryo. 2014b. 40 weeks post ovulation: fetus now considered full term. www.visembryo.comOpens a new window [Accessed December 2019]