33weeks
pregnant

Medically reviewed by Clare Herbert, Senior midwife and team leader

Written by Chess Thomas

IN THIS ARTICLE

Highlights this week

Take it easy! Why you should avoid carrying heavy objects.

Baby development at 33 weeks

Your baby now weighs about 2.2kg (4.8lb), and measures over 44.1cm (17.4in) from head (crown) to heel (Hill 2019a).

Their brain develops rapidly throughout the third trimester (Konkel 2018). But once they’re born, and all their senses are stimulated, their brain growth will be super-charged (Konkel 2018).

Your baby's skin is becoming less wrinkled as they plump up in preparation for birth (Hill 2019a, Moore et al 2019). Their arms and legs are looking quite chubby now, thanks to the amount of white fat building underneath their skin (Hill 2019a, Moore et al 2019, Visembryo 2014).

Your baby's skull is soft and pliable, and the plates of bone that form it are not yet fused (Bailey 2014, Hill 2019b). If you have a vaginal birth, your baby's skull plates will slide over each other as they ease through the birth canal (Bailey 2014, Hill 2019b). You'll be able to see, or gently feel, the gaps (fontanelles) in your baby's skull when they’re born (NHS 2018a).

The fontanelles won't all close until your baby is about 18 months old (Bailey 2014, Hill 2019b). Throughout childhood, their skull plates remain flexibly joined to make space for their growing brain. The skull bones won't lock fully into place until adulthood (Hill 2019b).

If you're having a boy, his testicles are likely to have descended into his scrotum by now (Favorito and Sampaio 2014, Moore et al 2019b). However, sometimes, one or both testicles don't fully descend until after birth. This is especially common in babies who are born prematurely, or with a low birth weight (NHS 2018b, NICE 2014). If your baby is born with undescended testicles they should move down into his scrotum by about three months (NICE 2014).

baby with skin that is less red and see-through

Your baby's brain will triple in weight this trimester
The bones in your baby's skull can move and slightly overlap
Your baby's skin is smoothing out
The skin is less red and see-through

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Your baby weighs as much as a pineapple

length

44.1

head to toe

weight

2.2

kilograms

Pregnancy symptoms at 33 weeks

There’s no need to worry if your breasts are already leaking. In fact, they’ve been starting to make colostrum – your baby’s first milk – from about 14 weeks of pregnancy.

Not all women leak, but if you do, it can be awkward and uncomfortable. Invest in some breast pads – you can buy washable, reusable ones – and change them often to keep yourself and your clothes comfortable and dry.

If you’re having a healthy pregnancy with no complications, there’s no need to pump your colostrum and save it. Breastfeeding straight after the birth will give your baby all the nutrients they need. However, if you’re carrying twins or more, or you or your baby have had any complications, ask your midwife whether colostrum harvesting could be right for you.

baby in womb at 33 weeks pressing on bladder

With a baby pressing on your bladder, you probably have to pee more often

What you need to know at 33 weeks pregnant

Make life easier for yourself now. Stock up on essentials, everything from breast pads to nappies, before shopping becomes too much of a chore. Cook up extra portions when you’re making dinner to freeze ahead for the early weeks. You'll be glad you did when your baby's arrived.

Make sure you have all the important numbers in your phone – your midwife, doctor and the labour ward or birth centre. If you have pets and older children, arrange for someone to take care of them when the time comes. Then you'll be able to focus on just yourself and your baby.

If you're worrying about money, try not to spoil your maternity leave fretting. You may find that you don’t need as much baby gear as you thought, and it’s easy to pick up some great second-hand bargains. And speak to your midwife or children’s centre as they may be able to refer you to a local baby bank offering free clothes, nappies and other essentials like prams. You may also be entitled to benefits to help you manage.

With our first, we bought way too much stuff before baby arrived. It’s easy to get carried away buying fancy toys and gadgets that promise to make life easier. But at the end of the day, if you have a crib, a car seat, a pushchair or sling, some basic clothes and a good supply of muslins and nappies, you’re basically all set!

Mark

Your pregnancy to-do list at 33 weeks

Heartburn and indigestion can make life difficult in the third trimester. Get tips on dealing with them, plus delicious recipes, with our guide to eating well from 33 to 36 weeks.
If you're planning a hospital birth, discover clever ways to make the room feel more personal.
If you're buying baby equipment on a budget, read our tips for keeping down costs.
Watch our video to find out what to pack in your hospital bag.

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.

Bailey J. 2014. The fetus. In: Marshal J and Raynor M. ed. Myles textbook for midwives. 16th ed. Edinburgh: Churchill Livingstone, 91-100

Favorito LA, Sampaio FJ. 2014. Testicular migration chronology: do the right and the left testes migrate at the same time? Analysis of 164 human fetuses. BJU Int 113(4):650-3. onlinelibrary.wiley.comOpens a new window [Accessed November 2019]

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

Hill MA. 2019b. Musculoskeletal system - skull development. University of New South Wales Embryology. embryology.med.unsw.edu.auOpens a new window [Accessed November 2019]

Konkel L. 2018. The brain before birth: using fMRI to explore the secrets of fetal neurodevelopment. Environ Health Persp 126(11). ehp.niehs.nih.govOpens a new window [Accessed November 2019]

Moore KL, Persaud TVN, Torchia MG. 2019. Fetal period: ninth week to birth. Chapter 6 in The developing human: clinically oriented embryology. 11th ed. Elsevier

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

NHS. 2018b. Undescended testicles. NHS, Health A-Z. www.nhs.ukOpens a new window [Accessed November 2019]

NICE. 2014. Undescended testicles. National Institute for Health and Care Excellence, Clinical Knowledge Summaries. cks.nice.org.ukOpens a new window [Accessed November 2019]

Visembryo. 2014. 32 weeks post ovulation: fetus begins to develop immune system. www.visembryo.comOpens a new window [Accessed November 2019]