My premature baby’s development in the womb – week 23

If you have been told you are at risk of a premature birth, you may be feeling anxious. Here’s some information about your baby’s development this week.

This information is for women who have been told that they are at risk of a premature birth

If you are not at risk of having a premature baby, we have information for you in our pregnancy calendar -our week-by-week guide to the stages of pregnancy

Your baby's development this week

Your baby’s skin isn’t completely translucent anymore but is still shiny and thin.  Your baby also has a very fine downy covering of hair on their body which is called lanugo.

The surface of the skin is covered in a white sticky substance called vernix. When babies are born prematurely, they are often still covered in vernix, which is left to absorb naturally. It's a natural moisturiser that also protects against infection in the first few days.  

Your pregnancy symptoms

Back pain

Back ache or pain is very common in pregnancy. During pregnancy, your ligaments loosen up and stretch to get your body ready for labour. This puts strain on your joints, which can cause back pain. 

Pregnancy also affects your posture (the way you hold your body up while standing or sitting). When you’re pregnant, the natural curve in your spine increases because it’s trying to cope with the extra weight of your baby bump. This can cause pain.  

If you have mild back pain, it is generally better to stay active and exercise as best you can.  Paracetamol may also help.  If you have back pain you can speak to your midwife who may recommend exercises or a support belt, and/or refer you to a physiotherapist. 

Back pain may also be a sign of a urinary tract infection. Pregnant women can be more likely to get urinary tract infections because of the changes their body goes through. UTI infections can cause premature birth if they are not treated.  Your midwife will test your urine at every antenatal appointment. You must also contact your midwife at any time if you have any symptoms such as back pain, a painful or burning sensation when you pass urine or if you feel generally ill. 

It is not an emergency if you get a UTI in pregnancy, but it should be treated as soon as possible. Find out more about symptoms and treatment for urinary tract infections. 

Find out more about back pain in pregnancy

If you have back pain that's not usual for you, contact your midwife or hospital maternity unit. This may be a sign of premature labour.  

Other symptoms

If you are at risk of giving birth early, it’s important to take care of yourself. There are also some things you can do to try and reduce the risk of giving birth early.

Tell your midwife or doctor if you have any symptoms that you are worried about. Do not worry if you've talked about it before and don't be concerned about whether you're wasting anyone's time. This is your pregnancy and it's important to trust your own instincts if you feel something isn't right.

You can also call the Tommy’s midwives on 0800 014 7800 (Monday to Friday, 9am to 5pm), or email us at [email protected].

Symptoms of early labour

Call your midwife or hospital maternity unit straight away if you think you are in early labour. It may be a false alarm, but it’s best to get checked out. Find out more about the symptoms of early labour

Your mental health

If you have been told that you are at increased risk of giving birth early, it’s important to try and reduce stress and take care of your emotional health. Find out more about coping with the idea of a premature birth.

What may happen if your baby is born this week

This information may be difficult to read. If you have any questions about your pregnancy or risk of premature birth please talk to your doctor or midwife.

You can also call the Tommy’s midwives on 0800 014 7800 (Monday to Friday, 9am to 5pm), or email us at [email protected].

Babies born before 28 weeks are described as being extremely preterm. Research shows that for babies born before 27 weeks of gestation it is best, whenever possible, to be born in a specialist maternity unit with a specialist Neonatal Intensive Care Unit. If you are in labour and aren’t at a hospital with these facilities, you may be taken to one as soon as possible. This is known as in utero transfer

Sadly, most babies born at this gestation will not survive labour and birth. At 23 weeks, this is known as a late miscarriage.

Approximately 6 in 10 babies don’t survive if they are born now, even if they are born alive and receive treatment to try and save their life. Of those who do survive, 1 in 4 babies born at this time will have a severe disability, such as cerebral palsy.

Up to 1 in 4 of children without a severe disability may have a milder disability, such as learning difficulties, behavioural problems or mild cerebral palsy. 

When talking about babies who have been born extremely prematurely, the term severe disability can include: 

  • not being able to walk or even get around independently (this includes conditions such as severe cerebral palsy) 
  • being unable to talk, or see or hear properly 
  • difficulties with swallowing or feeding safely 
  • having multiple health problems with frequent visits to hospital
  • needing to attend separate school for children with special educational needs 
  • being unable to care for themselves or live independently as they grow up. 

What does this mean for your premature baby? 

Every baby is different and it is important to talk with your doctors and midwife. They will give you specific information about your own and your baby’s condition. The chances of your baby’s survival and long-term health will depend on several other factors, not just the week they were born. How much your baby weighs, their gender, and how well you and your baby are when you give birth will all have an impact.

Your doctors will talk to you about what your options are and help you make decisions about what’s best for you and your baby.

You and your healthcare team may decide that it will be best to provide palliative care to your baby, either because there is an extremely high risk that your baby will not survive or they are likely to suffer from life-long disability, even with the very best treatment. Palliative care means providing treatments that will make them as comfortable as possible until they pass away. 

You and your healthcare team may decide that starting neonatal intensive care would be best for your baby. Babies born at this time have the highest risk of breathing problems because their lungs have not matured and will need help to breathe.

The medical team will usually put a breathing tube passed through their mouth or nose and into their lungs (known as intubation), which is connected to a machine called a ventilator. This machine does most or all of the breathing for the baby. Your baby will also be given some medicine into their lungs (surfactant) to help with their breathing. Find out more about breathing support for premature babies

Babies born now will not be able to feed independently and are at risk of complications such as hypothermia (when their temperature is low), heart and blood flow problems, low blood pressure, high or low blood sugar and infections. The medical team will monitor all these things and provide treatment when necessary.

British Association of Perinatal Medicine. (2019) Perinatal Management of Extreme Preterm Birth before 27 weeks of gestation British Association of Perinatal Medicine.

NHS. Getting to know your newborn. (Page last reviewed: 20 February 2018. Next review due: 20 February 

Sue Macdonald and Gail Johnson Mayes’ Midwifery (Edinburgh: Baillir̈e Tindall Elsevier, 2017) p.531
Clinical Knowledge Summaries (2020) Back pain – low (without radiculopathy)

Clinical Knowledge Summaries (2021) Antenatal care – uncomplicated pregnancy.
Kalinderi K, et al. Urinary tract infection during pregnancy: current concepts on a common multifaceted problem. Journal of Obstetrics and Gynaecology. 2018;38(4):448-453. doi:10.1080/01443615.2017.1370579

NHS. Urinary tract infections. (page last reviewed 18 November 2020 Next review due 18 November 2023)

NHS. Premature labour and birth. (page last reviewed: 9 December 2020 Next review due: 9 December 2023)
NICE (2019). Specialist neonatal respiratory care for babies born preterm. National Institute for health and care excellence.

NHS Thames Valley & Wessex Operational Delivery Networks (2019) Too small too soon. Information for parents of babies born early around 22 to 24 weeks.

Review dates
Reviewed: 23 August 2021
Next review: 23 August 2024