Pregnancy Week 40

At 40 weeks pregnant, your baby is fully formed and ready for birth, although plenty of babies arrive after their due date. The brain, lungs and digestive system will continue maturing after birth too.

Your baby is still gaining small amounts of fat, receiving antibodies through the placenta, and practising movements, sucking and swallowing.

The skull bones are designed to overlap slightly during birth. This can make a newborn’s head look a little elongated at first, especially after a vaginal birth. It usually rounds out again over the first few days.

Your baby’s first breaths will be a major transition. Until birth, oxygen comes through the placenta and umbilical cord; afterwards, the lungs take over that work.

At 40 weeks pregnant, you may be having regular antenatal checks while waiting for labour to begin. Your midwife may check your blood pressure, urine, baby’s position, bump measurement and your baby’s movements.

You may be offered a membrane sweep around this stage, depending on local policy and your circumstances. A sweep aims to encourage labour by separating the membranes around the baby from the cervix during a vaginal examination.

If pregnancy continues beyond your due date, your midwife or doctor will talk to you about monitoring and induction options. In the UK, induction is often discussed if pregnancy continues beyond your due date, with local timing varying. It may be recommended earlier if there are concerns about you or your baby, or if your waters break and labour does not start. 

Call your maternity unit straight away if your waters break or you think they may be leaking, even if contractions have not started. Also call if contractions become regular according to your local advice, you have bleeding, severe pain, fever, baby movements reduce or feel different from your baby’s usual pattern, or you feel something is wrong. 

Week 40 can feel enormous. The due date may have been circled in your mind for months, so reaching it without a baby in your arms can feel strangely anticlimactic.

You may feel excited, impatient, tearful, calm, anxious, fed up, or deeply tired of being asked whether anything is happening. All of that is understandable.

Try to keep the focus on what you can control: resting, eating, staying hydrated, attending appointments, watching movements and knowing who to call. The rest is not a character test.

This week, focus on appointments, labour signs and what happens next if your baby stays put a little longer.

Useful checks this week:

If you are offered induction, ask what method is recommended, why, what the benefits and risks are, how long it may take, and what alternatives or monitoring options are available.