Many mums hope for a birth on or around their baby’s due date. Find out what happens if your baby is late or overdue and about the induction of labour
If you’ve been focusing on your due date throughout your pregnancy, it’s understandable that you might feel disappointed or worried if you go past that date with no sign of baby. But did you know that only about 5% of babies are actually born on their ‘due’ date?
Pregnancy is measured from the date of your last period, and conception could have occurred at different times in the weeks after that. Even if you’re sure of the date of conception, the length of pregnancy can still vary by about five weeks.
When is a baby overdue or ‘late’?
Around 80% of babies are born between 38 and 42 weeks of pregnancy. This is often called ‘at term’. Babies born after 42 weeks are described as ‘post-term’ while those born before 37 completed weeks are ‘preterm’ or 'premature'.
Why are some babies overdue or ‘late’?
It’s not known exactly what starts off labour or why some babies are born later than others. It’s possible that your baby’s position may affect the start of labour. If your midwife tells you the baby is ‘breech’ (with head up and feet or bottom down) or is ‘occiput posterior’ (head down, but facing your front) you may want to consider trying positions and movements that help your baby move into the best position for birth.
If you go past your due date, it can also be helpful to remember that your baby may not be quite ready to be born. The ‘due’ date given by your midwife or GP is only to indicate a likely time for the birth, not the best time for your baby to be born. Hormonal changes during the last few weeks of pregnancy help to prepare babies’ heart, lungs, skin and other organs for the environment outside the womb; babies born early can need extra help with breathing or feeding.
There are different ways that women have used to try and bring on labour themselves, such as having sex, acupuncture, reflexology or aromatherapy, but there’s no evidence that any of these work.
One thing we do know is that your body produces labour hormones more readily if you’re relaxed; one way of helping things along might be to try some relaxation exercises, or doing something that helps you relax.
What is a membrane sweep?
If your labour hasn’t started by 41 weeks, your midwife will probably offer you a 'membrane sweep'. This involves having a vaginal examination, when she will insert a finger gently into your cervix and move it between the top of the cervix and the bag of waters. This may stimulate the cervix to produce the hormones, called prostaglandins, which trigger spontaneous labour.
This has been shown to increase the likelihood of labour starting in the next few days, and to decrease the need for induction, but it isn’t always effective. Some women have reported bleeding and discomfort after a membrane sweep. You don't have to have this, but it is worth considering if you wish to avoid medical induction.
When is labour induced?
Induction (starting labour off artificially) is offered to all women who don't go into labour naturally by 42 weeks, as there is a higher risk of stillbirth or problems for the baby if you go over 42 weeks pregnant.
If you don't want to be induced, and your pregnancy continues to 42 weeks or beyond, you and your baby will be monitored. Your midwife will check that both you and your baby are healthy by offering ultrasound scans and checking your baby's heartbeat. If your midwife is concerned about the baby, they will suggest that labour is induced.
You may also be offered an induction if your waters have broken or if you or your baby have a health problem.
What happens in an induction of labour?
Induction can be carried out in at least two ways. Usually the first to be tried is a prostaglandin pessary. This is a soluble device, containing the hormone prostaglandin, inserted in the vagina, which will help soften the cervix and allow labour to progress as it would naturally.
Some women choose to go home while they wait for the pessary to work but contact your midwife or obstetrician if your contractions begin or you have had no contractions after six hours.
If you've had no contractions after six hours, you may be offered another tablet or gel.
If you have a controlled-release pessary inserted into your vagina, it can take 24 hours to work. If you aren't having contractions after 24 hours, you may be offered another dose.
The other commonly used method is a syntocinon drip. Syntocinon contains an artificial form of oxtyocin, the hormone which helps your womb contract. A tube is put into your arm, using a needle, and it gradually releases the oxytocin.
Continuous electronic monitoring of the baby's heartbeat is usual to ensure that the drug used to stimulate the contractions is not putting the baby under stress. Syntocinon is often used alongside the manual ‘breaking of the waters’ (when the midwife intentionally punctures the amniotic sac to promote the start of labour), with the drip in place ready for when the waters have been broken.
How does induction affect labour?
Induced labour is usually more painful than labour that starts on its own, and women who are induced are more likely to ask for an epidural. You are also likely to be less mobile and you won’t be able to use a birthing pool.
Your pain relief options are not restricted by being induced. You should have access to all the pain relief options usually available in the maternity unit.
Women who are induced are more likely to have an assisted delivery, where forceps or ventouse suction are used to help the baby out. However, there is some evidence that women who are induced may be less likely to have a caesarean section.
NICE guidance makes it clear that your decision about whether or not to have an induction should be respected, and that the exact timing should take into account your preferences and local circumstances. Some women may take up the offer of induction because they're feeling really heavy and uncomfortable; while others may feel it's not right for them and are willing to wait a few more days to see if labour starts spontaneously.
What if labour induction doesn't work?
Induction isn't always successful, and labour may not start. Your obstetrician and midwife will assess your condition and your baby's wellbeing, and you may be offered another induction or a caesarean section. Your midwife and doctor will discuss all your options with you.
While it can feel frustrating to go past your due date; remember that your ‘due date’ is an estimated date and you can always talk to your midwife about your options.
NCT's helpline offers practical and emotional support in all areas of pregnancy and early parenthood: 0300 330 0700. We also offer antenatal courses which are a great way to find out more about labour and life with a new baby.
Find out more about NICE guidance on the induction of labour