Pregnancy normally lasts about 40 weeks – that's around 280 days from the first day of your last period.
Most women go into labour a week either side of this date, but some women go overdue.
If your labour doesn't start by the time you're 40 weeks pregnant and this is your first pregnancy, your midwife will offer you a membrane sweep at your 40 and 41 weeks appointments.
If you've had a baby before, you'll be offered this just at your 41 weeks appointment.
A membrane sweep involves having a vaginal (internal) examination that stimulates the cervix (neck of your womb) to produce hormones that may trigger natural labour.
You don't have to have this – you can discuss it with your midwife.
Reasons for induction of labour
If your labour still doesn't start naturally after this, your midwife or doctor will suggest a date to have yourlabour induced.
If you don't want your labour to be induced and your pregnancy continues to 42 weeks or beyond, you and your baby will be monitored.
Monitoring you and your baby
Your midwife or doctor will check both you and your baby are healthy by offering you ultrasound scans and checking your baby's movement and heartbeat.
If there are any concerns about your baby, your doctor will suggest that labour is induced.
Induction is always planned in advance, so you'll be able to discuss the advantages and disadvantages with your doctor and midwife, and find out why they think your labour should be induced.
It's your choice whether to have your labour induced or not.
Over 42 weeks pregnant
Most women go into labour naturally by the time they're 42 weeks pregnant.
If your pregnancy lasts longer than 42 weeks and you decide not to have your labour induced, you should be offered increased monitoring to check your baby's wellbeing.
There's a higher risk ofstillbirth if you go over 42 weeks pregnant, although most babies remain healthy.
At the moment, there's no way to reliably predict which babies are at increased risk of stillbirth, so induction is offered to all women who don't go into labour by 42 weeks.
Having induction of labour after the date your baby is due doesn't increase the chance of having acaesarean section. There's actually some evidence it may slightly reduce the chance of having a caesarean section.