Royal baby: The different ways Kate Middleton can induce labour

Kate Middleton has apparently passed her due date for royal baby take two and well-wishers have been camped outside Queen Mary's Lindo Wing in anticipation of her arrival.

According to widespread media speculation, the Duchess of Cambridge was due on 25 April. Of course, no one other than the Royal inner circle really knows when Kate's due date is, but her pregnancy was announced on 8 September.

Being overdue is normal, with between five and 10% of pregnancies lasting longer than 42 weeks. Most babies are normally born between 37 and 41 weeks of pregnancy – with most arriving within a week either side of the due date.

If spontaneous labour has not occurred by 42 weeks, studies indicate there is a higher risk of stillbirth, so indication is offered to all overdue women. The induction process normally starts between 40 and 41 weeks.

Women are often offered a 'membrane sweep', which stimulates the cervix to release hormones that help to trigger labour naturally. However, most try out other options and set a date to have their labour formally induced with drugs.

With that in mind, here are some of the tricks believed to naturally induce labour. Please note there is no evidence to say any of these actually work.

Eating spicy food

This theory has been around for years. It is thought hot food like curry will stimulate your bowel, which also stimulates the nerve pathways to the uterus. Or it could just give you indigestion.

Have sex

This is thought to release oxytocin (the "bonding" hormone released during childbirth), which stimulates the uterus to get the body ready for labour. But the NHS website notes: "Having sex won't cause harm, but you should avoid having sex if your waters have broken as there is an increased risk of infection."

NB: under the same thinking, some people suggest stimulating your nipples.

Eat a pineapple

Or kiwi, mango or papaya. All of these fruits contain enzymes that can cause mild contractions because it is rich in bromelain, which is thought to help soften the cervix. However, these fruits only contain a small amount of bromelain – you would need to eat about seven pineapples for it to have any affect.

Walking

Taking a stroll is thought to encourage the baby's head to drop further down into the cervix and release oxytocin. Some say it also helps to shift the baby into a better position, which in turn will also mean labour is more likely to start on its own.

Acupuncture

This involves inserting very fine needles into specific points in the body to stimulate energy to act on an organ function or system. There is no evidence to suggest it works, but there is also no evidence to suggest it does any harm either.

Castor oil, raspberry leaf tea and herbal remedies

Do not do it. Castor oil can have side effects of nausea and diarrhoea. The thinking is that it acts as a powerful laxative that can also stimulate the uterus to start labour.

Raspberry leaf tea is not safe to start labour when overdue because it can start contractions that are so intense the baby becomes distressed.

Same with blue cohosh and black cohosh – the former of which has been linked with heart problems and strokes in babies at birth.

Medically induced

This involves going to hospital – contractions are started by inserting a tablet or gel into the vagine to soften the cervix. This can take a while – sometimes 24 to 48 hours. Induced labour is a bit more painful than labour that starts naturally and women are more likely to ask for an epidural. If this still does not work, you may be offered another induction or a caesarean section.