There are many ways to bring on labour. Consuming something: eating or drinking, are very popular methods not least because they are often quite accessible to pregnant ladies and don’t cost much, or may not require specialist information.
They are not necessarily effective or their efficacy may not be quite what you expect. Proceed with caution!
DISCLAIMER: Birthzang is a trained and FEDANT accredited antenatal educator but I am in no way recommending any of these foods to bring on labour. I list them here purely for information purposes and any activity undertaken by desperate and overdue readers is taken entirely at their own risk!
This is probably one of the really famous methods to bring on labour. Pineapple, and other tropical friuts such as kiwi and papaya contains the enzyme bromelain, particularly in the stems, which is thought to help stimulate prostaglandins that help ripen the cervix. It must be eaten fresh as canning or juicing destroys the bromelain.
Probable efficacy: poor. The bad news is that it has very tiny quantities so you’d probably have to eat at least 7 pineapples , if not more, to have any effect on your bromelain levels so unless you have a mouth of steel and are not prone to indigestion then it ain’t gonna do much. The efficacy really is going to be in giving you diarrhoea which can cause contractions – not the nicest way to induce labour though.
HOT AND SPICY FOOD
Curry eating, like pineapple, is quite a famous method. The hotter and spicier the better, providing your heartburn can take it. The theory is actually the same as pineapple and other methods by using the chilli to give you a mild tummy upset. If your bowels are going a bit mad then the idea is it will nudge the uterus – sitting right next door – into action. 
Probable efficacy: medium. Tastes nice, not going to hurt (unless you fancy a double ring-of-fire). Works just as well with Mexican, Thai – basically the key ingredient is chilli.
We are talking here about natural liquorice not the sweetie version. This is an interesting one. Liquorice contains something called glycyrrhizin, which can affect hormone levels, in particular prostaglandins which can help prepare the uterus, and also make contractions start, but also a whole range of other side-effects.  A study looking at links between liquorice and low birth weight  found no link there, but did find a link with shorter pregnancies, i.e., mums who ate a lot of liquorice were twice as likely to have their babies before 38 weeks.
Probable efficacy: good. It is actually not recommended to eat liquorice during pregnancy for this reason and there are some other issues that mean you should probably steer clear. As for eating a bunch of it to bring on labour, I couldn’t find any studies and so dosage is unclear. As the side effects can be quite wide-reaching, then it is probably best to avoid, even if the effects may well help to bring on labour. Proceed with caution.
Or in the US, Eggplant, is famously used by a restaurant in America who swear women who eat it go into labour within 48 hours! 
Probable efficacy: poor. Probably complete tosh and no studies to prove either way. The general consensus on the web is that it is the basil and oregano in the recipe and not the aubergine itself. (These will be covered in the section on Aromatherapy.)
Dates are full of minerals, nutrients and amino acids and have been proven, when consumed in the last 4 weeks of pregnancy, to significantly reduce the need for induction or augmentation of labour and shorten the first stage of labour , and in a different study  helped reduce postpartum haemorrhage. Not sure exactly why but dates seem to have a similar effect on the body as oxytocin and have been widely used historically in Africa for this purpose and they are mentioned in the Quran in the context of labour and birth.
Probable efficacy: medium. Proven to help your body to prepare for labour and so more likely to go into labour spontaneously, it is not clear if just eating a huge amount to induce labour will do anything other than give you a good clear out! Won’t do you any harm but best to take for a few weeks.
This is probably the most controversial of all the methods. Back in the day (!) it was very popular and to be fair, research does suggest it is quite effective.  But be warned: it is unpleasant and the risks to your baby are not known. Essentially it either makes you vomit profusely, or gives you rocking diarrhoea (this seems to be a bit of a repeating theme), or worse, both. The all-body muscle contractions of vomiting are a way of kick-starting the uterus. Once you have expelled the castor oil, the vomiting should stop but it is clearly unpleasant and frankly a bit too drastic for me. Another study  has shown it is not effective in the least – but still unpleasant. And another still that it is very effective .
Probably efficacy: good (but don’t try it). You are only supposed to take a small dose, although I have heard or read stories of people who drink half a bottle. It is really not recommended and, in fact, most pharmacists won’t sell it to a pregnant lady.
RASPBERRY LEAF TEA
Raspberry leaf is a herbal extract that comes in the form of a tea (tastes a bit like Rosehip and Hibiscus) or tablets. You can get it from Health Food stores or online. It can be taken from 32 weeks in pregnancy. It is supposed to help prepare the soft tissues around the birth canal through oxytocin-like properties which is why it is taken many weeks in advance, and thus helps shorten labour. It is also supposed to help with breastfeeding in the post-natal period.
Probable efficacy: medium. There are studies that basically show it makes no difference whatever , but also does no harm! The NCT are happy to sell it though so it can’t hurt, but probably does nothing. There seem to be 2 camps on the breastfeeding issue: one says it helps, the other says avoid it but as this post is about labour and birth we’ll leave that for another day!
EVENING PRIMROSE OIL
Evening primrose is oil made from the seeds of the evening primrose plant. It contains prostaglandins, the hormone associated with helping the cervix soften and ripen in preparation for labour. You can take it orally, and as a pessary, from 34 weeks and it is said to help get your uterus and vagina ready for birth. As it is also in oil form it can be used to aid perineal massage to help soften the vaginal tissues.
Probable efficacy: poor. The oils probably does help to soften the tissues but there are, again, no studies proving any kind of link. In fact I found one article that explained that one study of oral EPO show that, “it doesn’t work as we thought it did and it offers considerable risks. The other study found that it does result in some cervical ripening, but that did not translate into shorter pregnancies or labors.”  Clearly more study is required and on balance, perhaps not such a great idea.
This is a North American herbal remedy in the form of a tincture which is not recommended during pregnancy because of the way it can induce labour. Blue cohosh seems to have a similar effect as oxytocin and stimulates uterine activity depending on the dosage.
Probable efficacy: good (but don’t use it). There are some nasty side effects (like increased heart rate) and has been cited in having severely bad effects on newborns so although appears to be effective it is best avoided due to these associated risks , however it has been widely used by midwives but studies do show it can have toxic effects. 
In fact quite unrelated to blue cohosh, this tincture is also taken, like raspberry leaf, in small doses in the third trimester to prime the uterus for labour, and then post-term in larger doses to induce labour. It is again a North American herb and used in many remedies. Midwives use it extensively – some in combination with blue cohosh. Thought to help induction due to oestrogen-type behaviour on the body. 
Probable efficacy: medium. Due to other side effects and the clear effect it can have on the body – both positive and negative  – it is probably best to avoid unless recommended by a midwife or practitioner.
There are those who thing homepathy is a big joke, and others who swear by it. Who am I to judge? But homeopaths will certainly have a range of things on offer for pregnancy and labour/birth. Each treatment is tailored to the individual so you should speak to a homeopath to find out more.
Probably efficacy: medium. Again, on the fence with this one, and studies often sit on the fence as well . Probably not going to hurt you but advisable not to self-medicate on this front and advice from a qualified practitioner should prevail.
So, there are many ways of eating your way into labour but the most effective seem to have such risks or nasty side-effects that it is hard to recommend them. Back to the drawing board? Here is the original post...
1. There seems to be a consensus that you need to eat 7 pineapples but after a few hours research I have been unable to find an academic source for this amount. Life is too short to spend any more time on it but here is the most academic citation I could find that states it so she probably has a source!
2. Purely anecdotal, no-one has even bothered studying this!
5. Restaurant claiming to help in the start of labour!
6. Recipe for above meal
7. Only the abstract as I can’t access the full article but all the key info here. http://www.ncbi.nlm.nih.gov/m/pubmed/21280989/
Evening Primrose Oil