Tommy's responds to news about consuming caffeine during pregnancy

Alarming headlines were published today based on a study from Iceland, claiming that pregnant women should cut out coffee and other products containing caffeine completely. The headlines claimed that cutting out caffeine entirely would lower the risk of negative pregnancy outcomes, including miscarriage, preterm birth, low birth weight and stillbirth. The claims follow the publication of an Icelandic research paper in the British Medical Journal (BMJ), which looked at 48 existing studies, and concluded that there is no safe level of caffeine to consume during pregnancy.   

It’s important to remember that this is not new research, instead the study looked at existing research and made some conclusions which are controversial. Official advice from the NHS, the Royal College of Obstetricians and Gynaecologist (RCOG) and from Tommy’s, remains that women should reduce their caffeine intake when trying for a baby, or when pregnant, to less than 200 mg a day.  

200mg is about the same as consuming one bar of plain chocolate and one mug of filter coffee, or two mugs of tea and one can of cola per day. This advice has been given to all women up until this point by health professionals. Please remember that by following official guidelines, you have been doing your best to look after the health of your baby.  

It is also important to remember that this is not new, high-quality research, but an observational study pulling together lots of different data sets and results. This means it cannot directly link caffeine (by itself) to any negative outcomes observed. Prof Andrew Shennan, Clinical Director at Tommy's Preterm Surveillance Clinic at St Thomas' Hospital, said some of the studies that were included may be problematic. He also explained that it is difficult to remove other risk factors that the people included in the study may have had, such as smoking or alcohol consumption. 

"Caffeine has been in human diets for a long time. Like many substances found in a normal diet, harms in pregnancy can be found with high doses. However, the observational nature of this data with its inherent bias does not indicate with any certainty that low doses of caffeine are harmful, and the current advice to avoid high doses of caffeine are unlikely to change." Prof Andrew Shennan, Clinical Director at Tommy's Preterm Surveillance Clinic at St Thomas' Hospital

More research is needed before any official guidance changes on caffeine intake and its possible effects, and the way any new research findings are shared needs to be carefully considered so it doesn't unduly alarm or worry women. Tommy’s Research Centre in Manchester is currently undertaking research to explore this subject further. We will be publishing the results of our research later in the year, to provide women with evidence-based information, to help them make informed choices about their lifestyle during pregnancy.  

Please remember that caffeine consumption is one aspect of having a healthy pregnancy along with things like healthy eating, being active, and monitoring any unusual symptoms closely. Despite the alarming headlines, the risk from consuming caffeine remains low. This research should not cause undue worry or distress to parents.

If you are worried that you may have been consuming more than the recommended amount (200 mg), you can find out about your intake using our caffeine calculator. If after using our calculator, you are worried that your intake is high, please be assured that there are simple changes that you can make today that will have a positive and immediate impact on your health, and the health of your baby.   

Watch this BBC 5 Live interview with Professor Andrew Shennan, talking about the new study: 

Caffeine in common drinks and foods 

Here are some common foods and drinks that contain caffeine: 

• A can of cola has around 40mg of caffeine 
• A mug of tea has around 75mg 
• A bar of plain chocolate has around 50mg 
• A cup of instant coffee has around 100mg 
• A mug of filter coffee has around 140mg 
• Energy drinks: a 250ml can has around 80mg. 

Decaffeinated tea and coffee, fruit juice or water are all good replacements if you are used to drinking a lot of caffeinated drinks. Try to limit the amount of energy drinks you have, as they can be high in caffeine. 

Find out more about caffeine on our website.  

Support for parents who have been through baby loss 

If you have previously lost a baby and haven’t been given a reason why, you may find this research upsetting and start blaming yourself for consuming caffeine. This is natural when you are grieving and haven’t been given a reason for your loss. But try to remember that it is not your fault. The advice to stay below 200 mg of caffeine continues to be issued by the NHS, and you should not feel guilty. Please contact our midwives if the research has caused you distress, they can reassure you and help you understand more about this research. You can contact them on [email protected] (Mon to Fri, 9am to 5pm).