Coffee: should I give it up while I’m trying to get pregnant?
The short answer is that decreasing your coffee intake is a good idea while you’re trying to get pregnant and through your pregnancy.
In 2017 two public health research groups in the UK published a wide-ranging review of coffee consumption and health benefits and risks. The review is titled ‘Coffee consumption and health: umbrella review of meta-analyses of multiple health outcomes’. Helpfully the article is open access, which means you can get the whole paper here if you’d like to have a look.
I’ll summarise their findings here. Firstly, a meta-analysis is often part of what is called a systematic review, which tries to answer a defined research question by collecting and summarising all the evidence that fits within that scope. The meta-analysis is the use of statistical methods to summarise the results of these studies. This can be helpful be giving us a robust single outcome, such as ‘is coffee beneficial?’ by combining the results from many smaller studies.
In the coffee study they included studies that examined the associations between coffee consumption and any health outcome in any adult population in all countries and all settings; so it was quite broad and they looked at hundreds of other meta-analyses on coffee and health outcomes.
Coffee during pregnancy
The results indicate that if you drink three or four cups a day you have about 30% higher risk of a low birth weight baby. There’s also around 20% higher risk of pre-term birth and a 50% higher risk of pregnancy loss.
The time it takes you to metabolise caffeine is known to double during pregnancy, so this means amount of caffeine from each coffee will be higher than when you’re not pregnant. That’s why the effects will be increased when you have multiple cups too. Caffeine is able to easily cross the placenta and your baby can’t metabolise it very well, so the effects are prolonged.
Coffee outside of pregnancy
The good news is that based on this study those of us drinking three to four cups a day have about 20% lower risk of death from all-causes mortality, versus non-coffee drinkers. A few cups a day also decreases cardiovascular disease, cancer and type II diabetes by about 15, 20 and 30% respectively.