It may be time to put down your flat white, because women who are pregnant or trying for a baby should avoid all caffeine, new research suggests.
Maternal caffeine consumption is “associated with negative pregnancy outcomes” and there is “no safe level of consumption”, according to a new analysis of studies published in BMJ Evidence Based Medicine.
But other experts have said the paper is “overly alarmist”, arguing that the occasional tea or coffee is unlikely to harm an unborn baby.
Currently, major health bodies advise pregnant women to moderate their caffeine consumption, but say that consuming a small amount of caffeine daily is not harmful.
The NHS, the American College of Obstetricians and Gynaecologists, the Dietary Guidelines for Americans and the European Food Safety Authority (EFSA) all set this level at 200mg caffeine, which is roughly two cups of moderate-strength coffee per day.
The latest review, led by Professor Jack James, from Reykjavik University, Iceland, disagrees. Prof. James looked at 48 observational studies on the topic, linking caffeine consumption to six major negative pregnancy outcomes: miscarriage, stillbirth, low birth weight and/or small for gestational age, preterm birth, childhood acute leukaemia, and childhood overweight and obesity.
As this was an observational study, it can’t establish causation, and Prof. James points out that the results could be impacted by other factors, such inaccurate recall of caffeine consumption, cigarette smoking and pregnancy symptoms.
Still, from the possible links identified, Prof. James believes the current health recommendations concerning caffeine consumption during pregnancy are in need of “radical revision.”
“Specifically, the cumulative scientific evidence supports pregnant women and women contemplating pregnancy being advised to avoid caffeine,” he says.
Dr Luke Grzeskowiak, a pharmacist at the University of Adelaide, Australia, disagrees and called the research paper “overly alarmist”.
“There are so many dos and don’ts associated with pregnancy and the last thing we need is to cause unnecessary anxiety,” he told the BBC. “At the end of the day, women should be reassured that caffeine can be consumed in moderation during pregnancy.”
Prof Andrew Shennan, professor of obstetrics at Kings College London, added that the official guidelines are “unlikely to change” as a result of the study.