Consuming large amounts of liquorice while pregnant can increase the risk of delivering the baby prior to full-term, according to scientists from the University of Helsinki, in Finland.

In a report, published in the June issue of American Journal of Epidemiology (2001; p153: pp1085-1088), the researchers explained that pregnant women who ate at least 250g of black liquorice every week were over twice as likely to go into labour before 38 weeks, an average of 2.5 days earlier than women who ate little or no liquorice.

To identify the levels of glycyrrhizin (the primary chemical component of black liquorice) consumption, 1049 women filled in questionnaires. The study was conducted in Finland because of the data available which suggested that liquorice was a favourite treat.

Speaking to Reuters Health, the study’s lead author Dr Timo E. Strandberg explained: “The finding of liquorice and pre-term delivery makes biological sense, because liquorice may also boost prostaglandin [a hormone often used to induce labour] production and thus hasten delivery.” It is also an important finding, given that “Pre-term delivery continues to be an obstetrical challenge and its mechanisms are still poorly understood. Our finding may give new ideas for this research.”

Strandberg added that the scientists initially sought to establish whether eating liquorice would affect an infant’s birth weight: “Theoretically liquorice could boost glucocorticoid metabolism in the placenta, and increase of glucocorticoids would lead to lower birth weight.” However, he added, “contrary to our hypothesis we did not detect any significant effect of maternal liquorice intake upon birth weight.”

The research team will now focus attention on conducting a case-control study on liquorice consumption in another hospital and “if this study confirms the present results, then I would tell pregnant ladies: be moderate with your liquorice consumption,” said Strandberg.

However, “I would hesitate to make any strong public health recommendations at this stage,” he added, “because ours is the only report on this subject.”