Many pregnant women love liquorice candies, mainly the black ones

Dr Timo Strandberg

"Many pregnant women love liquorice candies, mainly the black ones."

"The finding of liquorice and pre-term delivery makes biological sense, because liquorice may also boost prostaglandin production and thus hasten delivery.

"But we do not have any experimental evidence on that."

Dr Strandberg said they had asked 1,049 women to take part in the study, which quizzed them about their consumption of glycyrrhizin - the primary chemical component of black liquorice sweets.

Liquorice eaters had their babies 2.5 days earlier

The researchers also collected information on the birth weight of the babies, the delivery date and the due date.

The study was initially initiated to see whether the liquorice had any effect on the birth weight of babies.

Dr Strandberg said: "Contrary to our hypothesis, we did not detect any significant effect of maternal liquorice intake upon birthweight, but instead found a significant association of shorter gestational age with heavy intake of liquorice."