A new study has discovered the dangers of consuming too much caffeine during pregnancy. Mums-to-be are advised to drink no more than 200mg of caffeine per day. 200mg is equal to two mugs of instant coffee or one mug of filter coffee.
However, expectant mums who drink more than the recommended 200mg are putting their baby at risk of liver disease.
Prof Hui Wang and colleagues at Wuhan University in China found that drinking 300mg or more can result in lower birth weights of babies.
The team analysed pregnant rats who were given low doses (equivalent to 2-3 cups of coffee) and high doses (equivalent of 6-9 cups of coffee) of caffeine. The researchers then tested the liver function and hormone levels of their offspring.
The offspring that were exposed to caffeine had lower levels of the liver hormone, insulin like growth factor (IGF-1), and higher levels of the stress hormone, corticosteroid at birth.
Dr Yinxian Wen, study co-author, says, "Our results indicate that prenatal caffeine causes an excess of stress hormone activity in the mother, which inhibits IGF-1 activity for liver development before birth. However, compensatory mechanisms do occur after birth to accelerate growth and restore normal liver function, as IGF-1 activity increases and stress hormone signalling decreases.
"The increased risk of fatty liver disease caused by prenatal caffeine exposure is most likely a consequence of this enhanced, compensatory postnatal IGF-1 activity."
Not only does caffeine exposure cause low birth weight and impaired liver development, but the findings also suggest there is a risk of baby suffering from liver disease in the future.
Dr Wen comments, "Our work suggests that prenatal caffeine is not good for babies and although these findings still need to be confirmed in people, I would recommend that women avoid caffeine during pregnancy."
This study was published in the Journal of Endocrinology.