A new study shows that having too much caffeine during pregnancy may impair a baby's liver development and increase the risk of liver disease in adulthood.
This study was published in the Journal of Endocrinology.
Pregnant rats given caffeine had offspring with lower birth weights, altered growth and stress hormone levels and impaired liver development.
The findings indicate that consumption of caffeine equivalent to 2-3 cups of coffee may alter stress and growth hormone levels in a manner that can impair growth and development, and increase the risk of liver disease in adulthood.
Previous research showed that prenatal caffeine intake of 300 mg/day or more in women, which is approximately 2 to 3 cups coffee per day, can result in lower birth weights of their children.
In this latest study, Prof Hui Wang and colleagues at Wuhan University in China, investigated the effects of low (equivalent to 2-3 cups of coffee) and high doses (equivalent of 6-9 cups of coffee) caffeine, given to pregnant rats, on liver function and hormone levels of their offspring.
Offspring exposed to prenatal caffeine had lower levels of the liver hormone, insulin like growth factor (IGF-1), and higher levels of the stress hormone, corticosteroid at birth. However, liver development after birth showed a compensatory "catch-up" phase, characterised by increased levels of IGF-1, which is important for growth.
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," adds Wen.