A study has found that naturally occurring chemicals can affect your ability to use folic acid for foetal development is affected by naturally occurring chemicals in green tea. The tea, renowned for its health benefits, is lower in caffeine than both coffee and black tea which can make it appealing to mums-to-be trying to cut back on their caffeine.
However, because of the importance of folic acid in pregnancy, the researchers recommend pregnant mums reduce or stop drinking it completely.
Despite being natural and beneficial outside pregnancy, there are many herbal teas that should also be avoided during pregnancy, as the chemicals found in them can be harmful to mum or baby. These include raspberry leaf tea which can bring on labour (and is sometimes used in the last few weeks of pregnancy to encourage late babies), camomile, lemongrass and anise, amongst others.
If you are concerned, check the back of herbal tea packs for details or ask your midwife.