Consultant Leonie replies: It's always important you're honest with your midwife or doctor about any drugs you've taken in early pregnancy. This includes prescription and over-the-counter medicine, as well as recreational drugs.
Women worry that health professionals will be judgmental, but midwives and doctors are trained to deal with these things and will ensure confidential information remains that way.
The use of recreational drugs in early pregnancy is surprisingly common so we have some idea what the risks are. Cannabis does not appear to be associated with a significant increase in the risk of birth defects.
However, studies have shown that cannabis used throughout pregnancy is associated with babies having a lower birth-weight than expected and also possible association with concentration problems in childhood. As any risks are likely to be what's called ‘dose related', the sooner you stop, the lower the risks will be.
Women who take cannabis may also smoke or take other types of recreational drugs. If that's the case, you must discuss strategies for stopping these with your midwife. Women using cannabis should not breastfeed, as the drug crosses into the milk.