Drinking alcohol when pregnant has been shown to be associated with reduced risk of having high blood pressure disorders during pregnancy. However, given that the opposite is true outside of pregnancy, that drinking alcohol is associated with increased blood pressure and risk of stroke and heart attack, the effect in pregnancy may be a result of other factors, not alcohol itself. We aim to use the Avon Longitudinal Study of Parents and Children (ALSPAC) to compare women who drank alcohol during their pregnancy and those who didn't, to see if drinkers were more likely to develop high blood pressure disorders during pregnancy than non-drinkers. We also aim to use information on partner's alcohol use during pregnancy and mum's risk of these disorders, to try and understand if the effect seen in mum is caused by alcohol or whether it is related to other factors shared by mum and her partner. In other words, given that a partner's drinking can't have a physical effect on mum's risk of these disorders, if we see a decreased risk when comparing drinking and non-drinking partner's, we can assume that maybe there are other factors shared by both mum and partner that is causing the reduced risk, not the alcohol itself.