--- O10.911 Unspecified pre-existing hypertension complicating pregnancy, first trimester

--- O10.912 Unspecified pre-existing hypertension complicating pregnancy, second trimester

--- O10.913 Unspecified pre-existing hypertension complicating pregnancy, third trimester

--- O10.919 Unspecified pre-existing hypertension complicating pregnancy, unspecified trimester