O30.0 - Twin pregnancy
O30.00 - Twin pregnancy, unspecified number of placenta and unspecified number of amniotic sacs
O30.001 - Twin pregnancy, unspecified number of placenta and unspecified number of amniotic sacs, first trimester
O30.002 - Twin pregnancy, unspecified number of placenta and unspecified number of amniotic sacs, second trimester
O30.003 - Twin pregnancy, unspecified number of placenta and unspecified number of amniotic sacs, third trimester
O30.009 - Twin pregnancy, unspecified number of placenta and unspecified number of amniotic sacs, unspecified trimester