1. O11 Pre-existing hypertension with pre-eclampsia

    1. O11.1 Pre-existing hypertension with pre-eclampsia, first trimester

    2. O11.2 Pre-existing hypertension with pre-eclampsia, second trimester

    3. O11.3 Pre-existing hypertension with pre-eclampsia, third trimester

    4. O11.4 Pre-existing hypertension with pre-eclampsia, complicating childbirth

    5. O11.5 Pre-existing hypertension with pre-eclampsia, complicating the puerperium

    6. O11.9 Pre-existing hypertension with pre-eclampsia, unspecified trimester

Abbreviations used here:

NEC Not elsewhere classifiable
This abbreviation in the Tabular List represents “other specified”. When a specific code is not available for a condition, the Tabular List includes an NEC entry under a code to identify the code as the “other specified” code.

NOS Not otherwise specified
This abbreviation is the equivalent of unspecified.