| Sub-classification | Description |
| O99.0 |
Anaemia complicating pregnancy, childbirth and the puerperium |
| O99.1 |
Other diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism complicating pregnancy, childbirth and the puerperium |
| O99.2 |
Endocrine, nutritional and metabolic diseases complicating pregnancy, childbirth and the puerperium |
| O99.3 |
Mental disorders and diseases of the nervous system complicating pregnancy, childbirth and the puerperium |
| O99.4 |
Diseases of the circulatory system complicating pregnancy, childbirth and the puerperium |
| O99.5 |
Diseases of the respiratory system complicating pregnancy, childbirth and the puerperium |
| O99.6 |
Diseases of the digestive system complicating pregnancy, childbirth and the puerperium |
| O99.7 |
Diseases of the skin and subcutaneous tissue complicating pregnancy, childbirth and the puerperium |
| O99.8 |
Other specified diseases and conditions complicating pregnancy, childbirth and the puerperium |