Appendix 1.

Diagnosis or procedure and ICD-9 codes for markers of severe maternal morbidity^a

Morbidity Group	ICD-9 code
Diagnosis-based
Acute renal failure	584; 586; 669.30, 2, 4
Liver failure	570
Respiratory failure	518.4; 518.5; 518.81,2,4; 799.1
Obstetric shock	669.10,1,2,3,4
Cerebrovascular accident	430; 431; 432; 433; 434; 436; 671.50,1,2,3,4; 674.00,1,2,3,4
Pulmonary embolism	673.00,1,2,3,4; 673.20,1,2,3,4; 673.30,1,2,3,4; 673.80,1,2,3,4; 415.11; 415.19
Amniotic fluid embolism	673.10,1,2,3,4
Eclampsia	642.60,1,2,3,4
Septicemia	038
Complications of anesthesia	668.00,1,2,3,4; 668.10,1,2,3,4; 668.21,1,2,3,4
Procedure-based
Cardiac events/procedures	428; 425; 427.5; 410; 99.60; 99.62; 99.63; 99.64; 99.69
Mechanical ventilation	96.70; 96.71; 96.72
Transfusion	99.03; 99.04
Hysterectomy	68.3; 68.4; 68.9
Invasive hemodynamic monitoring	89.60–64

^aAdapted from Callaghan et al, 2008³