Obstetric Comorbidity Scoring System

Below is information to implement the obstetric comorbidity scoring system in a data set that includes ICD-CM codes and patient age. As an example, a patient with ICD-CM codes indicating preexisting cardiac disease and chronic hypertension would receive comorbidity scores of 17 for SMM risk (14+3) and 31 for non-transfusion SMM risk (25+6). (Note that the scores for SMM and non-transfusion SMM cannot be directly compared as they were developed separately.) The goal for these scoring systems is to facilitate improved comparisons of SMM rates and non-transfusion SMM rates between groups of patients.

Risk scores for comorbidities in relation to severe maternal morbidity (SMM) and non-transfusion SMM

Comorbidity

Score for
SMM

Score for non-
transfusion SMM

Placenta accreta spectrum
27 43
Pulmonary hypertension 20 33
Chronic renal disease 17 30
Cardiac disease, preexisting 14 25
HIV/AIDS 13 13
Preeclampsia with severe features 12 18
Placental abruption 9 13
Bleeding disorder, preexisting 9 11
Anemia, preexisting 9 6
Twin/multiple pregnancy 9 5
Preterm birth (< 37 weeks) 8 13
Placenta previa, complete or partial 8 3
Neuromuscular disease 6 13
Asthma, acute or moderate/severe 5 12
Preeclampsia without severe features or gestational hypertension 5 7
Connective tissue or autoimmune disease 4 8
Uterine fibroids 4 7
Substance use disorder 4 4
Gastrointestinal disease 3 7
Chronic hypertension 3 6
Major mental health disorder 3 4
Preexisting diabetes mellitus 2 6
Thyrotoxicosis 3 2
Previous cesarean birth 2 0
Gestational diabetes mellitus 1 2
Delivery BMI > 40 1 0
Maternal age > 35 years 0 1

 

 

Diagnosis codes for comorbidities in relation to severe maternal morbidity (SMM) and non-transfusion SMM
Comorbidity ICD-9-CM diagnosis codes ICD-10-CM diagnosis codes
Placenta accreta spectrum

Use algorithm: no uterine rupture

(665.0, 665.10, 665.11) PLUS (placenta previa (641.01, 641.11) or retained placenta (666.0, 667.x)) PLUS hysterectomy (PR 68.3-68.9)

O43.213, O43.223, O43.233
Pulmonary hypertension 416.0, 416.8, 416.9 I27.0, I27.2
Chronic renal disease 581-583, 585, 587, 588, 753, 250.4 249.4, 710.0 O26.83, I12, I13, N03-N05, N07, N08, N11.1, N11.8, N11.9, N18, N25.0, N25.1, N25.81, N25.89, N25.9, N26.9
Cardiac disease, preexisting 394-397, 402-405, 412-414, 416.2, 416.8, 416.9, 428.22, 428.23, 428.32, 428.33, 428.42, 428.43, 745, 746, 648.5, 648.60-648.63, 426, 427.0-427.4, 427.6-427.9 I05-I09, I11-I13, I15, I16, I20, I25, I27.8, I31, I32, I34-I39, I44, I45, I47-I49, I50.22,  I50.32, I50.33, I50.42, I50.43, I50.812, I50.813 O99.41, O99.42, Q20-Q24
HIV/AIDS 042, V08 O98.7, B20
Preeclampsia with severe features 642.5 O14.1, O14.2, O11
Placental abruption 641.2 O45
Bleeding disorder, preexisting 286.0-286.5, 286.7, 287 D66, D67, D68.0-D68.6, D69
Anemia, preexisting

280.0, 280.1, 280.9, 285.9, 280.8, 281, 282.0, 282.1, 282.3, 282.40, 282.41, 282.43, 282.44, 282.45, 282.46, 282.47, 282.49, 282.5, 282.60, 282.61, 282.63, 282.68, 282.7, 282.8, 282.9, 284, 285, 648.20, 648.21, 648.22, 628.23

O99.01, O99.02, D50-53, D55, D56, D58, D59, D57.1, D57.20, D57.3, D57.40, D57.80, D64.9

Twin/multiple pregnancy 651, V27.2-V27.71 O30, O31, Z37.2-Z37.7
Preterm birth (< 37 weeks) Birth certificate (644.21 if not available) Z3A.20-Z3A.36
Placenta previa, complete or partial 641.01, 641.11 O44.03, O44.13, O44.23, O44.33
Neuromuscular disease 345, 358 G40, G70
Asthma, acute or moderate/severe 493 O99.5, J45.21, J45.22, J45.31, J45.32, J45.4, J45.5, J45.901, J45.902
Preeclampsia without severe features or gestational hypertension 642.3, 642.4, 642.7 O13, O14.0, O14.9
Connective tissue or autoimmune disease 710, 714, 279.4 M30-M36
Uterine fibroids 218, 654.1 D25, O34.1
Substance use disorder 291, 303, 304, 305, 648.30, 648.31, 648.32, 648.33 F10-F19, O99.31, O99.32
Gastrointestinal disease 539, 555-558, 570-579, 564, 646.7 K50-K52, K70-K77, K80-K83, K85-K87, K94, K95, O26.6
Chronic hypertension 401-405, 642.0-642.2, 642.7 O10, O11, I10
Major mental health disorder 295-298, 300.0, 300.21, 300.22, 300.4, 301, 309 F06, F20-F25, F28-F34, F39, F40.0, F41, F43, F53, F60
Preexisting diabetes mellitus 250, 648.0 E08-E13, O24.0, O24.1, O24.3, O24.8, O24.9, Z79.4
Thyrotoxicosis 242 E05
Previous cesarean birth 654.2 O34.21, O66.41
Gestational diabetes mellitus 648.8 O24.4
Delivery BMI > 40 Birth certificate - use code 278.01 if birth certificate not available Birth certificate – use Z68.4, E66.01, E66.2 if birth certificate not available
Maternal age > 35 Birth certificate/Discharge record Birth certificate/Discharge record

All parent codes subsume child codes (e.g., 493 means 493.xx) with exception of ICD-9-CM codes for twin gestation.Because V27.2xxx are ICD-10-CM codes for other conditions, we recommend only using V27.2-V27.3 without child codes included.