Table 3.

Rates of SMM, by Rural and Urban Residence, 2012 to 2014^*

SMM†	Rates per 10 000 Delivery Hospitalizations, Weighted‡			Rates per 100 Delivery Hospitalizations With Any SMM, Weighted, %‡
	All	Rural	Urban	All	Rural	Urban
Unweighted number	2 255 359	324 486	1 930 873	32 984	4797	28 187
Any SMM	146.2	147.8	146.0
With 1 SMM	-	-	-	85.38	87.70	84.99
With ≥2 SMMs	-	-	-	14.62	12.30	15.01
Specific SMM indicator
Blood transfusion	119.7	124.6	118.9	81.72	84.12	81.31
Disseminated intravascular coagulation	12.48	10.11	12.88	8.55	6.88	8.84
Hysterectomy	10.30	9.62	10.41	7.09	6.40	7.21
Adult respiratory distress syndrome	7.13	6.53	7.24	4.93	4.45	5.01
Acute renal failure	6.61	5.02	6.87	4.50	3.44	4.69
Sepsis	4.76	2.99	5.06	3.19	2.00	3.39
Shock	4.19	3.61	4.28	2.90	2.36	3.00
Eclampsia	3.82	3.91	3.81	2.66	2.69	2.65
Pulmonary edema/acute heart failure	3.43	2.84	3.53	2.37	1.93	2.44
Puerperal cerebrovascular disorders	1.53	0.92	1.64	1.06	0.62	1.13
Temporary tracheostomy or ventilation	1.49	1.14	1.55	1.00	0.77	1.04
Air and thrombotic embolism	1.25	1.51	1.21	0.88	1.03	0.85
Cardiac arrest or ventricular fibrillation or conversion of cardiac rhythm	1.05	1.14	1.03	0.75	0.80	0.70
Sickle cell anemia with crisis	0.87	0.28	0.97	0.58	0.15	0.66
Severe anesthesia complications	0.61	0.83	0.57	0.42	0.53	0.39
Heart failure/arrest during procedure or surgery	0.51	0.46	0.52	0.36	0.32	0.36
Amniotic fluid embolism	0.35	0.31	0.35	0.23	0.21	0.23
Acute myocardial infarction or aneurysm	0.32	0.34	0.32	0.23	0.24	0.23

SMM = severe maternal morbidity.

^*Delivery hospitalizations with missing values in rural/urban (0.9%) were excluded from this analysis.

^†All SMMs were identified by the Centers for Disease Control and Prevention’s list of 18 indicators from the International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis and procedure codes, with severity recalculation for implausibly short length of stay.

^‡Rates of SMM are in boldface if significantly different (P < 0.05) between rural and urban residents.