Table 2.

Distribution of delivery hospitalizations with and without severe maternal morbidity and rate of severe maternal morbidity by obstetric comorbidity index score—Massachusetts, 1998–2013

Obstetric comorbidity index score	Delivery hospitalizations			Rate of delivery hospitalizations with severe maternal morbidity
	No. without severe morbidity	No. with severe morbidity	Total		Per 10,000
0	689,465	1579	691,044	22.8
1	286,512	1139	287,651	39.6
2	130,842	919	131,761	69.7
3	41,257	520	41,777	124.5
4	13,468	330	13,798	239.2
5	10,799	425	11,224	378.7
6	4023	178	4201	423.7
7	2174	127	2301	551.9
8	873	61	934	653.1
9	307	25	332	753.0
10+	137	22	159	1383.6
Total	1,179,857	5325	1,185,182	44.9