Table 3.

Dual burden of severe maternal morbidity and preterm birth by sociodemographic and perinatal characteristics and insurance type, California, 2007–2012

Characteristic	Medi-cal		Private		Uninsured		Other insurancea
	n = 1,462,463		n = 1,431,956		n = 64,507		n = 100,149
	n	%	n	%	n	%	n	%
Overall	5541	0.38	5204	0.36	266	0.41	406	0.41
Sociodemographic characteristics
Maternal age
< 18	177	0.27	56	0.36	12	0.51	11	0.38
18–25	1920	0.29	613	0.24	86	0.47	94	0.26
26–35	2311	0.41	2429	0.30	95	0.30	187	0.41
> 35	1130	0.69	2100	0.58	73	0.59	113	0.74
Race/ethnicity
White, non-Hispanic	714	0.37	1889	0.33	58	0.67	112	0.36
Hispanic	3231	0.33	1458	0.35	124	0.38	141	0.36
Black, non-Hispanic	814	0.87	412	0.70	33	1.24	95	0.88
Asian, non-Hispanic	261	0.31	936	0.35	28	0.16	29	0.24
Other, non-Hispanic	521	0.47	509	0.48	32	1.05	29	0.39
Education
< 12 years	2201	0.36	338	0.41	87	0.60	67	0.42
12 years	1772	0.38	927	0.35	77	0.56	121	0.40
> 12 years	1267	0.39	3655	0.35	89	0.27	193	0.38
Urban/rural statusb
1 (most urban)	3316	0.38	3368	0.36	141	0.33	275	0.41
2	620	0.41	835	0.40	43	0.88	46	0.45
3	1228	0.37	778	0.35	58	0.95	67	0.35
4	242	0.34	150	0.32	13	0.38	8	0.30
5	88	0.41	32	0.25	5	0.98	2	0.36
6 (most rural)	24	0.29	15	0.28	3	1.61	2	0.90
Perinatal factors
Prenatal factors
Maternal pre-pregnancy body mass index
< 18.5	330	0.44	289	0.45	20	0.44	22	0.47
18.5–24.9	1986	0.34	2493	0.34	110	0.37	177	0.37
25.0–29.9	1316	0.35	1090	0.35	56	0.46	87	0.37
≥ 30	1331	0.41	905	0.39	40	0.54	80	0.42
Prenatal carec
Inadequate	1443	0.39	556	0.35	122	0.62	82	0.47
Intermediate	265	0.20	232	0.15	14	0.22	19	0.23
Adequate/adequate plus	3495	0.38	4238	0.39	117	0.33	274	0.38
Smoked during pregnancy
Yes	657	0.68	162	0.49	49	1.52	44	0.83
No	4884	0.36	5042	0.36	217	0.35	362	0.38
Pregnancy factors
Parity and mode of birth
Primiparous vaginal	457	0.13	462	0.11	20	0.10	23	0.11
Multiparous vaginal	783	0.13	540	0.10	41	0.17	43	0.11
Primiparous primary cesarean	1022	0.68	1592	0.74	57	0.69	102	0.84
Multiparous primary cesarean	1580	1.75	1597	1.88	69	2.00	132	2.08
Repeat cesarean	1696	0.73	1072	0.56	77	0.84	100	0.66
Pregnancy type
Singleton	4285	0.30	3156	0.23	217	0.35	269	0.28
Multiple gestation	1256	3.92	2048	3.51	49	2.85	137	4.40
Obstetric co-morbidities
Hypertension
No HTN	3186	0.24	2396	0.18	161	0.26	231	0.25
Preexisting HTN without preeclampsia	214	1.59	159	0.87	10	3.00	16	1.32
Preexisting HTN with preeclampsia	416	5.95	320	4.26	17	8.72	27	4.83
Gestational HTN without preeclampsia	166	0.53	150	0.46	8	0.73	13	0.54
Gestational HTN with preeclampsia	1226	2.58	1422	3.09	51	3.17	89	3.26
Diabetes
No diabetes	4531	0.34	4198	0.03	237	0.39	359	0.39
Preexisting diabetes	270	1.96	172	1.66	8	3.08	7	0.84
Gestational diabetes	740	0.62	834	0.63	21	0.62	40	0.59

Dual burden defined as concomitant severe maternal morbidity or maternal in-hospital death and preterm birth (< 37 weeks). Severe maternal morbidity was determined according to the CDC algorithm + birth certificate: 1) in-hospital deaths, regardless of length of stay; 2) #19–25 without regard to length of stay; 3) #1–18 and length of stay restriction, ≥ 90th percentile for type of birth with length of stay calculated separately for vaginal birth, primary cesarean, and repeat cesarean; and #1–25 on postpartum readmission regardless of length of stay)

BMI body mass index, HTN hyptertension

^aOther insurance includes: Indian Health Service, CHAMPUS or TRICARE, other local, state, or federal insurance, or charity

^bFederal Information Processing Standard categories

^cKotelchuck Adequacy of Prenatal Care Utilization Index (Harrison & Goldenberg, 2016)