Table 1.

Characteristics of the cohort of women with deliveries after 26 weeks gestational age by Tdap immunization status

	Total N=1,079,034		Optimal Prenatal N=123,780		Early Prenatal N=25,037		Postpartum N=59,040		None N=871,177
Mean Age, mean (SD)	29.2	5.4	29.6	5.1	29.4	5.2	28.9	5.3	29.2	5.4
Year
2010 n, %	182,828	16.9	1,189	1.0	462	1.9	5,942	10.1	175,235	20.1
2011 n, %	236,606	21.9	2,512	2.0	2,673	10.7	14,906	25.3	216,515	24.9
2012 n, %	254,731	23.6	12,094	9.8	4,963	19.8	17,630	29.9	220,044	25.3
2013 n, %	188,043	17.4	34,714	28.0	7,610	30.4	10,342	17.5	135,377	15.5
2014 n, %	216,826	20.1	73,271	59.2	9,329	37.3	10,2 20	17.3	124,006	14.2
Preterm n, %	79,677	7.4	6,154	5.0	2,593	10.4	3,962	6.7	66,968	7.7
Other covered children on plan, mean (SD)	1.6	1.2	1.5	1.1	1.5	1.1	1.6	1.1	1.7	1.2
Received obstetric blood panel* n, %	587,342	54.4	68,887	55.7	14,168	56.6	35,906	60.8	468,381	53.8
Received ultrasound* n, %	853,745	79.1	109,157	88.2	22,517	89.9	48,400	82.0	673,671	77.3
Received flu immunization n, %	239,593	22.2	59,932	48.4	12,919	51.6	12,384	21.0	154,358	17.7
Hospitalizations, mean (SD)*	0.01	0.01	0.01	0.09	0.01	0.11	0.01	0.11	0.01	0.11
Emergency department visits, mean (SD)*	0.21	0.67	0.19	0.61	0.22	0.71	0.22	0.67	0.21	0.67
Lives in MSA n, %	917,056	85.0	107,713	87.0	21,784	87.0	50,285	85.2	737,274	84.6
Missing n, %	28,150	2.6	3,942	3.2	796	3.2	1,573	2.7	21,839	2.5
Region
Northeast n, %	169,749	15.7	19,300	15.6	3,634	14.5	7,943	13.5	138,872	15.9
Midwest n, %	257,559	23.9	32,881	26.6	5,790	23.1	12,951	21.9	205,937	23.6
South n, %	392,581	36.4	35,264	28.5	6,509	26.0	23,531	39.9	327,277	37.6
West n, %	230,952	21.4	32,392	26.2	8,308	33.2	13,041	22.1	177,211	20.3
Unknown n, %	28,193	2.6	3,943	3.2	796	3.2	1,574	2.7	21,880	2.5
Maternal hypertension n, %	151,135	14.0	17,927	14.5	3,489	13.9	8,070	13.7	121,649	14.0
Diabetes mellitus n, %	19,751	1.8	2,060	1.7	411	1.6	952	1.6	16,328	1.9
Gestational Diabetes n, %	152,059	14.1	18,372	14.8	3,533	14.1	8,461	14.3	121,693	14.0
Kidney dysfunction n, %	2,203	0.2	266	0.2	52	0.2	75	0.1	1,810	0.2
Lupus n, %	2,415	0.2	271	0.2	64	0.3	104	0.2	1,976	0.2
Antihypertensive use n, %	36,684	3.4	3,631	2.9	769	3.1	1,902	3.2	30,382	3.5
Antidiabetic use n, %	30,485	2.8	4,262	3.4	850	3.4	1,469	2.5	23,904	2.7
SSRI use n, %	34,674	3.2	4,749	3.8	919	3.7	1,774	3.0	27,232	3.1
Antibiotic use n, %	298,282	27.6	34,519	27.9	6,927	27.7	17,050	28.9	239,786	27.5
Matched to baby n, %	677,075	62.8	80,217	64.8	16,322	65.2	36,630	62.0	543,906	62.4

^*assessed from pregnancy onset to 20 weeks

Abbreviations: Tdap, tetanus-diphteria-acellular pertussis immunization; SD, standard deviation; MSA, metropolitan statistical area; SSRI, serotonin selective reuptake inhibitor.