Table 2.

The rate of multiples, singleton preterm births (<37 weeks) and singleton SGA births (<10th percentile) among ART users by state of residence and maternal characteristics for 2000 to 2006^b

	ART multiples				ART singleton preterm				ART singleton SGA
Maternal characteristics	Florida (n = 3093) (%)	Massachusetts (n = 3969) (%)	Michigan (n = 1962) (%)	P-value	Florida (n = 808) (%)	Massachusetts (n = 936) (%)	Michigan (n = 483) (%)	P-value	Florida (n = 492) (%)	Massachusetts (n = 761) (%)	Michigan (n = 311) (%)	P-value
Maternal age (years)
<30	41.3	35.6	37.1	0.026	14.0	11.8	12.3	0.476	7.8	9.4	8.4	0.594
30–34	36.5	33.1	36.7	0.001	13.5	9.9	11.3	<0.001	8.3	7.9	7.1	0.455
35–39	31.9	28.9	32.1	0.003	12.5	9.9	14.2	<0.001	8.9	8.3	8.8	0.700
≥40	31.1	25.0	29.4	<0.001	16.4	10.5	14.0	<0.001	7.8	8.2	9.6	0.414
Education
No college	35.1	29.2	33.9	0.002	14.8	11.8	13.4	0.143	8.7	9.0	8.2	0.841
Some college	34.6	31.9	33.9	0.130	15.8	9.3	13.3	<0.001	8.0	8.4	8.0	0.903
College degree	33.7	30.4	35.1	<0.001	12.4	10.1	11.9	0.014	8.0	7.6	8.0	0.783
Postgraduate	34.9	28.7	33.9	<0.001	12.7	10.1	13.4	0.005	8.7	8.7	8.7	0.997
Race/Ethnicity
NH white	34.5	30.2	34.5	<0.001	12.9	9.7	12.6	<0.001	7.4	7.8	7.9	0.654
NH black	37.0	31.6	30.9	0.172	24.0	19.8	13.2	0.045	15.4	10.1	14.9	0.171
Hispanic	33.3	29.4	–a	14.4	10.6	–a	9.4	8.6	–a
Other	34.7	27.2	29.6	0.027	11.4	12.2	17.3	0.178	10.3	13.7	10.7	0.305
Nativity
US	34.3	30.1	34.3	<0.001	13.8	10.0	12.8	<0.001	7.8	7.6	7.9	0.798
Non-US	34.8	29.6	33.5	0.002	13.3	11.2	13.1	0.220	10.1	12.1	11.0	0.266
Marital Status
Married	34.4	30.2	34.3	<0.001	13.6	10.2	12.8	<0.001	8.3	8.2	8.2	0.954
Single	35.4	26.2	30.8	0.015	15.4	8.4	14.9	0.019	8.4	9.1	9.5	0.938
Prenatal care (Kotelchuck)
<Adequate	16.0	16.0	17.0	0.885	7.4	8.7	10.8	0.180	8.3	6.8	6.3	0.393
Adequate	16.8	10.9	12.7	<0.001	6.6	2.5	5.6	<0.001	7.8	7.1	6.7	0.382
Adequate+	47.7	43.5	49.2	<0.001	20.9	17.8	20.9	0.002	9.0	9.6	10.4	0.342

^aMasked due to small cell sizes.

^bCells may not add up to 100% as missing values were not deleted.