Table 2.

Distribution of Characteristics of Children Born in WA 1999-2013 by Maternal IDD Diagnosis Status

	All Births		No IDD Diagnosis		IDD Diagnosis
	N = 1,271,419		N = 1,270,852		N = 567
	n	%	n	%	n	%	X2
Race/Ethnicity							71.60***
White	840,356	66.1	839,917	66.1	439	77.4
Hispanic	203,385	16.0	203,333	16.0	52	9.2
Other/Unknown	18,644	1.5	18,632	1.5	12	2.1
Asian/Pacific Islander	120,485	9.5	120,472	9.5	13	2.3
Black	59,762	4.7	59,736	4.7	26	4.6
Native American	28,787	2.3	28,762	2.3	25	4.4
Maternal Age							8.17*
< 19 years	102,940	8.1	102,882	8.1	58	10.2
20-24 years	295,316	23.2	295,167	23.2	149	26.3
25-29 years	361,060	28.4	360,904	28.4	156	27.5
30+ years	511,562	40.3	511,358	40.3	204	36.0
Insurance Type							54.84***
Public	444,914	35.0	444,630	35.0	284	50.1
Private	826,505	65.0	826,222	65.0	283	49.9
Prenatal Care							3.65
1st trimester	666,769	52.4	666,480	52.4	289	51.0
2nd trimester	403,985	31.8	403,813	31.8	172	30.3
3rd trimester	70,231	5.5	70,194	5.5	37	6.5
None	130,434	10.3	130,365	10.3	69	12.2
Parity							33.78***
First birth	519,097	40.8	518,797	40.8	300	52.9
Non-first birth	752,322	59.2	752,055	59.2	267	47.1
Infant Birth Weight							30.85***
Low (<2500 g)	82714	6.5	82,644	6.5	70	12.3
Normal (2500+)	1,188,705	93.5	1,188,208	93.5	497	87.7

Note: missing values were not included in calculations of percentages; IDD = Intellectual disability diagnoses

^***p < .001,

^**p < .01,

^*p < .05