Table 1.

Summary Statistics: Texas Sibling Births 2005–2009

	WHOLE SAMPLE (N=612,694)		BIRTHS BY MOTHERS WITH WIC CLINIC IN ZIP CODE DURING ANY PREGNANCY (N=360,799)		BIRTHS WITH WIC CLINIC IN ZIP CODE DURING PREGNANCY (N=297,552)
	Mean	SD	Mean	SD	Mean	SD
Mother Received WIC Food During Pregnancy	0.556	0.497	0.647	0.478	0.656	0.475
Mother’s Age <20	0.150	0.357	0.178	0.383	0.179	0.384
Mother’s Age 20–24	0.330	0.470	0.370	0.483	0.365	0.481
Mother’s Age 25–34	0.447	0.497	0.399	0.490	0.401	0.490
Mother’s Age 35–44	0.073	0.260	0.053	0.224	0.055	0.227
Mother’s Ed: <HS	0.310	0.462	0.371	0.483	0.378	0.485
Mother’s Ed: HS degree	0.281	0.449	0.305	0.460	0.303	0.460
Mother’s Ed: Some College	0.220	0.415	0.207	0.405	0.203	0.402
Mother’s Ed: College+	0.188	0.391	0.117	0.321	0.116	0.320
Mother is Married	0.587	0.492	0.525	0.499	0.529	0.499
Mother is Non-Hispanic White	0.353	0.478	0.276	0.447	0.263	0.440
Mother is Black	0.110	0.312	0.107	0.310	0.098	0.297
Mother is Hispanic	0.511	0.500	0.601	0.490	0.624	0.484
Child is Male	0.511	0.500	0.510	0.500	0.510	0.500
Mother’s Pre-Pregnancy BMI	25.819	6.079	26.079	6.202	26.134	6.215
Pregnancy Weight Gain <16 lbs	0.146	0.354	0.159	0.366	0.161	0.368
Pregnancy Weight Gain >40 Lbs	0.191	0.393	0.186	0.389	0.183	0.387
Number Prenatal Visits	9.695	4.039	9.384	4.148	9.395	4.152
Prenatal Care Received from Public Clinic	0.092	0.289	0.106	0.308	0.109	0.311
Diabetes	0.035	0.183	0.034	0.180	0.034	0.181
Gestational Hypertension	0.043	0.202	0.041	0.199	0.041	0.199
Eclampsia	0.001	0.031	0.001	0.032	0.001	0.032
Birth Paid by Medicaid	0.480	0.500	0.554	0.497	0.553	0.497
Birth Weight (g)	3275.410	517.173	3254.084	517.108	3254.559	516.061
Low Birth Weight (<2500g)	0.060	0.238	0.064	0.245	0.063	0.244
Very Low Birth Weight (<1500g)	0.006	0.080	0.007	0.082	0.007	0.081
High Birth Weight (>4500g)	0.008	0.089	0.007	0.086	0.008	0.087
Gestation (weeks)	38.431	1.748	38.404	1.789	38.406	1.786
Premature (<37 weeks)	0.091	0.288	0.096	0.294	0.095	0.294
Child is Breastfed at Time of Discharge	0.745	0.436	0.710	0.454	0.709	0.454
Child Matched to Death Record	0.004	0.066	0.004	0.066	0.004	0.067

Notes: The sample is limited to singleton sibling births with mothers that reside in Texas over 2005–2009. Births with missing gestation length or gestation less than 26 weeks are omitted. Exposure to a WIC clinic is calculated by considering length of pregnancy from the time of conception (estimated using the child’s birth date and gestation length).