Table 1.
Birth status and demographic characteristics of EPT/ELBW and NBW groups.
| EPT/ELBW Group (n=148) |
NBW Group (n=111) |
|
|---|---|---|
| Birth Status and Neonatal Risk Factors: | ||
| Gestational age (GA) in weeks, mean (SD) and range |
25.9 (1.6), range: 23-32 weeks | >36 |
| Birth weight in grams, mean (SD) and range | 818.4 (174.0), range: 485-1281 g | 3382.3 (445.9), range: 2501- 4508 g |
| GA <25 weeks, n (%) | 32 (22%) | 0 (0%) |
| Birth weight <750 g, n (%) | 56 (38%) | 0 (0%) |
| Small for gestational agea | 37 (25%) | |
| Severely abnormal cranial ultrasound,b n (%) | 15 (10%) | 0 (0%) |
| Bronchopulmonary dysplasia (BPD),c n (%) | 77 (52%) | 0 (0%) |
| Infection or necrotizing enterocolitis,d n (%) | 60 (41%) | 0 (0%) |
| Severe retinopathy of prematurity,e n (%) | 27 (18%) | 0 (0%) |
| Demographic Characteristics: | ||
| Age in years at testing, mean (SD) | 5.96 (.37) | 5.96 (.31) |
| Months in school at testing, mean (SD)* | 4.25 (2.34) | 6.38 (1.72) |
| Male sex | 68 (46%) | 51(46%) |
| African Americanf | 91 (61%) | 61 (55%) |
| Maternal education: | ||
| < high school | 20 (14%) | 14 (13%) |
| high school or GED | 33 (22%) | 16 (14%) |
| > high school | 95 (64%) | 81 (73%) |
| Median family income,g mean (SD) | 59.10 (32.37) | 56.20 (23.67) |
| SES z-score composite,h mean (SD) | −0.05 (1.02) | 0.07 (0.98) |
Note: The majority of the sample (112, 76%) had GA <28 weeks and birth weight <1000 g, whereas 21 (14%) had GA <28 weeks with birth weight ≥1000 g and 15 (10%) had birth weight <1000 g birth weight with GA ≥28 weeks.
Abbreviations: EPT/ELBW= extremely preterm; NBW = term-born normal birth weight; GED = General Education Diploma; SES = socioeconomic status, with z-score defined as mean of sample z-scores for maternal education, caregiver occupation, and census-based median family income.
Small for GA as defined by birth weight <-2 SDs below expectation for GA based on standard reported by Yudkin et al. (1987). The high rate reported here partially reflects selection of children who were ≥28 weeks GA but who had birth weight <1000 g, all of whom were small for GA. The rate was lower for children with GA <28 weeks (17%) and consistent with rates reported in other studies (Fanaroff et al., 2007; Stoll et al., 2010).
Severely abnormal ultrasound defined as clinician-identified Grade III/IV intraventricular hemorrhage, periventricular leukomalacia, or ventricular dilatation at discharge.
BPD defined as supplemental oxygen at 36 weeks corrected age.
Includes 9 cases of necrotizing enterocolitis (6% of sample), 56 of septicemia (38%), and 2 of meningitis (1%).
Severe retinopathy defined as Stage 4 or 5 retinopathy or treatment with cryotherapy or laser therapy (Schmidt et al., 2003).
All others Caucasian except for 4 Asian (2 in each group).
Based on data on the neighborhood tract of the family residence from the 2000 US Census (Federal Financial Institutions Examinations Council Geocoding System, 2010). Family income is in thousands of dollars.
SES was measured by a composite of the sample z scores for maternal education, caregiver occupation.
Significant group difference, p<.01; group differences in gestation and birth weight by definition. All other differences non-significant.