Table 1.
Demographic characteristics and NNNS summary cores for participants with completed SRS measures through 5 and through 8 years.
| Participants with NNNS (n = 355) | Follow-up through 5 years (n = 214) | Follow-up through 8 yearsb (n = 227) | |
|---|---|---|---|
| Maternal characteristics at baseline a | |||
| Maternal age at delivery (years) | 29.7 (5.7) | 29.6 (5.6) | 29.3 (5.9) |
| Race (African American) | 107 (30.1) | 64 (29.9) | 74 (32.6) |
| Married | 237 (66.8) | 148 (69.2) | 147 (64.7) |
| Household Income, midpoint ($K) | 59.5 (41.8) | 59.5 (40.5) | 57.4 (41.8) |
| Employed during pregnancy | 293 (82.5) | 183 (85.5) | 192 (84.6) |
| Baseline Beck Depression Inventory | 9.6 (6.8) | 9.4 (6.4) | 9.8 (6.3) |
| Never drank alcohol during pregnancy | 196 (55.2) | 125 (58.4) | 124 (54.6) |
| Daily cigarettes smoked in pregnancy | 0.5 (2.2) | 0.4 (2.2) | 0.5 (2.4) |
| Maternal max serum cotinine delivery (ng/mL) | 6.6 (32.3) | 4.7 (28.1) | 6.2 (30.5) |
| Infant characteristics | |||
| Male | 166 (46.8) | 95 (44.4) | 98 (44.8) |
| Birth weight (grams) | 3388.4 (611.7) | 3380.8 (621.8) | 3314.5 (637.2) |
| Ponderal index | 2.5 (0.3) | 2.5 (0.3) | 2.5 (0.3) |
| Gestational age (weeks) | 39.0 (1.7) | 39.1 (1.7) | 38.9 (1.9) |
| Gestational age <37 weeks | 31 (8.7) | 17 (7.9) | 23 (10.1) |
| Gestational age at exam (weeks) | 43.9 (2.0) | 43.9 (2.0) | 43.8 (2.1) |
| Nulliparous | 155 (43.7) | 103 (48.1) | 104 (45.8) |
| NICU stay (yes) | 17 (4.8) | 11 (5.1) | 15 (6.6) |
| NNNS summary scale scores | |||
| Attention | 5.4 (1.4) | 5.4 (1.4) | 5.3 (1.4) |
| Regulation | 5.5 (0.8) | 5.5 (0.8) | 5.5 (0.81) |
| Quality of movement | 4.8 (0.6) | 4.8 (0.6) | 4.8 (0.6) |
| Habituationc | 6.3 (2.0) | 6.2 (2.1) | 6.1 (2.0) |
| Lethargy | 4.2 (1.7) | 4.1 (1.8) | 4.2 (1.7) |
| Asymmetric reflexes | 1.3 (1.1) | 1.2 (1.1) | 1.2 (1.1) |
| Excitability | 2.4 (2.0) | 2.4 (2.0) | 2.4 (2.0) |
| Handling | 0.4 (0.3) | 0.45 (0.31) | 0.45 (0.31) |
| Non-optimal reflexes | 3.9 (1.7) | 4.0 (1.6) | 3.9 (1.6) |
| Hypertonia | 0.04 (0.20) | 0.04 (0.21) | 0.04 (0.2) |
| Hypotonia | 0.27 (0.52) | 0.28 (0.55) | 0.26 (0.52) |
| Stress abstinence | 0.1 (0.05) | 0.13 (0.05) | 0.13 (0.06) |
| Arousal | 4.2 (0.7) | 4.2 (0.7) | 4.1 (0.7) |
Note. NNNS Domains Scale range: Attention, Regulation, Quality of Movement, Habituation, Arousal = 1–9; Hypertonia, Hypotonia 0–10; Lethargy, Excitability, Non-optimal Reflexes = 0–15; Asymmetric Reflexes = 0–16; Handling, Stress Abstinence = 0–1.
Values presented are means (SDs) for continuous variables and numbers (percent) for categorical variables.
Attended 8-year visit regardless of attendance at 4- or 5-year visit.
Infants must be asleep for this task, reducing the number of available results (n = 20 at through 5 y; n = 16 at 8 y).
NNNS: Neonatal Intensive Care Unit Network Neurobehavioral Scale; NICU: Neonatal Intensive Care Unit; SRS: Social Responsiveness Scale; n: number; y: years; ng/mL: nanograms per milliliter; $K: US dollars in thousands; SDs: standard deviations.