Table 1.
Clinical neonatal and maternal antenatal characteristics, neonatal hippocampal volumes and 18‐month cognitive outcome by maternal level of education.
| High school | College/undergraduate | Postgraduate | p Value | |
|---|---|---|---|---|
| Clinical characteristics | n = 32 | n = 114 | n = 16 | – |
| Gestational age at birth (weeks), median (IQR) | 26.9 (25.9–28.8) | 26.7 (25.0–28.9) | 29.7 (27.4–30.4) | 0.016* |
| Birth weight (g), median (IQR) | 865 (660–1140) | 890 (700–1200) | 1200 (915–1555) | 0.026* |
| Male, no (%) | 12 (37.5) | 66 (57.9) | 11 (68.8) | 0.06 |
| Small for gestational age, no (%) | 4 (12.5) | 13 (11.4) | 3 (18.8) | 0.63 |
| APGAR score (5 min), median (IQR) | 7.5 (6.5–9) | 8 (6–9) | 8 (5–9) | 0.95 |
| Culture positive infection, no (%) | 8 (25) | 36 (31.6) | 4 (25) | 0.79 |
| Bronchopulmonary dysplasia, no (%) | 5 (15.6) | 45 (39.5) | 5 (31.3) | 0.038* |
| Major surgeries, no (%) | 7 (21.9) | 19 (16.7) | 0 | 0.13 |
| Retinopathy of prematurity, no (%) | 5 (15.6) | 5 (4.4) | 0 | 0.07 |
| Cumulative midazolam dose, mean (min–max) | 0 | 0.007 (0–0.18) | 0 | 0.87 |
| Maternal characteristics | ||||
| Maternal age, median (IQR) | 33 (25.5–36) | 33 (29–36) | 35 (33–40) | 0.026* |
| Maternal BMI, median (IQR) | 31.0 (27.7–35.9) | 26.9 (23.7–32.7) | 32.4 (26.3–33.4) | 0.16 |
| Maternal hypertension, no (%) | 3/29 (10.3) | 25/111 (22.5) | 5/16 (31.3) | 0.20 |
| Maternal diabetes, no (%) | 2 /31 (6.5) | 10/111 (9.0) | 1/16 (6.3) | 1.0 |
| Hippocampal volumes at early‐in‐life | n = 28 | n = 96 | n = 15 | – |
| Post‐menstrual age at scan (weeks), median (IQR) | 32.4 (31.4–33.9) | 33.0 (31.9–34.4) | 33.0 (31.9–34.7) | 0.23 |
| Mean hippocampal volume anterior (mm3) | 226.5 (192.5–269) | 226.5 (186.5–262.5) | 234.8 (185–298) | 0.95 |
| Mean hippocampal volume posterior (mm3) | 345 (309.5–400) | 367.5 (321.5–424) | 367.5 (314–401.5) | 0.76 |
| Mean hippocampal volume total (mm3) | 582 (525–633) | 592 (528–656) | 598.8 (493.5–686) | 0.91 |
| Hippocampal volumes at term‐equivalent age | n = 28 | n = 96 | n = 15 | – |
| Post‐menstrual age at scan (weeks), median (IQR) | 41.7 (39.1–43.7) | 40.9 (39.4–43.6) | 41.4 (39.3–42.9) | 0.98 |
| Mean hippocampal volume anterior (mm3) | 323.8 (276.8–397.5) | 318.8 (277.3–404.3) | 370.5 (305–436.5) | 0.36 |
| Mean hippocampal volume posterior (mm3) | 562.3 (514.5–608.8) | 583.8 (498.8–642) | 613.5 (524–673.5) | 0.15 |
| Mean hippocampal volume total (mm3) | 875.5 (802.8–996.8) | 917.3 (767.3–1032.3) | 977 (848–1087) | 0.16 |
| 18‐month cognitive outcome | n = 24 | n = 93 | n = 15 | – |
| Bayley‐III Cognitive Composite score, median (IQR) | 90.0 (82.5–97.5) | 95.0 (90.0–100.0) | 105.0 (95.0–115.0) | 0.011* |
Kruskal–Wallis test for continuous variables, Fisher's exact test for categorical variables, and linear nonparametric test for trends for hippocampal volumes.
Abbreviations: BMI, body mass index; IQR, interquartile range.
*
p value <0.05.