Table 1.
Maternal, neonatal and units’ characteristics according to exposure and duration of exposure to opioids with/without midazolam, among survivors at five years.
| Unexposed (n = 1952) | Exposed |
p value | ||
|---|---|---|---|---|
| ≤7 days (n = 762) | >7 days (n = 403) | |||
| Maternal characteristics at birth | ||||
| Maternal age | ||||
| <25 years | 368/1952 (18.8) | 147/762 (19.5) | 70/403 (17.3) | 0.61 |
| 25–34 years | 1157/1952 (59.3) | 460/762 (60.1) | 235/403 (58.3) | |
| ≥35 years | 427/1952 (21.9) | 155/762 (20.4) | 98/403 (24.4) | |
| Birth in France | 1496/1927 (77.7) | 571/754 (75.6) | 283/401 (70.6) | 0.011 |
| Parents’ socio-economic statusa | ||||
| Executive | 364/1843 (19.9) | 181/729 (24.7) | 87/376 (23.0) | 0.33 |
| Intermediate | 390/1843 (21.2) | 145/729 (20.0) | 69/376 (18.3) | |
| Administration | 515/1843 (28.0) | 189/729 (26.1) | 103/376 (28.2) | |
| Service, trade | 271/1843 (14.5) | 101/729 (13.8) | 56/376 (14.7) | |
| Worker, unemployed | 303/1843 (16.4) | 113/729 (15.4) | 61/376 (15.7) | |
| Multiple pregnancy | 628/1952 (32.3) | 249/762 (32.6) | 135/403 (33.0) | 0.97 |
| Cause of preterm birth | ||||
| Preterm labour | 747/1952 (38.1) | 311/762 (40.1) | 159/403 (37.6) | 0.41 |
| Preterm premature rupture of membranes | 490/1952 (24.8) | 157/762 (20.1) | 100/403 (24.6) | |
| Hypertensive disorders or placenta abruption | 441/1952 (22.9) | 185/762 (25.0) | 89/403 (23.4) | |
| Isolated foetal growth restriction | 126/1952 (6.6) | 44/762 (6.0) | 22/403 (6.2) | |
| Other | 148/1952 (7.6) | 65/762 (8.7) | 33/403 (8.2) | |
| Antenatal corticosteroids | 1633/1915 (85.3) | 626/748 (83.5) | 334/399 (84.3) | 0.49 |
| Magnesium sulphate administration | 153/1923 (8.0) | 70/749 (9.4) | 44/397 (11.6) | 0.061 |
| Neonatal characteristics | ||||
| Gestational age (weeks) | ||||
| 24 | 8/1952 (0.3) | 10/762 (1) | 34/403 (7.4) | <0.001 |
| 25 | 41/1952 (1.6) | 47/762 (4.8) | 86/403 (18.6) | |
| 26 | 98/1952 (3.8) | 74/762 (7.5) | 113/403 (24.5) | |
| 27 | 148/1952 (7.7) | 92/762 (12.6) | 70/403 (20.4) | |
| 28 | 233/1952 (12.2) | 120/762 (16.5) | 39/403 (11.4) | |
| 29 | 311/1952 (16.2) | 133/762 (18.3) | 25/403 (7.3) | |
| 30 | 466/1952 (24.3) | 143/762 (19.6) | 18/403 (5.2) | |
| 31 | 647/1952 (33.8) | 143/762 (19.6) | 18/403 (5.2) | |
| Sex, male | 986/1952 (50.6) | 399/762 (52.5) | 213/403 (53.0) | 0.52 |
| Small-for-GAb | 701/1952 (36.3) | 244/762 (32.8) | 150/403 (39.5) | 0.063 |
| Apgar at 5 min < 7 | 221/1873 (11.7) | 159/728 (21.7) | 106/357 (29.1) | <0.001 |
| Neonatal morbidities, at least one | 399/1868 (20.7) | 255/723 (33.7) | 292/386 (74.9) | <0.001 |
| Severe cerebral abnormalities | 62/1924 (3.2) | 52/753 (6.7) | 49/402 (12.1) | <0.001 |
| Necrotizing enterocolitis | 35/1932 (1.8) | 31/752 (4.0) | 43/402 (11.4) | <0.001 |
| median [IQR] age necrotizing enterocolitis | 21 [12–32] | 28 [21–37] | 23 [17–45] | |
| Severe bronchopulmonary dysplasia | 61/1914 (3.0) | 42/735 (5.3) | 135/381 (35.0) | <0.001 |
| Severe retinopathy of prematurity | 6/1936 (0.3) | 4/756 (0.4) | 29/400 (6.5) | <0.001 |
| Late onset sepsis | 288/1938 (14.4) | 182/750 (23.0) | 191/390 (47.6) | <0.001 |
| Median [IQR] age late onset sepsis | 12 [8–19] | 14 [10–23] | 12 [8–23] | |
| Units’ characteristics | ||||
| Birth in level 3c | 1697/1952 (86.8) | 645/762 (84.4) | 353/403 (87.9) | 0.44 |
| Neonatal unit volume activityd | ||||
| <55 | 768/1952 (39.5) | 249/762 (33.0) | 121/403 (30.2) | <0.001 |
| [55–70] | 399/1952 (20.4) | 164/762 (21.8) | 114/403 (28.4) | |
| [70–90] | 305/1952 (15.8) | 144/762 (18.5) | 70/403 (17.9) | |
| ≥90 | 480/1952 (24.3) | 205/762 (26.7) | 98/403 (23.5) | |
Data are No./total (%), unless otherwise indicated. Denominators vary according to the number of missing data for each variable. Percentages are weighted to consider the differences in survey design between gestational age groups, resulting in numbers different from No./total calculation.
GA = gestational age.
Defined as the highest occupational status between occupations of the mother and the father, or mother only if living alone.
Small-for-GA was defined as birth weight less than the 10th percentile for GA and sex based on French intrauterine “EPOPé” growth curves.22
Maternity wards were classified as level 3 when associated with a neonatal intensive care unit (NICU).
Number of neonates born before 32 GA admitted in 2011, obtained from the national hospital discharge database.