Table 1 Neonatal characteristics of the total study population and for each five-year birth interval
From: Increased risk of pulmonary hypertension following premature birth
Variable | Status | 1973–1977 | 1978–1982 | 1983–1987 | 1988–1992 | 1993–1997 | 1998–2002 | 2003–2007 | 2008–2010 | Total (N) | % |
|---|---|---|---|---|---|---|---|---|---|---|---|
Total number of cases | Case | 21 | 18 | 16 | 4 | 14 | 12 | 17 | 26 | 128 | |
Total number of controls | Control | 126 | 108 | 96 | 24 | 84 | 72 | 102 | 156 | 768 | |
Maternal age (years) | Case | 25,0 | 27,1 | 28,8 | 24,8 | 29,5 | 31,9 | 31,5 | 32,3 | 29,3 | |
Control | 24,4 | 27,5 | 28,9 | 26,3 | 29,4 | 29,0 | 30,8 | 29,9 | 28,7 | ||
p-value | 0.2306 | 0.7756 | 0.9704 | 0.4878 | 0.9463 | 0.0567 | 0.611 | 0.0251 | 0.2905 | ||
Maternal hypertension | Case | 2 | 4 | 0 | 0 | 3 | 1 | 2 | 3 | 15 | 12% |
Control | 11 | 8 | 5 | 1 | 1 | 1 | 3 | 0 | 37 | 5% | |
p-value | 1 | 0.0696 | 1 | 1 | 0.0087 | 0.2669 | 0.144 | 1 | 0.0064 | ||
Maternal smoking | Case | – | 1 | 2 | 0 | 2 | 0 | 1 | 2 | 8 | 6% |
Control | – | 2 | 24 | 5 | 9 | 6 | 11 | 6 | 63 | 8% | |
p-value | – | 1 | 0.5097 | 1 | 0.6324 | 0.58 | 1 | 0.2671 | 0.7108 | ||
Premature birth | Case | 1 | 1 | 0 | 0 | 0 | 2 | 5 | 18 | 27 | 21% |
Control | 4 | 4 | 5 | 4 | 8 | 5 | 2 | 15 | 47 | 6% | |
p-value | 0.2045 | 0.5467 | 0.0860 | 1.0000 | 0.1902 | 0.0044 | 8.82E-05 | < 0.0001 | < 0.0001 | ||
Acute neonatal pulmonary disease | Case | 1 | 1 | 0 | 0 | 2 | 3 | 5 | 15 | 27 | 21% |
Control | 4 | 6 | 4 | 1 | 6 | 6 | 3 | 13 | 43 | 6% | |
p-value | 0.5427 | 1.0000 | 1.0000 | 1.0000 | 0.3200 | 0.1146 | 0.0014 | < 0.0001 | < 0.0001 | ||
Bronchopulmonary dysplasia | Case | 0 | 0 | 0 | 0 | 1 | 1 | 2 | 10 | 14 | 11% |
Control | 2 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 2 | 0% | |
p-value | 1.0000 | 1.0000 | 1.0000 | 1.0000 | 0.1429 | 0.1429 | 0.0194 | < 0.0001 | < 0.0001 | ||
Congenital diaphragmatic hernia | Case | 0 | 0 | 0 | 1 | 3 | 0 | 0 | 2 | 6 | 1% |
Control | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 1 | 0% | |
p-value | 1.0000 | 1.0000 | 1.0000 | 0.1429 | 0.0087 | 1.0000 | 1.0000 | 0.0197 | < 0.0001 | ||
Congenital heart disease | Case | 2 | 3 | 3 | 2 | 2 | 2 | 5 | 4 | 23 | 18% |
Control | 2 | 2 | 0 | 0 | 3 | 1 | 0 | 2 | 10 | 1% | |
p-value | 0.0979 | 0.0207 | 0.0026 | 0.0159 | 0.1476 | 0.0522 | 3.39E-05 | 0.0041 | < 0.0001 | ||
Chronic pulmonary disease | Case | 0 | 0 | 0 | 0 | 1 | 1 | 2 | 11 | 15 | 12% |
Control | 2 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 3 | 0% | |
p-value | 1.0000 | 1.0000 | 1.0000 | 1.0000 | 0.1429 | 0.1429 | 0.0194 | < 0.0001 | < 0.0001 | ||
First-born child | Case | 9 | 8 | 7 | 4 | 8 | 2 | 5 | 10 | 53 | 41% |
Control | 56 | 46 | 43 | 9 | 34 | 23 | 53 | 82 | 316 | 41% | |
p-value | 0.6429 | 0.8001 | 0.1379 | 0.2734 | 0.2494 | 0.1199 | 0.7872 | 0.5252 | 1.000 | ||
Female sex | Case | 15 | 9 | 11 | 3 | 5 | 10 | 6 | 13 | 72 | 56% |
Control | 56 | 46 | 43 | 9 | 34 | 23 | 53 | 82 | 346 | 45% | |
p-value | 0.0324 | 0.6132 | 0.1051 | 0.2850 | 1.0000 | 0.0011 | 0.2950 | 0.8349 | 0.0215 | ||
Chromosomal abnormalities | Case | 1 | 1 | 1 | 1 | 2 | 1 | 3 | 0 | 10 | 8% |
Control | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 0% | |
p-value | 0.1428 | 0.1428 | 0.1428 | 0.1428 | 0.0191 | 0.1428 | 0.0025 | 1.0000 | < 0.0001 |