Table 1

Clinical characteristics of the VLBW cohort with gestational age 22+0–31+6 weeks stratified to arterial hypotension (lower BP, minMAP24 lower than the median minMAP24 of gestational age) in the first 24 h of life

Higher BP* (n=2619)Lower BP (n=2288)p Value†
minMAP24 in mm Hg (mean, SD)30.87 (5.1)22.84 (3.9)
Gestational age in weeks (mean, SD)28.02 (2.29)28.10 (2.23)0.213
Birth weight in g (mean, SD)1013 (295)1015 (305)0.692
Gender, male (%)51.851.50.820
Small for gestational age (%)12.412.70.734
Multiples (%)31.434.90.01
Inborn (%)97.697.40.618
Mode of delivery (%)
 Elective caesarean section (%)77.477.4<0.001
 Emergency caesarean section8.411.9
Early-onset sepsis (%)1.51.80.476
Umbilical cord pH (mean, SD)7.32 (0.09)7.31 (0.10)0.73
5 min Apgar score <7 (%)16.020.8<0.001
Mechanical ventilation (%)4861<0.001
  • p Values<0.05 are given in bold.

  • *The number of infants in the higher BP group is higher than the number of infants in the low BP group since higher BP was defined as BP ≥median BP of the according week of gestational age.

  • †Mann–Whitney U test for gestational age, birth weight and umbilical cord pH; χ2 test for all other variables.

  • BP, blood pressure; minMAP24, lowest mean arterial blood pressure during the first 24 h of life; VLBW, very-low birth weight.