Table 3

First-born versus second-born multiples: demographics, DR measures and outcomes

All multiplesMonochorionic multiples
First-born multiples
(n=43)
Second-born multiples
(n=43)
Paired
p value*
Adjusted
p value†
First-born multiples
(n=22)
Second-born multiples
(n=22)
Paired
p value*
Adjusted
p value†
Neonatal and maternal demographics
 Gestational age, weeks, median (range)31.0 (24.6–32.9)31.0 (24.6–32.9)N/A30.6 (25.6–32.7)30.6 (25.6–32.7)N/A
 Birth weight, grams, median (range)1550 (600–2300)1438 (610–2560) 0.02 1510 (680–2205)1380 (610–1940) 0.008
 Caesarean section, %88911.086911.0
 Male sex, %49440.841411.0
 Antenatal steroids, %9898N/A9595N/A
Delivery room measures
 1 min Apgar <3, %571.00.8551.00.9
 5 min Apgar <7, %1970.20.12350.20.1
 Delivery room intubation, %991.00.99141.00.4
 Delivery room chest compression, %221.00.9051.0
 Admission temperature, °C, mean (SD)36.9 (0.4)36.9 (0.6)0.40.636.7 (0.5)36.8 (0.4)0.70.8
Respiratory and haematological outcomes
 Surfactant, %23140.20.136180.1 0.02
 Any intubation, %16191.00.723271.00.5
 Pneumothorax, %021.0001.0
 Early (<72 hours) red blood cell transfusion, %521.0551.0
 Any red blood cell transfusion, %14260.10.218360.10.2
 Initial haematocrit (<2 hours), mean (SD)§*51.3 (7.0)49.9 (7.1)0.30.751.5 (7.9)49.9 (7.1)0.30.8
 Haematocrit at 12–24 hours, mean (SD)¶*53.4 (8.4)54.1 (7.3)0.60.452.7 (7.7)56.0 (8.3)0.1 0.02
 Polycythaemia (haematocrit >65%), %0000
 Peak bilirubin, mg/dL, mean (SD)8.8 (2.3)8.6 (2.6)0.50.38.7 (2.3)8.1 (2.6)0.20.5
 Exchange transfusion, %0000
Neonatal mortality and morbidity
 NICU death, %001.0001.0
 Severe intraventricular haemorrhage, %201.0001.0
 Chronic lung disease, %7160.10.19230.20.6
 Late-onset sepsis, %070.3090.5
 Necrotising enterocolitis, %021.0051.0
 Severe retinopathy of prematurity, %270.50.2090.5
 Survival without major morbidity, %9177 0.03 0.191730.10.9
  • Bold values represents significant of p values <0.05.

  • *Wilcoxon signed-rank and McNemar tests were used for continuous and categorical variables, respectively.

  • †Adjusted for birth weight.

  • ‡Insufficient events to run particular model for statistical analysis.

  • §Missing data=6%.

  • ¶Missing data=40%.

  • NICU, neonatal intensive care unit.