Table 1 Baseline characteristics after 1:1 stratification matching in the HDP and non-HDP groups.

From: Mortality and neurological outcomes in extremely and very preterm infants born to mothers with hypertensive disorders of pregnancy

 

HDP

non-HDP

 

Variables

(n = 4,584)

(n = 4,584)

p-value

Maternal characteristics

   

Maternal age (years)

33.8 ± 5.0

33.0 ± 5.1

 

Category of age

  

1.0

10’s

22 (0.5%)

22 (0.5%)

 

20’s

883 (19.3%)

883 (19.3%)

 

30’s

3,152 (68.8%)

3,152 (68.8%)

 

40’s and over

527 (11.5%)

527 (11.5%)

 

Primiparous

2,632 (57.4%)

2,632 (57.4%)

1.0

Gestational age (weeks)

28.8 ± 2.2

28.7 ± 2.1

 

Category of gestational weeks

  

1.0

22–23 weeks

84 (1.8%)

84 (1.8%)

 

24–27 weeks

1,402 (30.6%)

1,402 (30.6%)

 

28–31 weeks

3,098 (67.6%)

3,098 (67.6%)

 

Caesarean section

4,406 (96.1%)

3,332 (72.7%)

 < 0.01

DM or GDM

190 (4.1%)

133 (2.9%)

 < 0.01

Histological chorioamnionitis

643 (14.0%)

2,043 (44.6%)

 < 0.01

Antenatal corticosteroid

2,460 (53.7%)

2,747 (59.9%)

 < 0.01

PROM

188 (4.1%)

1,997 (43.6%)

 < 0.01

Year of delivery

  

1.0

2003–2008

1,191 (26.0%)

1,191 (26.0%)

 

2009–2015

3,393 (74.0%)

3,393 (74.0%)

 

Neonatal characteristics

   

Male

2,124 (46.3%)

2,467 (53.8%)

 < 0.01

Birth weight (g)

913 ± 291

1,090 ± 280

 < 0.01

Height (cm)

34.0 ± 4.0

35.9 ± 3.6

 < 0.01

SGA

2,477 (54.0%)

772 (16.8%)

 < 0.01

  1. Data are given as mean ± standard deviation for continuous variables and n (%) for categorical variables. HDP, hypertensive disorders of pregnancy; DM, diabetes mellitus; GDM, gestational diabetes mellitus; PROM, premature rupture of membranes; SGA, small for gestational age.