Singleton
|
35 (71)
|
71 (79)
|
0.32
|
26 (77)
|
50 (81)
|
0.63
|
Vaginal delivery
|
29/49 (59)
|
50/89 (56)
|
0.73
|
16 (47)
|
31 (51)
|
0.72
|
Male
|
32 (65)
|
59 (66)
|
0.97
|
25 (74)
|
45 (73)
|
0.92
|
White
|
21/44 (48)
|
52/87 (60)
|
0.56
|
15/31 (48)
|
33/59 (56)
|
0.86
|
Black
|
7 (16)
|
13 (15)
|
1.00
|
5 (16)
|
10 (17.0)
|
0.99
|
Hispanic
|
4 (9)
|
5 (6)
|
0.92
|
3 (10)
|
5 (8)
|
0.97
|
Other
|
12 (27)
|
17 (19)
|
0.60
|
8 (26)
|
11 (19)
|
0.63
|
Mean birth weight (g)
|
748 ± 159
|
755 ± 146
|
0.80
|
790 ± 162
|
792 ± 151
|
0.93
|
Mean head circumference at birth (cm)
|
22.9 ± 1.6
|
23.3 ± 1.9
|
0.33
|
23.5 ± 1.6
|
23.5 ± 1.3
|
0.93
|
Mean length at birth (cm)
|
32.1 ± 2.2
|
32.9 ± 2.7
|
0.14
|
32.5 ± 2.3
|
33.0 ± 2.4
|
0.37
|
Median gestational age (weeks)
|
25 (23–30)
|
25.5 (23–30)
|
0.73
|
25.5 (23–30)
|
25.5 (23–30)
|
0.70
|
Respiratory distress syndrome
|
41 (84)
|
83 (92)
|
0.35
|
26 (77)
|
56 (90)
|
0.23
|
Gastrointestinal disorders other than NECa
|
2 (4)
|
1 (1)
|
0.23
|
2 (6)
|
1 (2)
|
0.26
|
NEC
|
12 (24)
|
8 (9)
|
0.008
|
12 (35)
|
6 (10)
|
0.01
|
PDA or other congenital heart diseaseb
|
37 (76)
|
63 (70)
|
0.67
|
27 (80)
|
42 (68)
|
0.25
|
Intrauterine growth retardation
|
3 (6)
|
4 (4)
|
1.00
|
3 (9)
|
4 (6)
|
1.00
|
Median age at enrolment (days)
|
14 (1–84)
|
14 (0–84)
|
1.00
|
20 (9–84)
|
16 (3–84)
|
0.89
|
Median time from admission to death or discharge) (days)
|
71 (3–492)
|
89 (1–165)
|
0.54
|
91 (3–492)
|
79 (1–142)
|
0.09
|