Table 1 Characteristics of the preterm infant cohort used for overall analyses.

Neonate characteristics

Sample size

15

94

Birth weight (g)

938.8 ± 71.5

1187.6 ± 25.0

0.002

Gestational age (weeks)

27.5 ± 0.6

30.2 ± 0.2

 < 0.001

Sex

Male 10 (67%)

Male 30 (32%)

0.013

Female 5 (33%)

Female 64 (68%)

Cumulative NICU O₂ (Days)

46.5 ± 4.0

7.8 ± 1.1

 < 0.001

 Day

0

31

 1–13 days

0

40

 ≥ 14 days

15

22

 Unknown

0

1

Delivery room surfactant

1/13 (8%)

4/87 (5%)

0.644

Infection in NICU

8/14 (57%)

20/93 (22%)

0.006

Maternal characteristics

Maternal ancestry

0.863

 European-Latin

12

69

 Criollos

0

14

 European-other

0

5

 Jewish

1

3

 African Caribbean

0

1

 Asian

0

1

 Native American

1

0

 Arab-Middle Eastern

1

0

 Unknown or refused

0

1

Maternal age (year)

32.2 ± 1.9

34.1 ± 0.7

0.369

Maternal smoking history^a

7/15 (47%)

25/94 (27%)

0.116

Maternal antenatal steroid

15/15 (100%)

83/91 (91%)

0.239

Maternal pre-eclampsia

3/15 (20%)

26/94 (28%)

0.539

Gestational diabetes

0/14 (0%)

1/90 (1%)

0.714

BMI

34.6 ± 3.1

35.6 ± 1.3

1.000

Education^b

10/4/0/1

63/20/5/6

0.916

Alcohol during pregnancy

0/13 (0%)

1/89 (1%)

0.724

Chorioamnionitis

2/15 (13%)

5/94 (5%)

0.246

Fetal complications

 Fetal IUGR

5/13 (39%)

38/89 (43%)

0.778

 Fetal oligohydramnios

3/12 (25%)

11/89 (12%)

0.240