Table 1 Clinical and demographic characteristics of the study population

Total number

20

15

87

Age (years)

33 (31–34)

34 (30–37)

0.6410

33 (32–34)

0.79

0.9279

 Caucasian

10 (50%)

6 (40%)

38 (44%)

 Black

5 (25%)

3 (20%)

0.6393

20 (23%)

0.8796

0.9207

 Asian

5 (25%)

6 (40%)

29 (33%)

GA first sample (weeks)

28⁺² (28⁺¹–29⁺⁰)

32⁺⁰ (27⁺⁰–34⁺⁰)

0.1871

28⁺¹ (25⁺¹–33⁺⁰)

0.2743

0.4504

GA at MR (weeks)

n/a

34⁺⁴ (31⁺⁰–35⁺²)

27⁺⁰ (24⁺⁶–32⁺⁴)

0.0011

GA at delivery (weeks)

40⁺¹ (39⁺²–41⁺¹)

34⁺⁴ (31⁺⁰–35⁺²)

6.12 × 10^-7

30⁺⁴ (26⁺⁵–34⁺²)

0.0142

<0.0001

 1 min

9 (8–9)*

9 (8–9)*

0.6432

6 (5–9)**

0.0013

<0.0001

 5 min

10 (10–10)*

9 (9–10)*

0.0656

8 (7–9)**

0.0183

<0.0001

BW (g)

3400 (3215–3980)*

2285 (1720–2560)

0.000005

1550 (877.5–2216)

0.0140

<0.0001

Admission to neonatal unit

0 (0%)

3 (20%)

0.069519

59 (68%)

0.00094

<0.0001

 PPROM to delivery (days)

n/a

1 (0–4)

4 (2–9)

0.0212