Table 4 Participant demographics for control and progesterone groups

n/N (%)

42/67 (63%)

25/67(37%)

67/67 (100%)

 Mean ± SD (range)

32 ± 5.5 (21–40)

32 ± 3.9 (22–38)

32 ± 5.0 (21–40)

 Mean ± SD (range)

24.7 ± 5.3 (19–48)

25.2 ± 4.7 (18.4–35)

24.9 ± 5.0 (18.4–48)

 Caucasian

32/42 (76%)

18/25 (72%)

50/67 (75%)

 Asian

4/42 (10%)

3/25 (12%)

7/67 (10%)

 Black

6/42 (14%)

4/25 (16%)

10/67 (15%)

Smoker n/N (%)

2/42 (5%)

0/25 (0%)

2/67 (3%)

Screening for progesterone

 GA (weeks), median, range

15⁺⁰ (12⁺¹–18⁺²)

15⁺⁶ (12⁺⁰–18⁺⁶)

15⁺³ (12⁺⁰–18⁺⁶)

 CL (mm), median, range

32 (26–43)

22 (13–25)

(13–43)

 Early PTB, <34⁺⁰ weeks

1/42 (2%)

4/25 (16%)

5/67 (7%)

 Late PTB, 34⁺⁰ to <37⁺⁰ weeks

1/42 (2%)

4/25 (16%)

5/67 (7%)

 Term, ≥37⁺⁰ weeks

40/42 (95%)

17/25 (68%)

57/67 (85%)