# PTB n(%) Term Total OR [95% CI]
In pregnancy 4,787 (7.5) 59,030 63,817 1.33 [1.29, 1.37]
1st trimester 2142 (8.0) 24,736 26,878 1.42 [1.36, 1.48]
2nd trimester 2630 (8.2) 29,286 31,916 1.47 [1.41, 1.53]
1st and 2nd trimester 553 (9.2) 5,442 5,995 1.66 [1.52, 1.81]
No BV &
no medication 125,815 (5.7) 2,061,443 2,187,258