Table 3. Outcomes by Trimester in the Cohort With AC and the Propensity Score–Matched Control Cohort.

Presentation, outcome	Events, No./total No. (%) [95% CI]		Odds ratio (95% CI)a
	Cohort with AC (n = 5759)	Propensity score–matched cohort (n = 23 036)
Trimester 1
Pregnancy loss	629/2518 (24.98) [23.31-26.73]	2066/10 072 (20.51) [19.61-21.45]	1.29 (1.16-1.43)
Preterm delivery	294/1889 (15.56) [13.97-17.30]	668/7556 (8.84) [8.19-9.50]	1.90 (1.64-2.20)
Trimester 2
Pregnancy loss	34/1736 (1.96) [1.38-2.76]	65/6944 (0.94) [0.71-1.18]	2.11 (1.34-3.24)
Preterm delivery	267/1702 (15.69) [14.01-17.52]	706/6808 (10.37) [9.65-11.12]	1.61 (1.38-1.86)
Trimester 3
Pregnancy lossb	1/1505 (0.07) [0.00-0.43]	4/6020 (0.07) [0.02-0.13]	1.00 (0.00-8.01)
Preterm delivery	226/1504 (15.03) [13.28-16.96]	323/6016 (5.37) [4.79-5.97]	3.12 (2.64-3.70)

Abbreviation: AC, acute cholecystitis.

^a Results from the propensity score–matched analysis.

^b Pregnancy loss rates in the third trimester were too low to make a comparison. This is consistent with preexisting obstetric data.¹⁶