TABLE 3.

Sensitivity analysis for pregnancy characteristics.

	Uterine scar (−)	Myoma (−)	Uterine scar/myoma (−)
	aOR (95% CI)	aOR (95% CI)	aOR (95% CI)
Placenta previa
No	1.00 (reference)	1.00 (reference)	1.00 (reference)
Yes	12.4 (9.75–15.7)	5.57 (4.57–6.78)	15.4 (11.7–20.4)
Placenta accreta spectrum
No	1.00 (reference)	1.00 (reference)	1.00 (reference)
Yes	13.9 (4.97–38.7)	2.70 (1.63–4.49)	13.2 (4.62–37.8)
Placenta abruption
No	1.00 (reference)	1.00 (reference)	1.00 (reference)
Yes	4.96 (3.84–6.41)	3.66 (2.89–4.65)	5.83 (4.34–7.82)
Pre‐eclampsia
No	1.00 (reference)	1.00 (reference)	1.00 (reference)
Yes	1.37 (1.20–1.56)	1.39 (1.23–1.57)	1.61 (1.38–1.87)
PROM
No	1.00 (reference)	1.00 (reference)	1.00 (reference)
Preterm	1.66 (1.39–1.99)	1.57 (1.32–1.88)	1.80 (1.46–2.22)
Term	1.20 (1.04–1.40)	1.17 (1.02–1.35)	1.28 (1.09–1.50)
Multifetal gestation
No	1.00 (reference)	1.00 (reference)	1.00 (reference)
Yes	2.13 (1.73–2.62)	1.29 (1.07–1.57)	1.91 (1.49–2.43)
Large for gestational age
No	1.00 (reference)	1.00 (reference)	1.00 (reference)
Yes	3.16 (2.68–3.74)	2.48 (2.13–2.88)	3.18 (2.65–3.82)
Fetal growth restriction
No	1.00 (reference)	1.00 (reference)	1.00 (reference)
Yes	1.69 (1.42–2.01)	1.61 (1.37–1.90)	2.09 (1.72–2.53)
Breech presentation
No	1.00 (reference)	1.00 (reference)	1.00 (reference)
Yes	2.29 (2.01–2.62)	1.89 (1.66–2.14)	2.87 (2.46–3.35)

Note: Independent characteristics in the whole cohort analysis were tested in three restricted cohorts: no uterine scar, no uterine myoma or neither of the two diagnoses.

Abbreviations: aOR, adjusted‐odds ratio; CI, confidence interval; PROM, premature rupture of membranes.