Table 3.

Incidences preterm birth stratified by singletons and multiples

	Cohort 2020		Cohort 2015–2018
	N	‰	N	‰	OR	95%CI
Singletons	N = 26,504		N = 106,468
Total PTB < 32 weeks	162	6.1	691	6.5	0.94	0.79–1.12
Spontaneous PTB < 32 weeks	107	4.0	380	3.6	1.13	0.91–1.40
Iatrogenic PTB < 32 weeks	55	2.1	311	2.9	0.71	0.53–0.95
Total PTB < 28 weeks	58	2.2	232	2.2	1.01	0.75–1.34
Spontaneous PTB < 28 weeks	46	1.7	141	1.3	1.31	0.94–1.83
Iatrogenic PTB < 28 weeks	12	0.5	91	0.9	0.53	0.29–0.97
Multiples	N = 420		N = 1713
Total PTB < 32 weeks	38	90.5	131	76.5	1.20	0.82–1.75
Spontaneous PTB < 32 weeks	34	81.0	92	53.7	1.55	1.03–2.36
Iatrogenic PTB < 32 weeks	4	9.5	39	22.8	0.41	0.15–1.16
Total PTB < 28 weeks	18	42.9	31	18.1	2.43	1.35–4.39
Spontaneous PTB < 28 weeks	17	40.5	24	14.0	2.97	1.58–5.58
Iatrogenic PTB < 28 weeks	1	2.4	7	4.1	0.58	0.07–4.74

OR odds ratio, CI confidence interval, PTB preterm birth