Table 3.

Multivariate hazard ratios (95% confidence intervals, CI) for cardiovascular death by preterm status of first and second deliveries, Norwegian Medical Birth Registry.

First birth	Second birth	CVD deaths	Women	HR1	95% CI
Preterm	None	108	7786	4.2	3.4 to 5.1
Preterm	Preterm	41	4819	3.3	2.4 to 4.5
Preterm	Term	98	25393	1.5	1.2 to 1.8
Term	None	621	96919	2.0	1.8 to 2.3
Term	Preterm	87	18038	1.8	1.4 to 2.2
Term	Term	1234	488407	1.0	reference

¹Adjusted for maternal age at delivery, year of delivery, and maternal education (less than high school, completed high school, university)