Table 3.

Pregnancy complications (preeclampsia, preterm birth, and/or small for gestational age) in first or last pregnancy by the mother’s total number of births and the relation to maternal CVD death stratified by mothers’ birth year. First births included up to 2013 and mothers followed through 2020 (n = 1,011,767)

Reproduction	Total N	CVD deaths a : N (row %)	Crude HR (95% CI)	Adjusted HR (95%CI) b
Mothers’ birth year 1922–1948: N = 118 107
One child only
No complication	18 833 (16.0)	334 (1.77)	1.67 (1.45–1.92)	1.61 (1.40–1.85)
Complication	7136 (6.0)	209 (2.93)	2.84 (2.42–3.35)	2.54 (2.15–2.99)
Two births
No complications	45 062 (38.2)	487 (1.08)	Reference	Reference
Complication only first	9599 (8.1)	147 (1.53)	1.43 (1.19–1.71)	1.37 (1.14–1.65)
Complication only last	4,989 (4.2)	97 (1.94)	1.85 (1.49–2.30)	1.74 (1.40–2.17)
Three-eight births
No complications	24 214 (20.5)	227 (0.94)	0.94 (0.80–1.10)	0.93 (0.80–1.09)
Complication only first	5075 (4.3)	76 (1.50)	1.50 (1.18–1.91)	1.44 (1.13–1.83)
Complication only last	3199 (2.7)	63 (1.97)	2.08 (1.60–2.70)	1.85 (1.43–2.41)
Mothers’ birth year 1949–1974: N = 577 472
One child only
No complication	78 035 (13.5)	474 (0.61)	1.45 (1.29–1.62)	1.45 (1.29–1.63)
Complication	25 986 (4.5)	296 (1.14)	2.69 (2.35–3.08)	2.57 (2.25–2.94)
Two births
No complications	218 727 (37.9)	778 (0.36)	Reference	Reference
Complication only first	42 506 (7.4)	234 (0.55)	1.49 (1.29–1.72)	1.42 (1.23–1.65)
Complication only last	22 697 (3.9)	167 (0.74)	1.95 (1.65–2.30)	1.83 (1.55–2.17)
Three-eight births
No complications	144 384 (25.0)	437 (0.30)	1.20 (1.06–1.35)	1.18 (1.05–1.33)
Complication only first	26 995 (4.7)	127 (0.47)	1.73 (1.43–2.08)	1.64 (1.35–1.97)
Complication only last	18 142 (3.1)	140 (0.77)	2.92 (2.44–3.49)	2.62 (2.18–3.14)

Note: ^a death up to 69 years, ^b adjusted for maternal education