Table 3

Live-birth pregnancies and risk (HR and 95% CI) of CVD by reproductive interval for women in the Danish National Birth Cohort

Live-birth cycleCasesPerson-yearsModel 1*Model 2†Model 3‡Model 3‡ - stratified by pre-pregnancy BMI
UW/normalOW/OB
CVD risk in each live-birth cycle
 Overall1147688 411n=44 552n=44 552n=40 177; cases=1029n=29 762; cases=705n=10 415; cases=324
 LBC 1412240 1131.13 (0.98 to 1.29)1.12 (0.98 to 1.28)1.08 (0.94 to 1.24)1.14 (0.96 to 1.34)0.98 (0.77 to 1.25)
 LBC 2580346 4611 (reference)1 (reference)1 (reference)1 (reference)1 (reference)
 LBC 313592 6280.85 (0.70 to 1.03)0.84 (0.69 to 1.01)0.85 (0.70 to 1.04)0.91 (0.72 to 1.14)0.75 (0.51 to 1.08)
 ≥LBC 42092091.26 (0.81 to 1.97)1.20 (0.77 to 1.88)1.31 (0.84 to 2.05)1.17 (0.65 to 2.07)1.60 (0.78 to 3.25)
CVD risk during live-birth pregnancies
 Overall14681 050n=44 552n=44 552n=40 177; cases=131n=29 762; cases=97n=10 415; cases=34
 LBP 16939 1061.20 (0.82 to 1.78)1.23 (0.83 to 1.82)1.15 (0.76 to 1.74)1.26 (0.78 to 2.03)0.90 (0.42 to 1.90)
 LBP 25131 5031 (reference)1 (reference)1 (reference)1 (reference)1 (reference)
 LBP 32293521.21 (0.72 to 2.02)1.12 (0.72 to 2.01)1.23 (0.72 to 2.08)1.40 (0.77 to 2.56)0.82 (0.27 to 2.50)
 ≥LBP 4410891.60 (0.57 to 4.50)1.16 (0.36 to 3.81)1.25 (0.38 to 4.12)1.67 (0.49 to 5.63).
CVD risk in the inter-live-birth pregnancy intervals
 Overall537547 365n=44 549n=44 549n=40 174; cases=488n=29 760; cases=326n=10 414; cases=162
 Inter-LBP 1213198 4580.89 (0.74 to 1.08)0.89 (0.73 to 1.07)0.90 (0.74 to 1.10)0.89 (0.70 to 1.13)0.95 (0.68 to 1.32)
 Inter-LBP 2270213 8661 (reference)1 (reference)1 (reference)1 (reference)1 (reference)
 Inter-LBP 34841 9270.89 (0.65 to 1.21)0.88 (0.64 to 1.19)0.90 (0.65 to 1.24)0.84 (0.56 to 1.25)1.06 (0.62 to 1.83)
 ≥Inter LBP 4631151.39 (0.62 to 3.12)1.35 (0.60 to 3.03)1.47 (0.65 to 3.31)0.74 (0.18 to 2.97)2.93 (1.06 to 8.12)
  • *Age as underlying time scale, adjusted for previous CVD diagnosis in an inter-LBP interval for analysis of LBP intervals or previous CVD diagnosis in a LBP interval for analysis of inter-LBP intervals

  • †Adjusted for * and for induced abortions, spontaneous abortions and stillbirths (time-dependent variables)

  • ‡Adjusted for † and for smoking status (ever/never), socio-occupational status, alcohol intake, exercise level and pre-pregnancy body mass index (underweight, normal-weight, overweight and obese)

  • BMI, body mass index; CVD, cardiovascular disease;inter-LBP, inter-live-birth pregnancy; LBC, live-birth cycle; LBP, live-birth pregnancy; OB, obese; OW, overweight; UW, underweight.