Preterm delivery is a maternal risk factor of CVD

Main results

• First pregnancy: 2.1% very preterm, 6.7% moderately preterm and 91.2% at term.
• Women who delivered moderately or very preterm were slightly more like to have a BMI ≥30 kg/m2, pregnancy hypertension and hypercholesterolemia and a family history of CVD. Furthermore, women who delivered very preterm were more likely to be current smokers, experience a stillbirth in first pregnancy and have higher final parity.
• 949 CVD events occurred; 584 definite and 365 probable.
• After adjustment for confounding lifestyle and CVD risk factors, women who had a preterm first birth had an increased rate of CVD (HR 1.42, 95% CI 1.16-1.72).
• When split into 2 categories, the HRs for moderate preterm and very preterm were 1.22 (95% CI 0.96-1.54) and 2.01 (95% CI 1.47-2.75), respectively (trend P<0.0001).
• When analysing stroke and MI separately, results were slightly stronger for MI.
• Increased rate of CVD was present in very preterm live birth (HR 1.98, 95% CI 1.27-3.08) as well as very preterm stillbirth (HR 2.07, 95% CI 1.35-3.18).
• Increased rate of CVD was present in normotensive preterm first pregnancy (HR 1.35, 95% CI 1.06-1.72) but higher in those with both preterm delivery and HDP in first pregnancy (HR 1.66, 95% CI 1.02-2.70).
• Rate was non-significantly higher in normotensive moderate preterm (HR 1.12, 95% CI 0.83-1.52) than in normotensive very preterm individuals (HR 2.01, 95% CI 1.38-2.93).
• Women with a preterm first birth and at least 1 later preterm birth had the largest fully adjusted HR (1.65, 95% CI 1.20-2.28).
• Women with only 1 child (either preterm or term) had an increased rate of CVD compared to women with at least 2 children at term.
• Increased CVD risk was applicable to both women with preterm delivery in the first pregnancy and later preterm deliveries.
• Regarding prepregnancy lifestyle, only chronic hypertension before first pregnancy appeared to be a confounder; HR moderate preterm vs. term were 0.21 (95% CI 0.03-1.52) for with and 1.30 (95% CI 1.02-1.64) for without prepregnancy chronic hypertension and HR very preterm with term were 0.57 (95% CI 0.08-4.14) for with and 2.12 (95% CI 1.54-2.92) for without prepregnancy chronic hypertension.
• 12.8% (95% CI 7.1-21.9) of the association between preterm delivery and CVD was related to postpartum development of chronic hypertension, T2DM, hypercholesterolemia or changes in BMI and was attenuated (5.9%, 95% CI 8.7-27.3) when breastfeeding was also included.

Conclusion

References

Find this publication online at Circulation