Is spontaneous preterm delivery associated with impaired arterial stiffness at 6 months postpartum?

Background

Spontaneous preterm delivery (sPTD) is associated with increased risk of cardiovascular disease (CVD), but the mechanistic pathways are not understood.

Objectives

Assess arterial wave reflection and stiffness over time in women with sPTD compared to term delivery.

Methods

A prospective study comparing women with sPTD (gestation age [GA] ≤ 34 weeks) to matched controls (GA ≥ 39 weeks). Data collected at 24–72 hours (n = 40) and 6 months postpartum (n = 33) compared arterial wave reflection and stiffness by heart rate corrected augmentation index (AIx75), central pulse pressure (CPP), and pulse wave velocity (PWV).

Results

Mean GA for sPTD and controls were 30.8 weeks and 39.6 weeks, respectively. Mean maternal age for sPTD was 33 ± 6 years, controls was 32 ± 6 years. Change in vascular function among controls demonstrated significantly lower AIx75 at 6 months postpartum compared to 24–72-hour postpartum [Δ: -14.10, 95 % CI: -21.41- (-6.78), p = 0.001]. There was no change in AIx75 among sPTD cohort at 6 months postpartum (5.15, 95 % CI: -0.99 -11.30, p = 0.118). No significant differences in AIx75 at 6 months postpartum were seen between sPTD and controls (26.27 ± 9.79 vs. 26.94 ± 12.95,).

Conclusions

Women with sPTD had no significant change in AIx75 while term delivery demonstrated significant decreases at 6 months postpartum. This may contribute to mechanistic pathway and future CVD risk understanding for women with sPTD. Further research is warranted to assess if the physiology of full-term pregnancy is beneficial in augmenting vascular function, demonstrating that the timing of delivery is not a confounding variable.