Maternal hemodynamics at 11-13 weeks of gestation and preterm birth

Women who experience preterm birth (PTB) are at increased risk of cardiovascular morbidity and mortality in the subsequent decades. Individuals with cardiovascular disorders have increased central aortic systolic blood pressure (SBP(Ao)) and arterial stiffness, assessed by pulse wave velocity (PWV) and augmentation index (AIx). The aim of this screening study was to evaluate SBP(Ao), PWV and AIx at 11-13 weeks' gestation in women who delivered preterm.

This was a prospective study in singleton pregnancies at 11 + 0 to 13 + 6 weeks' gestation. Maternal history and characteristics were recorded, and PWV, AIx and SBP(Ao) were measured. We compared these parameters in women who had spontaneous (n = 244) or iatrogenic (n = 110) PTB before 37 weeks' gestation and before 34 weeks with those in women who had term delivery (n = 7489).

Compared with women who had term delivery, women who had iatrogenic PTB had significantly higher AIx (1.08 (interquartile range (IQR), 0.91-1.27) multiples of the median (MoM), vs. 1.00 (IQR, 0.86-1.16) MoM) and SBP(Ao) (1.06 (IQR, 0.98-1.15) MoM vs. 1.00 (IQR, 0.93-1.07) MoM). However, there was no significant difference in AIx, PWV or SBP(Ao) between those who had spontaneous PTB and those who had term delivery. These findings were similar for those who had PTB at < 34 and < 37 weeks' gestation.

Women who had iatrogenic PTB, but not those who had spontaneous PTB, have increased SBP(Ao) and arterial stiffness that is apparent from as early as the first trimester of pregnancy.