OS084. Maternal haemodynamics at 11-13 weeks of gestation and adverse pregnancy outcomes

Introduction: Women who develop adverse pregnancy outcomes are at increased risk of cardiovascular disease. In individuals with cardiovascular disorders there is increased central aortic systolic blood pressure (SBPAo) and arterial stiffness.

Objectives: The hypothesis is that increased SBPAo and arterial stiffness are apparent before the clinical onset of adverse pregnancy outcomes.

Methods: This was a prospective study in singleton pregnancies at 11(+0)-13(+6) weeks' gestation. Pulse wave velocity (PWV), augmentation index (AIx) and SBPAo were measured. At the same visit, we recorded maternal characteristics and medical history and performed combined screening for aneuploidies. We also measured the uterine artery Doppler pulsatility index (PI). The study outcomes included preeclampsia (PE), gestational hypertension (GH), gestational diabetes (GDM), small for gestational age (SGA) and preterm delivery (PTD). The diagnosis of PE and GH was made according to the guidelines of the International Society for the Study of Hypertension in Pregnancy. The neonate was considered SGA if the birth weight was less than the 5th percentile for gestation at delivery. The diagnosis of GDM was made if the fasting plasma glucose level was at least 6 mmol/L or the plasma glucose level 2 h after oral administration of 75 g glucose was 7.8 mmol/L or more (WHO). We compared these parameters in those that developed PE (n=181), GDM (n=105), GH (n=137), SGA (n=337), PTD prior to 37 weeks' gestation (n=354) with unaffected controls (n=6,766). Multiple regression analysis was used to examine which maternal characteristics provided a significant contribution in the prediction of AIx-75, PWV and SBPAo. Each value was expressed as a multiple of the median (MoM) after adjustment for those characteristics. Pearson correlation analysis was used to examine the association between log10AIx-75 MoM, log10PWV MoM, log10 SBPAo MoM, log10uterine artery PI MoM and log10PAPP-A MoM with gestational age at delivery.

Results: In the PE group there was an increase in AIx-75 (1.13, IQR 0.96-1.33 MoM vs 1.00, IQR 0.87-1.16 MoM, p<0.0001), PWV (1.11, IQR 0.97-1.17 MoM vs 1.00, IQR 0.90-1.12 MoM, p<0.0001), and SBPAo (1.09, IQR 1.02-1.20 MoM vs. 1.00, IQR 0.94-1.08 MoM, p<0.0001). In those that subsequently developed GH, compared to unaffected controls, there was no significant difference in the uterine artery PI, PAPP-A or PWV but AIx-75 and SBPAo were increased (p<0.0001). In the GDM group there was an increase in PWV (1.06, IQR 0.96-1.19 MoM vs. 1.00, IQR 0.90-1.13 MoM, p=0.001) and SBPAo (1.03, IQR 0.98-1.14 vs. 1.00, IQR 0.94-1.08, p<0.0001), but no significant difference in the AIx-75 (1.02, IQR 0.89-1.22 MoM vs. 1.00, IQR 0.87-1.17 MoM, p=0.118). Compared to women who had term delivery, women who had iatrogenic PTD had significantly higher AIx-75 (1.08, IQR 0.91-1.27 MoM vs. 1.00, IQR 0.86-1.16 MoM, p<0.001) and SBPAo (1.06 MoM, IQR 0.98-1.15 vs. 1.00, IQR 0.93-1.07, p<0.001).

Conclusion: A high proportion of women who develop PE, GDM or iatrogenic PTD have increased SBPAo and arterial stiffness that is apparent from the first trimester of pregnancy.