OC25.03: Fetal‐placental Doppler indices are associated with maternal cardiovascular function: a three‐centre study using different techniques

We aim to assess the association between maternal cardiac output (CO) and peripheral vascular resistance (PVR) with maternal-fetal Doppler in relation to presence of pre-eclampsia (PE), small for gestational age (SGA) or fetal growth restriction (FGR) using three different devices once normalised for gestational age. This is a prospective study in three European Centres (London, Hasselt and Rome) on women ≥ 24 weeks with healthy pregnancies or affected by PE, SGA/FGR or both. CO and PVR were assessed using non-invasive devices based on inert gas rebreathing, continuous Doppler or impedance cardiography. CV parameters were normalised using Z-scores by comparing measurements from each technique with those of normal pregnancies assessed with the same technique. Associations between CO/PVR and umbilical artery (UmA), middle cerebral artery (MCA) Z scores and uterine artery (UtA) pulsatility index (PI) were calculated with polynomial regression analysis. We included 233 participants, 81 with healthy pregnancies, 47 with PE, 65 with SGA/FGR and 40 with PE+SGA/FGR. Compared to controls, CO was lower in the SGA/FGR and PE+SGA/FGR groups and PVR was increased in all pathological groups. Standing CO was inversely related with UmA PI (R2 0.036, p = 0.026) and directly with MCA PI (R2 0.052, p = 0.029). Lying and standing PVR were directly associated with UmA PI (R2 0.06, p = 0.001 and R2 0.082, p < 0.001, respectively) and UtA PI (R2 0.049, p = 0.009 and R2 0.054, p = 0.011, respectively), and inversely with MCA PI (R2 0.062, p = 0.016). Lower CO and increased PVR are associated with increasing UtA and UmA PI and decreasing MCA PI. Importantly, these results are generalisable to different centres using techniques for CV assessment. This further reaffirms the recently reported link between maternal cardiovascular function and fetal circulation. In addition, we find that cerebral Doppler is associated with low maternal CO indicating uteroplacental blood flow has a role in fetal circulatory changes.