Fetal cardiac function at 35-37 weeks' gestation in pregnancies that subsequently develop pre-eclampsia

Objective To compare fetal cardiac morphology and function between pregnancies that subsequently developed pre-eclampsia (PE) and those that remained normotensive. Methods This was a prospective observational study in 1574 pregnancies at 35-37 weeks' gestation, including 76 that subsequently developed PE. We carried out comprehensive assessment of fetal cardiac morphology and function including novel imaging modalities, such as speckle-tracking echocardiography, and measured uterine artery pulsatility index, mean arterial pressure (MAP), serum placental growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFlt-1) and cerebroplacental ratio (CPR). The findings in the group that subsequently developed PE were compared to those in pregnancies that remained normotensive. Results In fetuses of mothers who subsequently developed PE, compared to those from normotensive pregnancies, there was a more globular right ventricle, as shown by reduced right ventricular sphericity index, reduced right ventricular systolic contractility, as shown by reduced global longitudinal strain, and reduced left ventricular diastolic function, as shown by increased E/A ratio. On multivariable regression analysis, these indices demonstrated an association with PE, independent of maternal characteristics and fetal size. In pregnancies that subsequently developed PE, compared to those that remained normotensive, MAP, sFlt-1 and the incidence of low birth weight were higher, whereas serum PlGF, CPR and the interval between assessment and delivery were lower. These findings demonstrate that, in pregnancies that develop PE, there is evidence of impaired placentation, reflected in low PlGF and reduced birth weight, placental ischemia, evidenced by increased sFlt-1 which becomes apparent in the interval of 2-4 weeks preceding the clinical onset of PE, and consequent fetal hypoxia-induced redistribution in the fetal circulation, reflected in the low CPR. Conclusion Although the etiology of the observed fetal cardiac changes in pregnancies that subsequently develop PE remains unclear, it is possible that the reduction in right-heart systolic function is the consequence of high afterload due to increased placental resistance, whilst the early left ventricular diastolic changes could be due to fetal hypoxia-induced redistribution in the fetal circulation. (C) 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Automated summary

In fetuses of mothers who subsequently developed pre-eclampsia, there were notable differences in cardiac morphology and function compared to those from normotensive pregnancies. These differences included a more globular right ventricle, reduced right ventricular systolic contractility, and reduced left ventricular diastolic function. Additionally, other markers such as mean arterial pressure, soluble fms-like tyrosine kinase-1, and serum placental growth factor showed differences between the two groups, indicating possible implications for impaired placentation and fetal hypoxia-induced redistribution in pregnancies that develop pre-eclampsia.