Ultrasound markers of the genetic pathology and early hemodynamic changes in human embryo

Tsyvian P.B., Kovalev V.V., Kosovtsova N.V.

Abstract.

First trimester nuchal translucency (NT) and ductus venosus reverse blood flow (DVRBF) are used as ultrasound markers (UM) to determine the risk of fetal aneuploidy, heart defects and subsequent maternal preeclampsia. One pathophysiological explanation for these UM, encompassing both normal and pathological outcomes, is the development of transient heart failure due to increased vascular resistance (afterload). Left ventricular isovolumic relaxation time (LV IRT) was demonstrated as sensitive index of afterload increase in the second and third trimester fetus. The objective of study was to determine LV IRT in normally developing embryos and embryos with early UM of chromosomal and cardiac abnormalities and to test the hypothesis of embryonic hypertension as a cause of transient heart failure.
An ultrasound study in 122 normally developing and 27 human embryos with increased NT (>3mm) and DVRBF at gestational ages 11-14 weeks was perfomed. Mean LV IRT (41±3 ms) was 36.6 percent longer in embryos with UM as compared to the normal subset (30±2 ms) (p<0.001).
Considerable reduction in vascular endothelial growth factors (VEGF) synthesis was demonstrated in embryos with UM of chromosomal, cardiac abnormalities and subsequent development of maternal preeclampsia. We speculate that the disturbances in VEGF synthesis may cause some delay in the development of the vascular bed in comparison with heart development and a transitory increase in afterload in the 11–14 weeks embryo. Our observations support the hypothesis that transient heart failure due to increased afterload may be one of the causes of NT and DVRBF in embryo.

Keywords:

intrauterine hypertension, isovolumic relaxation

Autors
Tsyvian Pavel B.
The State Budget Educational Establishment of Higher Professional Education The Ural State Medical Academy Ministry of Social Development and Health Care in Russia, Department of physiology
Russia, Ekaterinburg of street of Repina, 3
Ural Research Institute of Maternity and Child Care
Ekaterinburg, Russia, Repina str.,1
е-mail: tsyvian@hotbox.ru

Kovalev Vladislav V.
Ural Research Institute of Maternity and Child Care
Ekaterinburg, Russia, Repina str.,1
е-mail: omm@k66.ru

Kosovtsova Natalya V.
Ural Research Institute of Maternity and Child Care
Ekaterinburg, Russia, Repina str.,1
е-mail: omm@k66.ru