Related Experiment Video
Updated: Jun 10, 2026

Assessment of Maternal Vascular Remodeling During Pregnancy in the Mouse Uterus
Published on: December 5, 2015
Relation between maternal angiogenic factors and utero-placental resistance in normal first- and second-trimester
Katrin Petzold1, Alexander Jank, Renaldo Faber
1Department of Obstetrics, University Hospital of Leipzig, Leipzig, Germany.
Objective:
Soluble endoglin (sEng) is a novel antiangiogenic protein and elevated sEng concentrations in maternal circulation are closely related to preeclampsia and HELLP syndrome. As the perfusion of the uterine arteries as well as the dynamics of angiogenic factors between first and second trimester have prognostic value regarding pregnancy outcome, it was the aim of this study to investigate the relation between maternal angiogenic factors and uterine Doppler parameters.
Study Design:
The longitudinal study includes 50 normal pregnancies. Pulsatility index (PI) of the uterine arteries was detected by Doppler ultrasound in first and second trimester. In parallel, maternal sEng and soluble fms-like tyrosine kinase 1 (sFlt1) concentration was measured using ELISA.
Results:
In the first trimester, the sEng concentrations were 4.92 ± 1.36 ng/mL and the uterine PI was 1.14 ± 0.28. In the second trimester, the maternal sEng concentration decreased significantly to 3.99 ± 0.63 ng/mL (p < 0.05) which was associated by a decrease of the uterine PI to 0.78 ± 0.15 (p < 0.001). Soluble fms-like tyrosine kinase 1 concentrations did not differ significantly between first and second trimester (423 ± 333 vs. 444 ± 291 pg/mL). There was a significant negative correlation between sEng and uterine resistance in the second trimester (r = -0.416; p < 0.001).
Conclusions:
In normal pregnancy, parallel to the fall of utero-placental resistance, there is a physiological decline of the maternal sEng concentration between first and second trimester. In second trimester, there is a negative correlation between sEng and uterine Doppler parameters.
Related Concept Videos
Development of Blood Vessels
The initial formation of this system is facilitated by the small amount of yolk present in the ovum and yolk sac. Blood vessels originate from...
Vascular Resistance
The primary determinants of vascular resistance are vessel diameter, blood viscosity, and vessel length. Among these, vessel diameter plays the most significant role due to the fourth power relationship described by...
Fetal Circulation
Two umbilical arteries transport blood from the fetus to the placenta. At the placenta, the blood absorbs oxygen and nutrients while simultaneously eliminating waste products. This oxygen-enriched and nutrient-rich blood then returns to the fetus through one...
Regulation of Angiogenesis and Blood Supply
Mechanism of Angiogenesis
Teratogenicity

