AUTHOR=Hitzerd Emilie , Reijnders Igna F. , Mulders Annemarie G. M. G. J. , Koning Anton H. J. , Reiss Irwin K. M. , Danser A. H. Jan , Steegers-Theunissen Régine P. M. , Simons Sinno H. P. , Koster Maria P. H. 

TITLE=Larger First-Trimester Placental Volumetric Parameters Are Associated With Lower Pressure and More Flow-Mediated Vasodilation of the Fetoplacental Vasculature After Delivery

JOURNAL=Frontiers in Physiology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2020.00006

DOI=10.3389/fphys.2020.00006

ISSN=1664-042X

ABSTRACT=<sec><title>Objective</title><p>To explore the correlation between <italic>in vivo</italic> placental volumetric parameters in the first trimester of pregnancy and <italic>ex vivo</italic> parameters of fetoplacental vascular function after delivery.</p></sec><sec><title>Methods</title><p>In ten singleton physiological pregnancies, placental volume (PV) and uteroplacental vascular volume (uPVV) were measured offline in three-dimensional ultrasound volumes at 7, 9, and 11 weeks gestational age (GA) using Virtual Organ Analysis and Virtual Reality. Directly postpartum, term placentas were <italic>ex vivo</italic> dually perfused and pressure in the fetoplacental vasculature was measured to calculate baseline pressure (pressure after a washout period), pressure increase (pressure after a stepwise fetal flow rate increase of 1 mL/min up to 6 mL/min) and flow-mediated vasodilation (FMVD; reduction in inflow hydrostatic pressure on the fetal side at 6 mL/min flow rate). Correlations between <italic>in vivo</italic> and <italic>ex vivo</italic> parameters were assessed by Spearman’s correlation coefficients (R).</p></sec><sec><title>Results</title><p>Throughout the first trimester, PV was negatively correlated with pressure increase (<italic>R</italic><sub>growth</sub> = −0.84) and, at 11 weeks GA, also positively correlated with FMVD (<italic>R</italic> = 0.89). At 7 weeks GA, uPVV and uPVV/PV ratio were negatively correlated with pressure increase (<italic>R</italic> = −0.58 and <italic>R</italic> = −0.81, respectively) and positively correlated with FMVD (<italic>R</italic> = 0.62 and <italic>R</italic> = 0.90, respectively).</p></sec><sec><title>Discussion</title><p>Mainly in the early first trimester, larger placental volumetric parameters are associated with lower pressure and more FMVD in the fetoplacental vasculature after delivery. This may suggest that larger and/or more vascularized placentas in early pregnancy have better adaptive mechanisms and possibly lead to better pregnancy outcomes.</p></sec>