A longitudinal study using ultrasound to assess flow-mediated dilatation in normal human pregnancy.

<bold>Objective: </bold>To develop normal ranges of endothelial function in normal human pregnancy to use as a screening test for preeclampsia. <bold>Methods: </bold>In this longitudinal study, women were studied five times during pregnancy and once postpartum using flow-mediated dilatation (FMD). FMD is a noninvasive ultrasound technique used to assess endothelial function. Healthy nonpregnant women were controls. <bold>Results: </bold>FMD increased non-significantly in pregnancy until 32 weeks, when it decreased significantly at 36+ weeks (n = 47). <bold>Conclusion: </bold>The fall in FMD in the third trimester has not been previously reported. This indicates the importance of gestational age when assessing FMD as a screening test for preeclampsia. [ABSTRACT FROM AUTHOR]