Objective: To develop normal ranges of endothelial function in normal human pregnancy to use as a screening test for preeclampsia.
Methods: 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.
Results: FMD increased non-significantly in pregnancy until 32 weeks, when it decreased significantly at 36+ weeks (n = 47).
Conclusion: 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.