Guedes-Martins, L.Gaio, R.Saraiva, J.Cerdeira, S.Matos, L.Silva, E.Macedo, F.Almeida, H.2016-07-192016-07-192015PLoS One. 2015 Mar 5;10(3):e01191031932-6203http://hdl.handle.net/10400.16/1956Cyclic endometrial neoangiogenesis contributes to changes in local vascular patterns and is amenable to non-invasive assessment with Doppler sonography. We hypothesize that the uterine artery (UtA) impedance, measured by its pulsatility index (PI), exhibits a regular pattern during the normal menstrual cycle. Therefore, the main study objective was to derive normative new day-cycle-based reference ranges for the UtA-PI during the entire cycle from days 1 to 34 according to the isolated time effect and potential confounders such as age and parity.engAdolescentAdultCross-Sectional StudiesFemaleHumansMiddle AgedUterine ArteryYoung AdultMenstrual Cyclejournal article10.1371/journal.pone.0119103