P20.03: Relationship between uterine artery pulsatility index and fetal fraction cell‐free DNA in maternal plasma at 11+0 to 13+6 weeks of gestation.

To examine the relationship of uterine artery pulsatility Index (PI) on the fetal fraction (FF) in maternal plasma cell-free (cf) DNA at 11+0-13+6 weeks of gestation and the possible association with other maternal and fetal characteristics. Uterine artery velocity waveforms were evaluated at the time of maternal sampling by Doppler ultrasonography (WS80 Samsung Medical, Seoul, Republic of Korea) from both uterine arteries and the mean PI calculated. FF in maternal plasma cfDNA is affected by maternal weight and uterine artery impedance to flow at 11+0-13+6 weeks of gestation. [Extracted from the article]