Uterine Artery Pulsatility Index (PI) in Prediction of Pre-eclampsia
There is evidence that in a high proportion of pregnancies destined to develop pre-eclampsia the uterine artery pulsatility index (PI) ) is increased at 11 to 13 weeks1, 2,3.
Protocol For First-Trimester Measurement of The Uterine Artery PI
- The gestational age must be between 11 weeks and 13 weeks and six days.
- A sagittal section of the uterus must be obtained and the cervical canal and internal cervical os identified. Subsequently, the transducer must be gently tilted from side to side and then color flow mapping should be used to identify each uterine artery along the side of the cervix and uterus at the level of the internal os.
- Pulsed wave Doppler should be used with the sampling gate set at 2 mm to cover the whole vessel and ensuring that the angle of insonation is less than 30º. When three similar consecutive waveforms are obtained the PI must be measured and the mean PI of the left and right arteries is calculated.
(Protocol from Fetal Medicine Foundation. More information about the free online course in measurement of uterine artery PI )
- Poon LC, Staboulidou I, Maiz N, Plasencia W, Nicolaides KH. Ultrasound Obstet Gynecol. 2009 Aug;34(2):142-8.
Hypertensive disorders in pregnancy: screening by uterine artery Doppler at 11-13 weeks
- Plasencia W, Maiz N, Poon L, Yu C, Nicolaides KH.Ultrasound Obstet Gynecol. 2008 Aug;32(2):138-46.
Uterine artery Doppler at 11 + 0 to 13 + 6 weeks and 21 + 0 to 24 + 6 weeks in the prediction of pre-eclampsia.
- Plasencia W, Maiz N, Bonino S, Kaihura C, Nicolaides KH. Ultrasound Obstet Gynecol. 2007 Oct;30(5):742-9.
Uterine artery Doppler at 11 + 0 to 13 + 6 weeks in the prediction of pre-eclampsia.
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Information provided within the Overview of Pre-eclampsia is for information purposes only and not intended to be construed as medical guidance. Always contact your healthcare professional for assessment and direction regarding your health.