How to record uterine artery doppler in the first trimester

Ultrasound Obstet Gynecol 2013; 42: 478–479
Published online 8 May 2013 in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/uog.12366
How to . . .
Practical advice on imaging-based techniques and investigations with accompanying slides and videoclips online How to record uterine artery Doppler in the first trimester
*Department of Fetal Medicine, Institute for Women’s Health, University College London Hospitals, London, UK; †Harris BirthrightResearch Centre for Fetal Medicine, King’s College Hospital, London, UK BACKGROUND
Effective screening for pre-eclampsia can be achieved bymeasurement of the uterine artery pulsatility index (PI) at11–13 weeks’ gestation, used in combination with mater-nal history, blood pressure, serum pregnancy-associatedplasma protein-A and placental growth factor1. For afalse-positive rate of 5%, it has been estimated thatthe new combined method of screening can predict90% of cases of pre-eclampsia requiring delivery before34 weeks and 45% of cases of late-onset pre-eclampsia2,3.
Early-onset, rather than late-onset, pre-eclampsia isassociated with an increased risk of perinatal morbidityand mortality, and both short-term and long-termmaternal complications. Early identification of women atrisk of developing pre-eclampsia and growth restrictionis likely to facilitate targeted antenatal surveillance and Figure 1 Parasagittal section of the uterus and cervix. Color flow
possibly intervention. It would also potentially avoid mapping is used to identify the uterine arteries as aliasing vessels the development of serious complications, through coursing along the side of the cervix and uterus.
interventions such as administration of low-dose aspirinand antihypertensive medication, and early delivery4.
For uterine artery PI measurement, the gestational age PRACTICAL POINTS
must be between 11 + 0 and 13 + 6 weeks. Transabdom-inal ultrasound should be used to obtain a midsagittalsection of the uterus and cervical canal. The internal 1. Obtain a sagittal section of the uterus and cervical cervical os should be identified and the transducer tilted canal. Zoom to the area of interest.
gently from side to side in each paracervical region, using 2. Identify the internal cervical os. Gently tilt the color flow mapping, to identify the uterine arteries as transducer from side to side using color flow mapping aliasing vessels coursing along the side of the cervix and to identify the uterine arteries. When you apply color uterus (Figure 1). Pulsed wave Doppler should be used Doppler, narrow the color box and adjust the velocity to obtain flow velocity waveforms from the ascending branch of the uterine artery at the point closest to the 3. Apply pulsed wave Doppler with the sampling gate internal os. When three similar consecutive waveforms set at 2 mm to cover the whole vessel. Ensure that the are obtained, the PI should be measured and the mean PI angle of insonation is < 30◦.
of the left and right arteries calculated5 (Figure 2).
4. Record at least three consecutive uniform waveforms.
Correspondence to: Prof. K. H. Nicolaides, Harris Birthright Research Centre for Fetal Medicine, King’s College Hospital, Denmark Hill,London SE5 9RS, UK (e-mail: kypros@fetalmedicine.com) Copyright  2013 ISUOG. Published by John Wiley & Sons Ltd.
Figure 2 (a) The ascending branch of the uterine artery at its paracervical portion and at the point closest to the internal os is identified and
pulsed wave Doppler is used to obtain flow velocity waveforms. (b) When three similar consecutive waveforms are obtained, the pulsatility
index (PI) should be measured and the mean PI of the left and right arteries calculated. The PI is calculated as the difference between the
peak systolic velocity (S) and the end-diastolic velocity (D), divided by the mean velocity (Vm): PI = (S−D)/Vm.
REFERENCES
age at 11–13 weeks. Fetal Diagn Ther 2012 [Epub ahead ofprint].
4. Bujold E, Roberge S, Lacasse Y, Bureau M, Audibert F, 1. Nicolaides KH. Turning the pyramid of prenatal care. Fetal Marcoux S, Forest JC, Gigu`ere Y. Prevention of pre-eclampsia Diagn Ther 2011; 29:183–196.
and intrauterine growth restriction with aspirin started in 2. Akolekar R, Syngelaki A, Sarquis R, Zvanca M, Nicolaides early pregnancy: a meta-analysis. Obstet Gynecol 2010; 116:
KH. Prediction of early, intermediate and late pre-eclampsia from maternal factors, biophysical and biochemical markers at 5. Martin AM, Bindra R, Curcio P, Cicero S, Nicolaides KH.
11–13 weeks. Prenat Diagn 2011; 31: 66–74.
Screening for pre-eclampsia and fetal growth restriction by 3. Poon LC, Syngelaki A, Akolekar R, Lai J, Nicolaides KH.
uterine artery Doppler at 11–14 weeks of gestation. Ultrasound Combined screening for preeclampsia and small for gestational Obstet Gynecol 2001; 18: 583–586.
Slides summarizing practical points, withaccompanying illustrations and videoclips,are provided as supporting informationonline.
Copyright  2013 ISUOG. Published by John Wiley & Sons Ltd.
Ultrasound Obstet Gynecol 2013; 42: 478–479.

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