Comment on “First trimester uterine artery Doppler velocimetry in the prediction of birth weight...
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CORRESPONDENCE Comment on “First trimester uterine artery Doppler velocimetry in the prediction of birth weight in a low-risk population” Sarmiento et al. 1 write eloquently about the potential role of first trimester uterine artery Doppler in the prediction of birth weight in a low-risk population. The quest to find strong associations and predictive tests for placental dysfunction leading to foetal growth restriction and stillbirth is undeniably important. In that context, these data add to the existing body of evidence that uterine artery Doppler indices, even in the first trimester, are related to subsequent birth weight. We write to seek clarity on some aspects of the study. The evaluation of first trimester uterine Doppler in the screening for preeclampsia in much larger studies has demonstrated strong associations with both the lowest and mean uterine artery Pulsatility Index, 2,3 and the authors do not make the reason for this discrepancy clear. Is it possibly because the latter studies involved thousands rather than hundreds of pregnancies and had larger numbers of pathological adverse outcomes? It has also become evident recently that even the route of ultrasound and the site of Doppler insonation can significantly influence the indices obtained. 4 Indeed, in the only large scale, prospective study on the role of first trimester uterine Doppler in the prediction of placental insufficiency and foetal size, moderate sensitivity was demonstrated once the correct definitions for fetal growth restriction were applied. 5 We postulate that the prediction of low birth weight by uterine Doppler may be further improved with the use of customised birth weight centiles or including longitudinal uterine Doppler data from the second trimester. 6,7 The authors did not evaluate the performance of the test in the detection of small babies, which would be expected to be relatively poor because only two babies had a birth weight below the 5th centile in the study cohort. To evaluate the diagnostic utility of a particular assessment, multilogistic regression or Receiver Operating Characteristic curve analysis should have been performed rather than merely correlating uterine Doppler indices with birth weight. We applaud the authors’ work and direct them towards investigating the role of uterine Doppler together with other biomarkers in the prediction of clinically important adverse outcomes related to placental insufficiency. Raffaele Napolitano*and Basky Thilaganathan Fetal Medicine Unit, Academic Department of Obstetrics and Gynaecology St George's University of London, London, UK *Correspondence to: Raffaele Napolitano. E-mail: raffaele.napolitano@obs-gyn. ox.ac.uk Funding sources: None Conflicts of interest: None declared REFERENCES 1. Sarmiento A, Casasbuenas A, Rodriguez N, et al. First-trimester uterine artery Doppler velocimetry in the prediction of birth weight in a low-risk population. Prenat Diagn 2013;33(1):21–4. 2. Napolitano R, Rajakulasingam R, Memmo A, et al. Uterine artery Doppler screening for pre-eclampsia: comparison of the lower, mean and higher first-trimester pulsatility indices. Ultrasound Obstet Gynecol 2011;37 (5):534–7. 3. Poon LC, Staboulidou I, Maiz N, et al. Hypertensive disorders in pregnancy: screening by uterine artery Doppler at 11-13 weeks. Ultrasound Obstet Gynecol 2009;34(2):142–8. 4. Lefebvre J, Demers S, Bujold E, et al. Comparison of two different sites of measurement for transabdominal uterine artery Doppler velocimetry at 11-13 weeks. Ultrasound Obstet Gynecol 2012;40 (3):288–92. 5. Melchiorre K, Leslie K, Prefumo F, et al. First-trimester uterine artery Doppler indices in the prediction of small-for-gestational age pregnancy and intrauterine growth restriction. Ultrasound Obstet Gynecol 2009;33 (5):524–9. 6. Sankaran S, Prefumo F, Papageorghiou A, et al. Association of uterine artery Doppler resistance index and birth weight: effect of customized birth weight standards. Am J Perinatol 2009;26(7):501–5. 7. Prefumo F, Güven M, Ganapathy R, Thilaganathan B. The longitudinal variation in uterine artery blood flow pattern in relation to birth weight. Obstet Gynecol 2004;103(4):764–8. Prenatal Diagnosis 2013, 33, 1317 © 2013 John Wiley & Sons, Ltd. DOI: 10.1002/pd.4106
Transcript of Comment on “First trimester uterine artery Doppler velocimetry in the prediction of birth weight...
CORRESPONDENCE
Comment on “First trimester uterine artery Doppler velocimetry inthe prediction of birth weight in a low-risk population”
Sarmiento et al.1 write eloquently about the potential role offirst trimester uterine artery Doppler in the prediction of birthweight in a low-risk population. The quest to find strongassociations and predictive tests for placental dysfunctionleading to foetal growth restriction and stillbirth is undeniablyimportant. In that context, these data add to the existing bodyof evidence that uterine artery Doppler indices, even in thefirst trimester, are related to subsequent birth weight. We writeto seek clarity on some aspects of the study. The evaluationof first trimester uterine Doppler in the screening forpreeclampsia in much larger studies has demonstratedstrong associations with both the lowest and mean uterineartery Pulsatility Index,2,3 and the authors do not make thereason for this discrepancy clear. Is it possibly because thelatter studies involved thousands rather than hundreds ofpregnancies and had larger numbers of pathological adverseoutcomes? It has also become evident recently that even theroute of ultrasound and the site of Doppler insonation cansignificantly influence the indices obtained.4 Indeed, in theonly large scale, prospective study on the role of first trimesteruterine Doppler in the prediction of placental insufficiencyand foetal size, moderate sensitivity was demonstrated oncethe correct definitions for fetal growth restriction wereapplied.5 We postulate that the prediction of low birth weight
by uterine Doppler may be further improved with the use ofcustomised birth weight centiles or including longitudinaluterine Doppler data from the second trimester.6,7 Theauthors did not evaluate the performance of the test in thedetection of small babies, which would be expected to berelatively poor because only two babies had a birth weightbelow the 5th centile in the study cohort. To evaluate thediagnostic utility of a particular assessment, multilogisticregression or Receiver Operating Characteristic curve analysisshould have been performed rather than merely correlatinguterine Doppler indices with birth weight. We applaud theauthors’ work and direct them towards investigating the roleof uterine Doppler together with other biomarkers in theprediction of clinically important adverse outcomes relatedto placental insufficiency.
Raffaele Napolitano*and Basky Thilaganathan
Fetal Medicine Unit, Academic Department of Obstetrics and Gynaecology StGeorge's University of London, London, UK*Correspondence to: Raffaele Napolitano. E-mail: [email protected]
Funding sources: NoneConflicts of interest: None declared
REFERENCES1. Sarmiento A, Casasbuenas A, Rodriguez N, et al. First-trimester uterine
artery Doppler velocimetry in the prediction of birth weight in a low-riskpopulation. Prenat Diagn 2013;33(1):21–4.
2. Napolitano R, Rajakulasingam R, Memmo A, et al. Uterine artery Dopplerscreening for pre-eclampsia: comparison of the lower, mean and higherfirst-trimester pulsatility indices. Ultrasound Obstet Gynecol 2011;37(5):534–7.
3. Poon LC, Staboulidou I, Maiz N, et al. Hypertensive disorders inpregnancy: screening by uterine artery Doppler at 11-13weeks.Ultrasound Obstet Gynecol 2009;34(2):142–8.
4. Lefebvre J, Demers S, Bujold E, et al. Comparison of two differentsites of measurement for transabdominal uterine artery Doppler
velocimetry at 11-13 weeks. Ultrasound Obstet Gynecol 2012;40(3):288–92.
5. Melchiorre K, Leslie K, Prefumo F, et al. First-trimester uterine arteryDoppler indices in the prediction of small-for-gestational age pregnancyand intrauterine growth restriction. Ultrasound Obstet Gynecol 2009;33(5):524–9.
6. Sankaran S, Prefumo F, Papageorghiou A, et al. Association of uterineartery Doppler resistance index and birth weight: effect of customizedbirth weight standards. Am J Perinatol 2009;26(7):501–5.
7. Prefumo F, Güven M, Ganapathy R, Thilaganathan B. The longitudinalvariation in uterine artery blood flow pattern in relation to birth weight.Obstet Gynecol 2004;103(4):764–8.
Prenatal Diagnosis 2013, 33, 1317 © 2013 John Wiley & Sons, Ltd.
DOI: 10.1002/pd.4106
