Doppler assessment of the fetus with intrauterine growth restriction
2012; Elsevier BV; Volume: 206; Issue: 4 Linguagem: Inglês
10.1016/j.ajog.2012.01.022
ISSN1097-6868
AutoresEliza Berkley, Suneet P. Chauhan, Alfred Abuhamad,
Tópico(s)Gestational Diabetes Research and Management
ResumoObjectiveWe sought to provide evidence-based guidelines for utilization of Doppler studies for fetuses with intrauterine growth restriction (IUGR).MethodsRelevant documents were identified using PubMed (US National Library of Medicine, 1983 through 2011) publications, written in English, which describe the peripartum outcomes of IUGR according to Doppler assessment of umbilical arterial, middle cerebral artery, and ductus venosus. Additionally, the Cochrane Library, organizational guidelines, and studies identified through review of the above were utilized to identify relevant articles. Consistent with US Preventive Task Force suggestions, references were evaluated for quality based on the highest level of evidence, and recommendations were graded.Results and RecommendationsSummary of randomized and quasirandomized studies indicates that, among high-risk pregnancies with suspected IUGR, the use of umbilical arterial Doppler assessment significantly decreases the likelihood of labor induction, cesarean delivery, and perinatal deaths (1.2% vs 1.7%; relative risk, 0.71; 95% confidence interval, 0.52–0.98). Antepartum surveillance with Doppler of the umbilical artery should be started when the fetus is viable and IUGR is suspected. Although Doppler studies of the ductus venous, middle cerebral artery, and other vessels have some prognostic value for IUGR fetuses, currently there is a lack of randomized trials showing benefit. Thus, Doppler studies of vessels other than the umbilical artery, as part of assessment of fetal well-being in pregnancies complicated by IUGR, should be reserved for research protocols. We sought to provide evidence-based guidelines for utilization of Doppler studies for fetuses with intrauterine growth restriction (IUGR). Relevant documents were identified using PubMed (US National Library of Medicine, 1983 through 2011) publications, written in English, which describe the peripartum outcomes of IUGR according to Doppler assessment of umbilical arterial, middle cerebral artery, and ductus venosus. Additionally, the Cochrane Library, organizational guidelines, and studies identified through review of the above were utilized to identify relevant articles. Consistent with US Preventive Task Force suggestions, references were evaluated for quality based on the highest level of evidence, and recommendations were graded. Summary of randomized and quasirandomized studies indicates that, among high-risk pregnancies with suspected IUGR, the use of umbilical arterial Doppler assessment significantly decreases the likelihood of labor induction, cesarean delivery, and perinatal deaths (1.2% vs 1.7%; relative risk, 0.71; 95% confidence interval, 0.52–0.98). Antepartum surveillance with Doppler of the umbilical artery should be started when the fetus is viable and IUGR is suspected. Although Doppler studies of the ductus venous, middle cerebral artery, and other vessels have some prognostic value for IUGR fetuses, currently there is a lack of randomized trials showing benefit. Thus, Doppler studies of vessels other than the umbilical artery, as part of assessment of fetal well-being in pregnancies complicated by IUGR, should be reserved for research protocols. Intrauterine growth restriction (IUGR) is defined as sonographic estimated fetal weight <10th percentile for gestational age.1Battaglia F.C. Lubchenko L.O. A practical classification of newborn infants by weight and gestational age.J Pediatr. 1967; 71 (Level II-3): 159-163Abstract Full Text PDF PubMed Scopus (945) Google Scholar According to the American College of Obstetricians and Gynecologists, IUGR is "one the most common and complex problems in modern obstetrics."2American College of Obstetricians and GynecologistsIntrauterine growth restriction; ACOG practice bulletin no. 12. ACOG, Washington, DC2000Google Scholar This characterization is understandable considering the various published definitions, poor detection rate, limited preventive or treatment options, multiple associated morbidities, and increased likelihood of perinatal mortality associated with IUGR. Suboptimal growth at birth is linked with impaired intellectual performance and diseases such as hypertension and obesity in adulthood.2American College of Obstetricians and GynecologistsIntrauterine growth restriction; ACOG practice bulletin no. 12. ACOG, Washington, DC2000Google ScholarQuality of evidenceThe quality of evidence for each included article was evaluated according to the categories outlined by the US Preventative Services taskforce: IProperly powered and conducted randomized controlled trial; well-conducted systematic review or metaanalysis of homogeneous randomized controlled trials.II-1Well-designed controlled trial without randomization.II-2Well-designed cohort or case-control analytic study.II-3Multiple time series with or without the intervention; dramatic results from uncontrolled experiments.IIIOpinions of respected authorities, based on clinical experience; descriptive studies or case reports; reports of expert committees.Recommendations are graded in the following categories:Level AThe recommendation is based on good and consistent scientific evidence.Level BThe recommendation is based on limited or inconsistent scientific evidence.Level CThe recommendation is based on expert opinion or consensus. The quality of evidence for each included article was evaluated according to the categories outlined by the US Preventative Services taskforce: IProperly powered and conducted randomized controlled trial; well-conducted systematic review or metaanalysis of homogeneous randomized controlled trials.II-1Well-designed controlled trial without randomization.II-2Well-designed cohort or case-control analytic study.II-3Multiple time series with or without the intervention; dramatic results from uncontrolled experiments.IIIOpinions of respected authorities, based on clinical experience; descriptive studies or case reports; reports of expert committees. Recommendations are graded in the following categories: The recommendation is based on good and consistent scientific evidence. The recommendation is based on limited or inconsistent scientific evidence. The recommendation is based on expert opinion or consensus. Current challenges in the clinical management of IUGR include accurate diagnosis of the truly growth-restricted fetus, selection of appropriate fetal surveillance, and optimizing the timing of delivery.3Baschat A.A. Arterial and venous Doppler in the diagnosis and management of early onset fetal growth restriction.Early Hum Dev. 2005; 81 (Level III): 877-887Abstract Full Text Full Text PDF PubMed Scopus (58) Google Scholar, 4Baschat A.A. Gembruch U. Reiss I. Gortner L. Weiner C.P. Harman C.R. Relationship between arterial and venous Doppler and perinatal outcome in fetal growth restriction.Ultrasound Obstet Gynecol. 2000; 16 (Level II-2): 407-413Crossref PubMed Scopus (223) Google Scholar, 5Bilardo C.M. Wolf H. Stigter R.H. et al.Relationship between monitoring parameters and perinatal outcome in severe, early intrauterine growth restriction.Ultrasound Obstet Gynecol. 2004; 23 (Level II-1): 119-125Crossref PubMed Scopus (204) Google Scholar Despite the potential for a complicated course, antenatal detection of IUGR and its antepartum surveillance can improve outcomes. The purpose of this document is to synthesize and assess the strength of evidence of the current literature regarding the use of Doppler velocimetry of the umbilical artery, middle cerebral artery, and ductus venosus for nonanomalous fetuses with suspected IUGR, and to provide recommendations regarding antepartum management of these pregnancies, in particular for singleton gestations. We acknowledge that defining small for gestational age (birthweight 70% of arteries in placental tertiary villi.9Kingdom J.C. Burrell S.J. Kaufmann P. Pathology and clinical implications of abnormal umbilical artery Doppler waveforms.Ultrasound Obstet Gynecol. 1997; 9 (Level III): 271-286Crossref PubMed Scopus (142) Google Scholar, 10Morrow R.J. Adamson S.L. Bull S.B. Ritchie J.W. Effect of placental embolization on the umbilical artery velocity waveform in fetal sheep.Am J Obstet Gynecol. 1989; 161 (Level III): 1055-1060Abstract Full Text PDF PubMed Scopus (199) Google Scholar Absent or reversed end-diastolic flow in the umbilical artery is commonly associated with severe (birthweight 23Abdominal cord insertion (preferred), other locations acceptableOptimally done when no fetal breathingDecreased end-diastolic flow (includes AEDF, REDF)StillbirthNeurological impairmentMiddle cerebral artery>23Proximal portion of vessel at 0-degree angle of incidence>30-degree angle of incidenceIncreased diastolic flowaMay use gestational age–based table18 or subjective.Neonatal acidosisNeurological impairmentDuctus venosus>23At site of aliasing, where it branches from umbilical veinObtaining Doppler of inferior vena cavaDecreased, absent, or reversed flow in a waveNeonatal acidemiaPerinatal mortalityUterine artery18-23As it crosses the hypogastric vesselsObtaining Doppler of hypogastric artery or vaginal branch of uterine arteryNotching or elevated pulsatility indexLinked in some studies with prediction of IUGRAEDF, absent end-diastolic flow; IUGR, intrauterine growth restriction; REDF, reversed end-diastolic flow.SMFM. Doppler assessment of fetus with IUGR. Am J Obstet Gynecol 2012.a May use gestational age–based table18Kurmanavicius J. Florio I. Wisser J. et al.Reference resistance indices of the umbilical, fetal middle cerebral and uterine arteries at 24-42 weeks of gestation.Ultrasound Obstet Gynecol. 1997; 10 (Level II-2): 112-120Crossref PubMed Scopus (132) Google Scholar or subjective. Open table in a new tab AEDF, absent end-diastolic flow; IUGR, intrauterine growth restriction; REDF, reversed end-diastolic flow. SMFM. Doppler assessment of fetus with IUGR. Am J Obstet Gynecol 2012. Under normal conditions, the cerebral circulation is a high impedance circulation with continuous forward flow present throughout the cardiac cycle14Mari G. Deter R.L. Middle cerebral artery flow velocity waveforms in normal and small-for-gestational age fetuses.Am J Obstet Gynecol. 1992; 166 (Level II-3): 1262-1270Abstract Full Text PDF PubMed Scopus (256) Google Scholar (Figure 2, A) . The middle cerebral arteries, which carry >80% of the cerebral circulation, represent major branches of the circle of Willis and are the most accessible cerebral vessels for ultrasound imaging in the fetus.15Veille J.C. Hanson R. Tatum K. Longitudinal quantitation of middle cerebral artery blood flow in normal human fetuses.Am J Obstet Gynecol. 1993; 169 (Level II-3): 1393-1398Abstract Full Text PDF PubMed Scopus (38) Google Scholar The middle cerebral artery can be imaged with color Doppler ultrasound in a transverse plane of the fetal head obtained at the base of the skull. In this transverse plane, the proximal and distal middle cerebral arteries are seen in their longitudinal view, with their course almost parallel to the ultrasound beam. Middle cerebral artery Doppler waveforms, obtained from the proximal portion of the vessel immediately near the circle of Willis, have shown the best reproducibility16Mari G. Abuhamad A.Z. Cosmi E. Segata M. Altaye M. Akiyama M. Middle cerebral artery peak systolic velocity: technique and variability.J Ultrasound Med. 2005; 24 (Level II-3): 425-430PubMed Google Scholar (Table). A limited number of studies have noted that middle cerebral artery peak systolic velocity may be a better predictor of perinatal mortality in preterm IUGR than the PI, but additional study is needed to confirm this finding.17Mari G. Hanif F. Kruger M. Cosmi E. Santolaya-Forgas J. Teadwell M.C. Middle cerebral artery peak systolic velocity: a new Doppler parameter in the assessment of growth-restricted fetuses.Ultrasound Obstet Gynecol. 2007; 29 (Level II-3): 310-316Crossref PubMed Scopus (109) Google Scholar While angle of correction is not necessary when measuring the middle cerebral artery PI, peak systolic velocity measurement should use angle correction and the angle of incidence should be <30 degrees; optimally as close to 0 degrees as possible. In the presence of fetal hypoxemia, central redistribution of blood flow results in increased blood flow to the brain, heart, and adrenal glands, and a reduction in flow to the peripheral circulations. This blood flow redistribution, known as the brain-sparing reflex, is characterized by increased end-diastolic flow velocity (reflected by a low PI) in the middle cerebral artery (Figure 2, B).14Mari G. Deter R.L. Middle cerebral artery flow velocity waveforms in normal and small-for-gestational age fetuses.Am J Obstet Gynecol. 1992; 166 (Level II-3): 1262-1270Abstract Full Text PDF PubMed Scopus (256) Google Scholar, 18Kurmanavicius J. Florio I. Wisser J. et al.Reference resistance indices of the umbilical, fetal middle cerebral and uterine arteries at 24-42 weeks of gestation.Ultrasound Obstet Gynecol. 1997; 10 (Level II-2): 112-120Crossref PubMed Scopus (132) Google Scholar, 19Behrman R.E. Lees M.H. Peterson E.N. De Lannoy C.W. Seeds A.E. Distribution of the circulation in the normal and asphyxiated fetal primate.Am J Obstet Gynecol. 1970; 108 (Level II-3): 956-969Abstract Full Text PDF PubMed Scopus (279) Google Scholar Doppler assessment of brain sparing can also be assessed with the cerebroplacental ratio, defined as middle cerebral artery PI/umbilical artery PI. A fetus is considered to have fetal brain sparing when this ratio is 95th percentile for gestational age considered to be abnormal31Sciscione A.C. Hayes E.J. Society for Maternal-Fetal Medicine: uterine artery Doppler flow studies in obstetric practice.Am J Obstet Gynecol. 2009; 201 (Level III): 121-126Abstract Full Text Full Text PDF PubMed Scopus (67) Google Scholar (Table). Routine umbilical artery Doppler screening for the subsequent development of IUGR in a low-risk population has not been shown to be effective in predicting IUGR. A metaanalysis of 4 trials (n = 11,375), which included 2 studies of low-risk populations and 2 studies of unselected populations, found no significant difference in antenatal hospitalization, obstetric outcomes, or perinatal morbidities with systematic use of umbilical artery Doppler as compared with control groups.32Goffinet F. Paris-Llado J. Nisand I. Breart G. Umbilical artery Doppler velocimetry in unselected and low risk pregnancies: a review of randomized controlled trials.Br J Obstet Gynaecol. 1997; 104 (Level I): 425-430Crossref PubMed Scopus (46) Google Scholar The metaanalysis acknowledged that these 4 trials had insufficient power, and that about 30,000 women would need to be randomized to determine if routine umbilical artery Doppler screening in a low-risk population would influence perinatal mortality.32Goffinet F. Paris-Llado J. Nisand I. Breart G. Umbilical artery Doppler velocimetry in unselected and low risk pregnancies: a review of randomized controlled trials.Br J Obstet Gynaecol. 1997; 104 (Level I): 425-430Crossref PubMed Scopus (46) Google Scholar Thus, until additional randomized trials are completed, Doppler screening of the umbilical artery should not be used routinely in low-risk women to predict IUGR. Among high-risk women, there are no population-based studies regarding umbilical artery Doppler to identify pregnancies complicated by IUGR. A limited number of studies have evaluated first-trimester uterine artery Doppler velocimetry as a screening test for IUGR. However, the sensitivity is low (12%), precluding its clinical value.33Bahado-Singh R.O. Jodicke C. Uterine artery Doppler in first trimester pregnancy screening.Clin Obstet Gynecol. 2010; 53 (Level III): 879-887Crossref PubMed Scopus (22) Google Scholar The 2 largest metaanalyses regarding second-trimester uterine artery Doppler screening reached differing conclusions. Chien et al34Chien P.F. Arnott N. Gordon A. Owen P. Khon K. How useful is uterine artery Doppler flow velocimetry in the prediction of preeclampsia, intrauterine growth retardation and perinatal death? An overview.BJOG. 2000; 107 (Level I): 196-208Crossref PubMed Scopus (221) Google Scholar summarized the result of 28 studies including almost 13,000 women and noted that the likelihood ratio (LR) of an abnormal uterine artery Doppler to identify IUGR was 3.6 (95% confidence interval [CI], 3.2–4.0), and that a negative result carried a LR of 0.8 (95% CI, 0.8–0.9). Cnossen et al29Cnossen J. Morris R. Riet G. et al.Use of uterine artery Doppler ultrasonography to predict pre-eclampsia and intrauterine growth restriction: a systematic review and bivariable meta-analysis.CMAJ. 2008; 178 (Level I): 701-711Crossref PubMed Scopus (572) Google Scholar identified 61 studies with >41,000 women and noted that an increased PI with notching in low-risk women had a positive LR of 9.1 (95% CI, 5.0–16.7) for IUGR and a LR of 14.6 (95% CI, 7.8–26.3) for newborn birthweight 0.58 or >90th percentile) in the second trimester was associated with a positive LR of 10.9 (95% CI, 10.4–11.4), and a negative LR of 0.20 (95% CI, 0.14–0.26) for severe IUGR. In summary, neither umbilical nor uterine artery Doppler velocimetry is recommended as a screening tool for identifying pregnancies that will be subsequently complicated by IUGR because of inconsistent evidence of benefit, and because standards are lacking for the study technique, gestational age at testing, and criteria for abnormal test result.31Sciscione A.C. Hayes E.J. Society for Maternal-Fetal Medicine: uterine artery Doppler flow studies in obstetric practice.Am J Obstet Gynecol. 2009; 201 (Level III): 121-126Abstract Full Text Full Text PDF PubMed Scopus (67) Google Scholar Clinicians have the options of interrogating several vessels, with umbilical artery, middle cerebral artery, and ductus venosus being the ones most studied. Umbilical artery Doppler evaluation of pregnancies with suspected IUGR has been shown to significantly reduce inductions of labor (relative risk [RR], 0.89; 95% CI, 0.80–0.99), cesarean deliveries (RR, 0.90; 95% CI, 0.84–0.97), and perinatal deaths (RR, 0.71; 95% CI, 0.52–0.98; 1.2% vs 1.7%; number needed to treat = 203; 95% CI, 103–4352) without increasing the rate of unnecessary interventions.2American College of Obstetricians and GynecologistsIntrauterine growth restriction; ACOG practice bulletin no. 12. ACOG, Washington, DC2000Google Scholar, 35Alfirevic Z. Stampalija T. Gyte G.M. Fetal and umbilical Doppler ultrasound in high-risk pregnancies.Cochrane Database Syst Rev. 2010; (CD007529. Level I)Google Scholar Compared to not using this type of Doppler, the use of umbilical artery Doppler studies in women with suspected IUGR is associated therefore with maternal and perinatal benefits. Unfortunately, published studies have not typically specified an intervention protocol in response to abnormal umbilical artery Doppler testing results. Nonetheless, umbilical artery Doppler testing should be used in women with suspected IUGR, and may be used to guide the timing of delivery. Middle cerebral artery Doppler velocimetry has been found to identify a subset of IUGR fetuses at increased risk for cesarean delivery due to abnormal fetal heart rate patterns, and for neonatal acidosis.21Cruz-Martinez R. Figueras F. Hernandez-Andrade E. Oros D. Gratacos E. Fetal brain Doppler to predict cesarean delivery for nonreassuring fetal status in term small-for-gestational-age fetuses.Obstet Gynecol. 2011; 117 (Level II-1): 618-626Crossref PubMed Scopus (186) Google Scholar, 36Severi F.M. Bocchi C. Visentin A. et al.Uterine and fetal cerebral Doppler predict the outcome of third trimester small-for-gestational age fetuses with normal umbilical artery Doppler.Ultrasound Obstet Gynecol. 2002; 19 (Level II-3): 225-228Crossref PubMed Scopus (201) Google Scholar Long-term follow-up of IUGR fetuses with normal umbilical artery Doppler studies but with a middle cerebral artery PI <5th percentile reveals these infants to be at higher risk for poor neurodevelopmental outcome.37Eizarch E. Meler E. Iraola A. et al.Neurodevelopmental outcome in 2-year-old infants who were small-for-gestational age term fetuses with cerebral blood flow redistribution.Ultrasound Obstet Gynecol. 2008; 32 (Level II-2): 894-899Crossref PubMed Scopus (204) Google Scholar Despite these associations, middle cerebral artery Doppler testing of suspected IUGR fet
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