Prenatal Diagnosis Of Congenital Anomalies

Eunice Kennedy Shriver National Institute Of Child Health & Human Development

Investigators

Linked publications & trials

Abstract

1. Individualized growth assessment of fetal thigh circumference using three-dimensional ultrasonography.[unreadable] Estimated fetal weight and growth are usually determined using formulas that include fetal biometric parameters measured by 2D ultrasound. Investigators of our Branch conducted a prospective, longitudinal sonographic study of 30 fetuses beginning at 18 weeks' menstrual age to develop individualized growth assessment (IGA) standards for upper and middle fetal thigh circumferences using 3D ultrasonography. Second-trimester sonographic parameters were measured from three-dimensional volume data to establish IGA standards. Third-trimester growth trajectories and birth measurements were subsequently predicted for upper and middle fetal thigh circumferences, and the 95% ranges for Growth Potential Realization Index (GPRI) values for both types of thigh circumference were determined. The 30 newborns had no postnatal evidence of abnormal growth. Two examiners demonstrated a satisfactory measurement bias of 2.1% +/- 3.6 (mean + SD) for middle fetal thigh circumferences and 3.3% +/- 4.1 for upper fetal thigh circumferences. Third-trimester growth trajectories, derived from second-trimester slopes for individual fetuses, had third-trimester deviations of 0.07 +/- 3.7% for upper fetal thigh circumferences and -0.04 +/- 3.7% for middle fetal thigh circumferences. Fetal thigh circumference can be evaluated and measured reliably using standard IGA methods. Both upper and middle thigh circumferences give similar results in the third trimester. However, neonatal thigh circumference predictions are improved by using middle thigh circumferences. Corresponding GPRI values for fetal middle thigh circumference are closer to the ideal value of 100% and can be used in calculations for assessment of neonatal growth outcome.[unreadable] [unreadable] [unreadable] 2. A systematic approach to the use of the multiplanar display in evaluation of abnormal vascular connections to the fetal heart using 4-dimensional ultrasonography.[unreadable] Conotruncal anomalies represent one fifth of all congenital heart defects diagnosed prenatally. Simultaneous display of standard views used in fetal echocardiography and their orthogonal planes may provide novel ultrasonographic views for examination of the fetal heart and its vascular connections. Our research group designed a study to determine the clinical utility of the multiplanar display in the examination of abnormal vascular connections to the fetal heart. Four-dimensional volume data sets, acquired with the spatiotemporal image correlation technique, were reviewed from four patients with abnormal vascular connections to the fetal heart. Multiplanar views of the fetal heart were used to simultaneously display standard planes used in fetal echocardiography and their corresponding orthogonal planes. This method facilitated identification of the abnormal vessels and their spatial relationships with other vascular structures. Thus, we concluded that multiplanar imaging can be used to assess abnormal vascular connections to the fetal heart and may provide novel ultrasonographic planes for fetal echocardiography using 3D and 4D ultrasonography.[unreadable] [unreadable] 3. Twin-to-twin transfusion syndrome: an antiangiogenic state?[unreadable] Twin-to-twin transfusion syndrome (TTTS) affects approximately 10-15% of monochorionic-diamniotic twin pregnancies and is diagnosed based on strict sonographic criteria. An imbalanced chronic blood flow between the donor and recipient twin through placental vascular anastomoses is the accepted pathophysiology of TTTS. Recently, vascular endothelial growth factor receptor-1 (VEGFR-1) mRNA (an anti-angiogenic factor) was demonstrated to be overexpressed only in the syncytiotrophoblast of the donor twin in some cases of TTTS. We conducted a case-control study to determine maternal plasma concentrations of the angiogenic factor placental growth factor (PlGF), and of the anti-angiogenic factors soluble VEGFR-1, and soluble endoglin (s-Eng) in monochorionic-diamniotic pregnancies between 16-26 weeks with and without TTTS. Patients with TTTS had significantly higher median plasma concentrations of s-Eng (14.8 ng/mL vs 7.8 ng/mL; P < .001) and soluble VEGFR-1 (6383.1 pg/mL vs 3220.1 pg/mL; P < .001; and lower median plasma concentrations of PlGF (115.5 pg/mL vs 359.3 pg/mL; P = .002) than those without TTTS. This is a novel finding, and suggests that an antiangiogenic state may be present in some cases of TTTS.[unreadable] [unreadable] 4. The maternal plasma soluble vascular endothelial growth factor receptor-1 concentration is elevated in SGA and the magnitude of the increase relates to Doppler abnormalities in the maternal and fetal circulation.[unreadable] Preeclampsia and pregnancy complicated by small for gestational age (SGA) fetuses share some pathophysiologic derangements, such as failure of physiologic transformation of the spiral arteries, endothelial cell dysfunction, and leukocyte activation. Soluble vascular endothelial growth factor receptor-1 (sVEGFR-1), an antagonist to vascular endothelial growth factor and placental growth factor, has been implicated in the pathophysiology of preeclampsia. Investigators at the Perinatology Research Branch designed a study to determine whether plasma concentrations of sVEGFR-1 in mothers with SGA fetuses without preeclampsia at the time of diagnosis are different from those in patients with preeclampsia or normal pregnant women. The second purpose was to examine the relationship between plasma concentrations of sVEGFR-1 and Doppler velocimetry of uterine and umbilical arteries in patients with preeclampsia and those with SGA. Mothers with SGA fetuses had a mean plasma concentration of sVEGFR-1 higher than normal pregnant women, but lower than in patients with preeclampsia. Among mothers with preeclampsia and those with SGA fetuses in whom Doppler velocimetry was performed, those with abnormalities in both uterine and umbilical artery velocimetry had the highest mean delta sVEGFR-1 plasma concentrations. These observations provide support for the participation of the soluble receptor of VEGF in the pathophysiology of SGA with abnormal uterine artery Doppler velocimetry and preeclampsia. [unreadable] [unreadable] 5. The use of inversion mode and 3D manual segmentation in volume measurement of fetal fluid-filled structures: comparison with Virtual Organ Computer-aided AnaLysis (VOCAL).[unreadable] Volume measurements obtained by three-dimensional (3D) ultrasonography are considered more accurate than those obtained by two-dimensional (2D) ultrasonography using the ellipsoid formula, among others. The Perinatology Research Branch conducted a study to compare the agreement of three techniques (VOCAL, inversion mode and manual segmentation), as well as the inter- and intra-observer agreements for volume measurements of fetal fluid-filled structures. Fifty 3D volume datasets of the fetal stomach and bladder were obtained and volume measurements were performed independently by two observers. A high degree of reliability and good agreement was observed among the three techniques. Manual segmentation and inversion mode measurements were obtained significantly faster than when the VOCAL technique was utilized. We concluded that inversion mode is a reliable method for volume calculations of fluid-filled organs, whereas manual segmentation can be used when volume measurements by VOCAL or inversion mode are technically difficult to obtain.