Faculty Bibliography

This article discusses the clinical use of three-dimensional technology while performing a fetal neuroscan. This technique allows us to better define the spatial relationship of brain structures and possible malformations. The varieties of display modes and the infinite number of different planes that can be generated facilitate the diagnostic process. Additional values of this technology include an off-line analysis of the volume by the sonographer or sonologist to obtain the necessary planes, as well as an electronic transmittal for an off-site expert to provide a second opinion consultation. This modality requires a short acquisition time, allowing high patient through-put and increased patient satisfaction. In addition, it is an excellent teaching tool and provides valuable information to consulting such experts as pediatric surgeons, plastic surgeons, neonatologists, neurologists and neurosurgeons

Sonographic evaluation of the fetal vertebral column is essential for fetal central nervous system evaluation and valuable for ruling out genetic conditions. This article provides an overview for obtaining and manipulating fetal vertebrae three-dimensional data as to obtain the necessary diagnostic views. Additional technical information is provided elsewhere in this issue. This discussion is limited to include only the most common fetal vertebral abnormalities. The same technical principals, however, enable detection of many additional abnormalities

Visual information from 2-D images may be limited in reflecting a 3-D structural reality. 3-D techniques have emerged enabling acquisition of an entire volume of spatial ultrasound information that can be analyzed and displayed in multiple planes and display modes that exceed the capacities of 2-D US and better reflect the 3-D nature of a structure or anomaly. In the future 3-D evaluation of the fetal body will be an inherent part of fetal study in cases of congenital anomaly' specifically fetal brain abnormality. This article focuses on the technique for obtaining and analyzing acquired volumes and displaying them

OBJECTIVE: To evaluate the performance of first- and second-trimester screening methods for the detection of aneuploidies other than Down syndrome. METHODS: Patients with singleton pregnancies at 10 weeks 3 days through 13 weeks 6 days of gestation were recruited at 15 U.S. centers. All patients had a first-trimester nuchal translucency scan, and those without cystic hygroma had a combined test (nuchal translucency, pregnancy-associated plasma protein A, and free beta-hCG) and returned at 15-18 weeks for a second-trimester quadruple screen (serum alpha-fetoprotein, total hCG, unconjugated estriol, and inhibin-A). Risk cutoff levels of 1:300 for Down syndrome and 1:100 for trisomy 18 were selected. RESULTS: Thirty-six thousand one hundred seventy-one patients completed first-trimester screening, and 35,236 completed second-trimester screening. There were 77 cases of non-Down syndrome aneuploidies identified in this population; 41 were positive for a cystic hygroma in the first trimester, and a further 36 had a combined test, of whom 29 proceeded to quadruple screening. First-trimester screening, by cystic hygroma determination or combined screening had a 78% detection rate for all non-Down syndrome aneuploidies, with an overall false-positive rate of 6.0%. Sixty-nine percent of non-Down syndrome aneuploidies were identified as screen-positive by the second-trimester quadruple screen, at a false-positive rate of 8.9%. In the combined test, the use of trisomy 18 risks did not detect any additional non-Down syndrome aneuploidies compared with the Down syndrome risk alone. In second-trimester quadruple screening, a trisomy 18-specific algorithm detected an additional 41% non-Down syndrome aneuploidies not detected using the Down syndrome algorithm. CONCLUSION: First-trimester Down syndrome screening protocols can detect the majority of cases of non-Down aneuploidies. Addition of a trisomy 18-specific risk algorithm in the second trimester achieves high detection rates for aneuploidies other than Down syndrome. LEVEL OF EVIDENCE: II

OBJECTIVE: To assess the impact of birth defects on preterm birth and low birth weight. METHODS: Data from a large, prospective multi-center trial, the First and Second Trimester Evaluation of Risk (FASTER) Trial, were examined. All live births at more than 24 weeks of gestation with data on outcome and confounders were divided into two comparison groups: 1) those with a chromosomal or structural abnormality (birth defect) and 2) those with no abnormality detected in chromosomes or anatomy. Propensity scores were used to balance the groups, account for confounding, and reduce the bias of a large number of potential confounding factors in the assessment of the impact of a birth defect on outcome. Multiple logistic regression analysis was applied. RESULTS: A singleton liveborn infant with a birth defect was 2.7 times more likely to be delivered preterm before 37 weeks of gestation (95% confidence interval [CI] 2.3-3.2), 7.0 times more likely to be delivered preterm before 34 weeks (95% CI 5.5-8.9), and 11.5 times more likely to be delivered very preterm before 32 weeks (95% CI 8.7-15.2). A singleton liveborn with a birth defect was 3.6 times more likely to have low birth weight at less than 2,500 g (95% CI 3.0-4.3) and 11.3 times more likely to be very low birth weight at less than 1,500 g (95% CI 8.5-15.1). CONCLUSION: Birth defects are associated with preterm birth and low birth weight after controlling for multiple confounding factors, including shared risk factors and pregnancy complications, using propensity scoring adjustment in multivariable regression analysis. The independent effects of risk factors on perinatal outcomes such as preterm birth and low birth weight, usually complicated by numerous confounding factors, may benefit from the application of this methodology, which can be used to minimize bias and account for confounding. Furthermore, this suggests that clinical and public health interventions aimed at preventing birth defects may have added benefits in preventing preterm birth and low birth weight. LEVEL OF EVIDENCE: II