First-trimester visualization of the fourth ventricle in fetuses with and without spina bifida.

OBJECTIVES: The purpose of this study was to examine the efficacy of nonvisualization of the fourth ventricle for first-trimester detection of spina bifida. METHODS: A total of 250 digitally stored sonographic examinations at gestational ages of 11 weeks to 13 weeks 6 days (245 normal and 5 randomly interspersed spina bifida cases) were retrospectively analyzed by 4 blinded reviewers for the presence or absence of the fourth ventricle followed by an anteroposterior ventricular dimension measurement. The ventricle size was related to the crown-rump length and gestational age by linear regression analysis and Pearson correlation. RESULTS: The fourth ventricle was identified in 971 of 1000 image readings (97.1%). False-negative and false-positive readings occurred in 11 of 20 (55.0%) and 20 of 980 (2.0%) cases, respectively (sensitivity, 0.45; specificity, 0.98.). False-negative and false-positive readings were evenly distributed throughout the gestational age range. When the ventricular size was measurable, its mean dimensions increased linearly with gestational age and were below the fifth percentile in 10 of 245 (4.0%) normal and 0 of 4 spina bifida cases, respectively. Intraclass correlation coefficient estimates were calculated based on the 2-way analysis of variance model and found to be 0.30 for a single rater and 0.64 for the mean of 4 raters. CONCLUSIONS: Nonvisualization of the first-trimester fourth ventricle is a less robust screening parameter for spina bifida than previously published.

Teaching 3-dimensional fetal ultrasound: a randomized study.

OBJECTIVE: Three-dimensional ultrasound has become an integral mode of fetal imaging. However, unclear but foundational concepts such as 'rotational axes' and 'sectional planes' are key to obtaining, manipulating, and understanding 3d volumes. This randomized study utilized 'analogical transfer', as a novel method of teaching three-dimensional ultrasound. We hypothesized that the cognitive processing of medical professionals dealing with medical imaging is less structure-based and more intuitive. METHODS: Ninety-four ultrasound education naïve subjects (50 conventional vs 44 experimental) were randomly assigned to using one of two teaching instruments to determine whether there was a difference in learning three-dimensional concepts. One instrument used the conventional approach (prose description of concepts) while the second teaching instrument used visual descriptors. Time to complete the instrument (self-learning + quiz) was recorded and quiz results were analyzed. RESULTS: One hundred potential subjects were offered participation and 94 accepted. The mean score (scale 0-8) using the analogical transfer approach was 5.32 ± 1.64 (n = 44) and using the traditional approach was 3.42 ± 1.93 (n = 50). Using an unpaired t-test, (α = 0.05), the calculated p value was 0.0001 (95% CI 1.16-2.64). CONCLUSIONS: Those subjects exposed to the analogical transfer method were more likely to better comprehend three-dimensional ultrasound concepts as represented by higher quiz scores.

Methamphetamine use during pregnancy: maternal and neonatal implications.

OBJECTIVE: To report the demographic characteristics and clinical morbidity of methamphetamine-exposed pregnancies compared with control patients in a tertiary care, urban, academic medical center. METHODS: A single-site chart review from 2000 to 2006 was conducted. International Classification of Diseases, 9th Revision code 648.3x was used to identify potential study participants. Specific inclusion criteria required either a positive urine drug screen for methamphetamine use or by patient statement of methamphetamine use during pregnancy. Data from 276 identified patients were then compared with the 34,055 in the general obstetric population during the same period for various demographic factors and perinatal outcomes. RESULTS: Two hundred seventy-six patients responsible for 273 live births were identified between 2000 and 2006. Factors that were significantly associated with methamphetamine use were age younger than 20 years (9% methamphetamine compared with 16% control patients), non-Hispanic white ethnicity (55% compared with 71%), married (12% compared with 46%), preterm delivery (52% compared with 17%), low Apgar scores (6% compared with 1-2%), cesarean delivery (29% compared with 23%), and neonatal mortality (4% compared with 1%). Additionally, the maternal demographic characteristics suggested that these women were more likely to be unemployed, use other abusive substances, and have higher rates of domestic violence and adoption when compared with the control population. CONCLUSION: Methamphetamine use in pregnancy is complicated by more morbid maternal and neonatal outcomes when compared with the general obstetric population. Because the patients in this study were in a variety of ways demographically distinct, attempts to identify these patients early and intervene in an effort to improve pregnancy-related outcomes appears possible and warranted. LEVEL OF EVIDENCE: II.