16 research outputs found

    Role of early second-trimester uterine artery Doppler screening to predict small-for-gestational-age babies in nulliparous women

    Get PDF
    Background Trophoblastic invasion of the uterine spiral arteries substantially increases compliance to accommodate increased blood flow to the placenta. Failure of this process impedes uterine artery blood flow, and this may be detected by uterine artery Doppler flow studies. However, the clinical utility of uterine artery Doppler flow studies in the prediction of adverse pregnancy outcomes in a general population remains largely unknown. Objective We sought to determine the utility of early second-trimester uterine artery Doppler studies as a predictor of small-for-gestational-age neonates. Study Design Nulliparous women with a viable singleton pregnancy were recruited during their first trimester into an observational prospective cohort study at 8 institutions across the United States. Participants were seen at 3 study visits during pregnancy and again at delivery. Three indices of uterine artery Doppler flow (resistance index, pulsatility index, and diastolic notching) were measured in the right and left uterine arteries between 16 weeks 0 days’ and 22 weeks 6 days’ gestation. Test characteristics for varying thresholds in the prediction of small for gestational age (defined as birthweight <5th percentile for gestational age [Alexander growth curve]) were evaluated. Results Uterine artery Doppler indices, birthweight, and gestational age at birth were available for 8024 women. Birthweight <5th percentile for gestational age occurred in 358 (4.5%) births. Typical thresholds for the uterine artery Doppler indices were all associated with birthweight <5th percentile for gestational age (P < .0001 for each), but the positive predictive values for these cutoffs were all <15% and areas under receiver operating characteristic curves ranged from 0.50-0.60. Across the continuous scales for these measures, the areas under receiver operating characteristic curves ranged from 0.56-0.62. Incorporating maternal age, early pregnancy body mass index, race/ethnicity, smoking status prior to pregnancy, chronic hypertension, and pregestational diabetes in the prediction model resulted in only modest improvements in the areas under receiver operating characteristic curves ranging from 0.63-0.66. Conclusion In this large prospective cohort, early second-trimester uterine artery Doppler studies were not a clinically useful test for predicting small-for-gestational-age babies

    Evaluation of a novel screening method for fetal aneuploidy using cell-free DNA in maternal plasma

    No full text
    Objective: To evaluate the test performance of a novel sequencing technology using molecular inversion probes applied to cell-free DNA screening for fetal aneuploidy. Methods: Two cohorts were included in the evaluation; a risk-based cohort of women receiving diagnostic testing in the first and second trimesters was combined with stored samples from pregnancies with fetuses known to be aneuploid or euploid. All samples were blinded to testing personnel before being analyzed, and validation occurred after the study closed and results were merged. Results: Using the new sequencing technology, 1414 samples were analyzed. The findings showed sensitivities and specificities for the common trisomies and the sex chromosome aneuploidies at >99% (Trisomy 21 sensitivity 99.2 CI 95.6-99.2; specificity 99.9 CI 99.6-99.9). Positive predictive values among the trisomies varied from 85.2% (Trisomy 18) to 99.0% (Trisomy 21), reflecting their prevalence rates in the study. Comparisons with a meta-analysis of recent cell-free DNA screening publications demonstrated equivalent test performance. Conclusion: This new technology demonstrates equivalent test performance compared with alternative sequencing approaches, and demonstrates that each chromosome can be successfully interrogated using a single probe
    corecore