Karl Oliver Kagan

Screening for trisomy 21 by maternal age, fetal nuchal translucency thickness, free beta‐human chorionic gonadotropin and pregnancy‐associated plasma protein‐A

To derive a model and examine the performance of first‐trimester combined screening by maternal age, fetal nuchal translucency (NT) thickness and maternal serum free beta‐human chorionic gonadotropin (β‐hCG) and pregnancy‐associated plasma protein‐A (PAPP‐A).

First-trimester screening for trisomy 21 by free beta-human chorionic gonadotropin and pregnancy-associated plasma protein-A: impact of maternal and pregnancy characteristics.

To use multiple regression analysis to define the contribution of maternal variables that influence the measured concentration of free beta‐human chorionic gonadotropin (β‐hCG) and pregnancy‐associated plasma protein‐A (PAPP‐A), and the interaction between these covariates, in first‐trimester biochemical screening for trisomy 21.

A mixture model of nuchal translucency thickness in screening for chromosomal defects

Fetal nuchal translucency (NT) thickness increases with crown–rump length (CRL). In screening for chromosomal defects patient‐specific risks are derived by multiplying the a priori maternal age‐related risk by a likelihood ratio, determined from the deviation of the measured NT from the expected median. To quantify this deviation the measured NT is either subtracted (delta NT) or divided by the expected median (multiple of the median method, MoM). This study examines the validity of these methods.

Screening for trisomies 21, 18 and 13 by maternal age, fetal nuchal translucency, fetal heart rate, free β-hCG and pregnancy-associated plasma protein-A

BACKGROUNDnA beneficial consequence of screening for trisomy 21 is the early diagnosis of trisomies 18 and 13. Our objective was to examine the performance of first-trimester screening for trisomies 21, 18 and 13 by maternal age, fetal nuchal translucency (NT) thickness, fetal heart rate (FHR) and maternal serum-free beta-hCG and pregnancy-associated plasma protein-A (PAPP-A).nnnMETHODSnProspective screening for trisomy 21 by maternal age, fetal NT, free beta-hCG and PAPP-A at 11(+0)-13(+6) weeks in singleton pregnancies, including 56 376 normal cases, 395 with trisomy 21, 122 with trisomy 18 and 61 with trisomy 13. Risk algorithms were developed for the calculation of patient-specific risks for each of the three trisomies based on maternal age, NT, FHR, free beta-hCG and PAPP-A. Detection (DR) and false positive rates (FPR) were calculated and adjusted according to the maternal age distribution of pregnancies in England and Wales in 2000-2002.nnnRESULTSnThe DR and FPR were 90% and 3%, respectively, for trisomy 21, 91% and 0.2% for trisomy 18 and 87% and 0.2% for trisomy 13. When screen positivity was defined by an FPR of 3% on the risk for trisomy 21 in conjunction with an FPR of 0.2% on the maximum of the risks for trisomies 13 and 18, the overall FPR was 3.1% and the DRs of trisomies 21, 18 and 13 were 91%, 97% and 94%, respectively.nnnCONCLUSIONSnAs a side effect of first-trimester screening for trisomy 21, approximately 95% of trisomy 13 and 18 fetuses can be detected with an 0.1% increase in the FPR.

Discordance in nuchal translucency thickness in the prediction of severe twin-to-twin transfusion syndrome

To examine in monochorionic pregnancies the possible value of intertwin discordance in nuchal translucency (NT) thickness in the prediction of early fetal death or severe twin–twin transfusion syndrome (TTTS).

Ductus venosus Doppler in screening for trisomies 21, 18 and 13 and Turner syndrome at 11-13 weeks of gestation.

To investigate the performance of first‐trimester screening for aneuploidies by including assessment of ductus venosus flow in the combined test of maternal age, fetal nuchal translucency thickness, fetal heart rate, and serum free β‐human chorionic gonadotropin and pregnancy‐associated plasma protein‐A.

Tricuspid regurgitation in screening for trisomies 21, 18 and 13 and Turner syndrome at 11+0 to 13+6 weeks of gestation

To investigate the performance of first‐trimester screening for aneuploidies by including assessment of tricuspid blood flow in the combined test of maternal age, fetal nuchal translucency (NT) thickness, fetal heart rate (FHR) and serum free β‐human chorionic gonadotropin (β‐hCG) and pregnancy‐associated plasma protein A (PAPP‐A).

Fetal nasal bone in screening for trisomies 21, 18 and 13 and Turner syndrome at 11–13 weeks of gestation

To investigate the performance of first‐trimester screening for aneuploidies by including assessment of the fetal nasal bone in the combined test of maternal age, fetal nuchal translucency (NT) thickness, fetal heart rate (FHR) and serum free β‐human chorionic gonadotropin (β‐hCG) and pregnancy‐associated plasma protein‐A (PAPP‐A).

Prospective validation of first-trimester combined screening for trisomy 21

To examine the performance of the new algorithm in screening for trisomy 21 by a combination of maternal age, fetal nuchal translucency (NT) and maternal serum free β‐human chorionic gonadotropin (β‐hCG) and pregnancy‐associated plasma protein‐A (PAPP‐A).

First‐trimester ultrasound and biochemical markers of aneuploidy and the prediction of preterm or early preterm delivery

To examine the clinical utility of the first‐trimester markers of aneuploidy in their ability to predict preterm delivery.