Expanded conventional first trimester screening.

OBJECTIVE: The study aims to determine the performance of a five (5) serum marker plus ultrasound screening protocol for T21, T18 and T13. METHOD: Specimens from 331 unaffected, 34 T21, 19 T18 and 8 T13 cases were analyzed for free Beta human chorionic gonadotropin, pregnancy-associated plasma protein A, alpha-fetoprotein, placental growth factor and dimeric inhibin A. Gaussian distributions of multiples of the median values were used to estimate modeled false positive and detection rates (DR). RESULTS: For T21, at a 1/300 risk cut-off, DR of screening with all five serum markers along with nuchal translucency and nasal bone was 98% at a 1.2% false positive rate (FPR). Using a 1/1000 cut-off, the DR was 99% with a 2.6% FPR. For T18/13 with free Beta human chorionic gonadotropin, pregnancy-associated plasma protein A, placental growth factor and nuchal translucency at a 1/150 cut-off, DR was 95% at a 0.5% FPR while at a 1/500 risk cut-off, DR was 97% at a 1.2% FPR. CONCLUSION: An expanded conventional screening test can achieve very high DRs with low FPRs. Such screening fits well with proposed contingency protocols utilizing cell-free DNA as a secondary or reflex but also provides the advantages of identification of pregnancies at risk for other adverse outcomes such as early-onset preeclampsia. © 2017 Eurofins NTD, LLC. Prenatal Diagnosis published by John Wiley & Sons, Ltd.

Evaluation of Syndecan-1 as a Novel Biomarker for Adverse Pregnancy Outcomes.

To determine if circulating levels of maternal syndecan-1, a part of the endothelial glycocalyx, change over gestational weeks 11-13 and if first trimester serum syndecan-1 levels are aberrant in women with adverse pregnancy outcomes vs. controls. Dried blood samples from 300 randomly selected women (100 each from gestational weeks 11, 12, and 13) who delivered at Northwell Health were assessed for syndecan-1 levels. Subjects were segregated by gestational age and maternal weight at the time of blood draw. Gestational age-specific medians were determined by linear regression of median syndecan-1 values vs. gestational age. Multiples of the median (MoMs) = syndecan-1/respective gestational age-specific regressed median. After determining a normal range, we performed a case-control study. Cases (n = 119) were singleton pregnancies with preeclampsia or fetal growth restriction who delivered at 20-36 6/7 weeks with 1st trimester conventional aneuploidy screens; 2 controls (n = 238) per case were identified and assessed. Syndecan-1 levels were determined by ELISA. Data were reported as MoMs and analyzed based on Wilcoxon rank-sum test and Fisher's exact test. A progressive and significant increase in median circulating Sdc1 concentrations was observed from gestational weeks 11-13 (p < 0.001). There was no significant difference in median syndecan-1 MoM values among cases and controls (p = 0.22). However, a subgroup of cases (17.6%) had extreme syndecan-1 values (≤ 0.5MoM) vs. 6.7% of controls (p = 0.003, OR = 3.0). Serum syndecan-1 concentrations significantly increase during gestational weeks 11-13. Extremely low 1st trimester serum syndecan-1 values are associated with an increased risk of adverse pregnancy outcome.

Screening for Open Neural Tube Defects.

Biochemical prenatal screening was initiated with the use of maternal serum alpha fetoprotein to screen for open neural tube defects. Screening now includes multiple marker and sequential screening protocols involving serum and ultrasound markers to screen for aneuploidy. Recently cell-free DNA screening for aneuploidy has been initiated, but does not screen for neural tube defects. Although ultrasound is highly effective in identifying neural tube defects in high-risk populations, in decentralized health systems maternal serum screening still plays a significant role. Abnormal maternal serum alpha fetoprotein alone or in combination with other markers may indicate adverse pregnancy outcome in the absence of open neural tube defects.

Impact of blood collection method on first-trimester dried blood free Beta hCG and PAPP-A.

Background Analysis of dried blood specimens has been an integral part of laboratory medicine dating back to the early 1960s when they were introduced as part of neonatal screening programs. More recently, they have been used in Down syndrome screening programmes. Dried blood spot specimens can be collected either by finger-stick or by traditional venipuncture and spotted onto filter paper. We sought to evaluate whether first-trimester free Beta hCG and PAPP-A multiples of the median (MoMs) were different in dried blood specimens collected via finger-stick compared to specimens collected via venipuncture. Methods A total of 2786 consecutive dried blood specimens were evaluated including 2144 collected using finger-stick and 644 specimens collected using venipuncture and spotted onto filter paper. Linear regression was used to assess the overall impact of collection method on dried blood free Beta hCG and PAPP-A and the impact of collection method on the trend of dried blood free Beta hCG and PAPP-A with transport time. Results For finger-stick and venipuncture, the median for free Beta hCG MoM was 0.99 and 1.04, respectively while the median PAPP-A MoM was 1.00 and 1.01, respectively. The regression formula for free Beta hCG was ln(MoM) = -0.00918 + 0.05112×Venipuncture + 0.00299×Days -0.00983×Days×Venipuncture and for PAPP-A the formula was ln(MoM) = -0.01000 + 0.04779×Venipuncture -0.00051×Days -0.02117×Days×Venipuncture. None of the coefficients were significant. Conclusions Collection method does not impact MoM values. Thus, centres have flexibility in the collection method utilized while being able to use a single reference database for all dried blood specimens.

Impact of blood collection method on first-trimester dried blood free Beta hCG and PAPP-A.

BACKGROUND: Analysis of dried blood specimens has been an integral part of laboratory medicine dating back to the early 1960s when they were introduced as part of neonatal screening programs. More recently, they have been used in Down syndrome screening programmes. Dried blood spot specimens can be collected either by finger-stick or by traditional venipuncture and spotted onto filter paper. We sought to evaluate whether first-trimester free Beta hCG and PAPP-A multiples of the median (MoMs) were different in dried blood specimens collected via finger-stick compared to specimens collected via venipuncture. METHODS: A total of 2786 consecutive dried blood specimens were evaluated including 2144 collected using finger-stick and 644 specimens collected using venipuncture and spotted onto filter paper. Linear regression was used to assess the overall impact of collection method on dried blood free Beta hCG and PAPP-A and the impact of collection method on the trend of dried blood free Beta hCG and PAPP-A with transport time. RESULTS: For finger-stick and venipuncture, the median for free Beta hCG MoM was 0.99 and 1.04, respectively while the median PAPP-A MoM was 1.00 and 1.01, respectively. The regression formula for free Beta hCG was ln(MoM) = -0.00918 + 0.05112×Venipuncture + 0.00299×Days -0.00983×Days×Venipuncture and for PAPP-A the formula was ln(MoM) = -0.01000 + 0.04779×Venipuncture -0.00051×Days -0.02117×Days×Venipuncture. None of the coefficients were significant. CONCLUSIONS: Collection method does not impact MoM values. Thus, centres have flexibility in the collection method utilized while being able to use a single reference database for all dried blood specimens.