Numbers of prenatal cell-free DNA screens performed: Results of a 2022 CAP exercise.

OBJECTIVE: Determine current analytical methods and number of cell-free (cf) DNA prenatal screening tests performed for common trisomies. METHODS: The College of American Pathologists 2022-B Noninvasive Prenatal Testing exercise was distributed in December 2022 to 93 participants in 22 countries. Supplemental questions included the number of tests performed in a recent month and the proportion of samples originating outside the United States (US). RESULTS: Eighty-three participants from three continents returned results; 74 (89%) were suitable for the analyses. Nine manufacturer/platform combinations were identified, most commonly Illumina/Nextseq (55%). The most common methodology was whole genome sequencing (76%). Annualized cfDNA tests were 2.80 million, with Asian, European and North American participants representing 10.6%, 6.5% and 82.9% of tests, respectively. When restricted to US in-country tests, the annualized rate was 2.18 million, with four of 20 participants testing 79.2%. Among 73 respondents, 63 (86%) were for-profit, eight (11%) were non-profit academic or government supported and the remaining two included hospital-based and private non-profit. Eighteen (25%) supported relevant academic training. CONCLUSION: In 2011, screening for common trisomies was based on serum/ultrasound markers with an estimated 2.96 million US pregnancies screened in 131 laboratories. In 2022, cfDNA-based screening was offered by 20 laboratories testing 2.18 million US pregnancies.

High positive predictive value 22q11.2 microdeletion screening by prenatal cell-free DNA testing that incorporates fetal fraction amplification.

OBJECTIVE: 22q11.2 deletion syndrome (DS) is a serious condition with a range of features. The small microdeletion causing 22q11.2DS makes it technically challenging to detect using standard prenatal cfDNA screening. Here, we assess 22q11.2 microdeletion clinical performance by a prenatal cfDNA screen that incorporates fetal fraction (FF) amplification. METHODS: The study cohort consisted of patients who received Prequel (Myriad Genetics, Inc.), a prenatal cfDNA screening that incorporates FF amplification, and met additional eligibility criteria. Pregnancy outcomes were obtained via a routine process for continuous quality improvement. Samples with diagnostic testing results were used to calculate positive predictive value (PPV). RESULTS: 379,428 patients met study eligibility criteria, 76 of whom were screen-positive for a de novo 22q11.2 microdeletion. 22 (29.7%) had diagnostic testing results available, and all 22 cases were confirmed as true positives, for a PPV of 100% (95% CI 84.6%-100%). This performance was based on cases that ranged broadly across FF (5.9%-41.1%, mean 23.0%), body mass index (22.3-44.8, mean 29.9), and gestational age at testing (10.0w-34.6w, median 12.7w). Ultrasound findings in screen-positive pregnancies were consistent with those known to be associated with 22q11.2DS. CONCLUSION: 22q11.2 microdeletion screening that incorporates FF amplification demonstrated high PPV across both general and high-risk population cohorts.

Performance of cell-free DNA testing for common fetal trisomies in triplet pregnancies.

OBJECTIVE: In singleton pregnancies, the use of cell-free DNA (cfDNA) analysis as a screening test for common fetal trisomies has spread worldwide though we still lack sufficient data for its use in triplet pregnancies. The objective of this study is to assess the performance of cfDNA testing in detecting fetal aneuploidies in triplet pregnancies as a first-tier test. METHOD: We performed a retrospective cohort study including data from pregnant women with a triplet pregnancy who underwent cfDNA testing between May 1, 2017, and January 15, 2020. cfDNA was obtained by massive parallel sequencing (VeriSeq NIPT solution; Illumina®). The objectives of the study were to assess the diagnostic performance of cfDNA testing for trisomy 21 (T21) (primary outcome), trisomy 18 (T18) and 13 (secondary outcomes). RESULTS: During the study period, cfDNA testing was performed in 255 women with triplet pregnancy, of which 165 (64.7%) had a neonatal outcome available. Three tests were positive for T21, one of which was confirmed by an antenatal karyotype, and the other was confirmed at birth. The third case did not undergo an invasive procedure and was not confirmed at birth (false positive). In one case, cfDNA testing was positive for T18 and was confirmed by an antenatal karyotype. There were no cases of trisomy 13 in the cohort. The no-call rate was 2.4% at first sampling. Fifty-eight (22.7%) women had embryo reduction, which in 40 (69%) of whom was performed after the cfDNA test result. CONCLUSION: cfDNA testing could be offered as primary screening for main fetal aneuploidies in triplet pregnancies after provision of appropriate patient information.

Contingent cfDNA Screening Implementation: Increasing Diagnostic Accuracy and Reducing Invasive Testing - 6 Years' Results in a Single Center.

OBJECTIVES: Universal screening for trisomy using cell-free DNA (cfDNA) has proven to be more effective than combined test, but it is not cost efficient currently. Contingent cfDNA screening on the results of the first-trimester combined test can improve the detection rate of the combined test and reduce the number of invasive tests at a lower cost than universal screening. In 2018, a contingent screening program was implemented in the community of Castilla y Leon (Spain). This study aims to compare the results achieved in Salamanca University Hospital during the first 3 years of contingent screening (2018-2020) with those of the previous 3 years (2015-2017) to assess the changes in the trisomy detection rate and the number of invasive tests. METHODS: A total of 9,903 singleton pregnancies without malformations nor nuchal translucency >p99 were included. 5,165 patients underwent combined screening and 4,738 had contingent screening based on the combined test risk. In the combined test group, women were offered an invasive test if the risk was ≥1:270, while risks under 1:270 were considered low risks, and no further testing was offered. In the contingent screening group, invasive testing was offered if the risk was ≥1:100 (≥1:50 from 2020 onwards), while cfDNA was offered if the combined test risk was between 1:100 and 1:1,000 (1:50-1:1,000 from 2020 onwards). When risk was <1:1,000, no further testing was offered. Aneuploidies detected by cfDNA were confirmed by invasive diagnostic testing. RESULTS: There were 33 cases of trisomy 21 (T21) throughout the 6 years of study. Four cases had low/intermediate risks and were spotted by cfDNA. Risk >1:1,000 threshold for contingent test detected 100% T21. There was a false-positive result for trisomy 13. There were no false-negative results. "No-call" cfDNA results were minimized by repeating blood collection 2 weeks later, as fetal fraction (FF) was doubled. Invasive testing had a drop rate of 84% after contingent screening implementation. DISCUSSION: The implementation of population-based contingent screening significantly reduces the number of invasive tests without lowering diagnostic accuracy. To achieve the maximum efficiency of the program, it is important to know the best cut-offs according to the population where the program is to be implemented. The number of uninformative results due to low FF can be reduced by repeating the test 2 weeks after the initial extraction: this increases the FF to twice the initial one, achieving informative results and avoiding unnecessary invasive tests.

Cost of providing cell-free DNA screening for Down syndrome in Finland using different strategies.

OBJECTIVES: A financial analysis is carried out to assess costs and benefits of providing cell-free DNA screening in Finland, using different strategies. METHODS: Three cell-free DNA screening strategies are considered: Primary, all women; Secondary, those with positive Combined test; and Contingent, the 10-30% with the highest Combined test risks. Three costs are estimated: additional cost for 10,000 pregnancies compared with the Combined test; 'marginal' cost of avoiding a Down syndrome birth which occurs in a pregnancy that would have been false-negative using the Combined test; and marginal cost of preventing the iatrogenic loss of a non-Down syndrome birth which occurs in a pregnancy that would have been false-positive. RESULTS: Primary cell-free DNA will require additional funds of €250,000. The marginal cost per Down syndrome birth avoided is considerably less than the lifetime medical and indirect cost; the marginal cost per unaffected iatrogenic fetal loss prevented is higher than one benefit measure but lower than another. If the ultrasound component of the Combined test is retained, as would be in Finland, the additional funds required rise to €992,000. Secondary cell-free DNA is cost-saving as is a Contingent strategy with 10% selected but whilst when 20-30% costs rise they are much less than for the Primary strategy and are cost-beneficial. CONCLUSIONS: When considering the place of cell-free DNA screening it is important to make explicit the additional and marginal costs of different screening strategies and the associated benefits. Under most assumptions the balance is favorable for Contingent screening.

The rate of undetectable genetic causes by Cell-free DNA test in congenital heart defects.

OBJECTIVE: The study aimed to estimate the rate of genetic causes that were undetectable by Cell-free DNA (cfDNA) test in prenatally diagnosed congenital heart defect (CHD) cases based on an assumption that cfDNA would accurately detect common aneuploidies including trisomy 21/18/13/45X, and del22q11.2. METHODS: This study included prenatally diagnosed CHD cases with diagnostic genetic results. The possibility of false-positive/negative results from cfDNA testing was discarded. Thus, cfDNA results would be positive in common aneuploidies or del22q11.2 and negative in normal diagnostic genetic testing results or other genetic conditions. The rate of genetic causes that were undetectable by cfDNA test was estimated for all cases as well as for CHD subgroups. RESULTS: Of 302 cases, 98 (34.8%) had a type of genetic abnormalities, with 67 having common aneuploidies or del22q11.2 and 31 having other genetic conditions. The rate of genetic causes that were undetectable by cfDNA test in CHD cases was 13.2% among those with assumingly negative cfDNA screen results and 10.3% among the entire study population. These rates were similar between CHD subgroups (p > .05). The rate of genetic causes that were undetectable by cfDNA test was higher in the non-isolated cases than in the isolated ones among those with assumingly negative-screen results (20.5% and 9.9%, respectively, p = .025). CONCLUSION: In prenatally diagnosed CDH cases, a significant number of chromosomal abnormalities are still identified after diagnostic testing even if cfDNA screen is negative, and thus it is important to extensively counsel patients with negative cfDNA screen carrying a CHD-affected fetus.

Circulating trophoblast cell clusters for early detection of placenta accreta spectrum disorders.

Placenta accreta spectrum (PAS) is a high-risk obstetrical condition associated with significant morbidity and mortality. Current clinical screening modalities for PAS are not always conclusive. Here, we report a nanostructure-embedded microchip that efficiently enriches both single and clustered circulating trophoblasts (cTBs) from maternal blood for detecting PAS. We discover a uniquely high prevalence of cTB-clusters in PAS and subsequently optimize the device to preserve the intactness of these clusters. Our feasibility study on the enumeration of cTBs and cTB-clusters from 168 pregnant women demonstrates excellent diagnostic performance for distinguishing PAS from non-PAS. A logistic regression model is constructed using a training cohort and then cross-validated and tested using an independent cohort. The combined cTB assay achieves an Area Under ROC Curve of 0.942 (throughout gestation) and 0.924 (early gestation) for distinguishing PAS from non-PAS. Our assay holds the potential to improve current diagnostic modalities for the early detection of PAS.

Serum complement proteomics reveal biomarkers for hypertension disorder of pregnancy and the potential role of Clusterin.

INTRODUCTION: Hypertension disorder of pregnancy (HDP) is one of the leading causes of maternal and foetal illness. The aim of the current study was to identify and verify novel serum markers for HDP. METHODS: A label-free LC-MS/MS method was used to establish the serum proteomic profiles of 12 pre-HDP (before clinical diagnosis of HDP) pregnancies and verify prioritized candidates in the verification set of 48 pre-HDP pregnancies. These biomarkers were revalidated by ELISA in an independent cohort of 88 pre-HDP pregnancies. Subsequently, the candidate biomarkers were histologically analysed by immunohistochemistry, and function was evaluated in TEV-1 cells. RESULTS: We identified 33 proteins with significantly increased abundance and 14 with decreased abundance (peptide FDR ≤ 1%, P < 0.05). Complement was one of the top enriched components in the pre-HDP group compared with the control group. Three complement factors (CLU, CFHR5, and CRP) were significantly increased in the three sets, of which CLU was a critical factor for the development of HDP (OR = 1.22, P < 0.001). When these three factors and body weight were combined, the AUC was 0.74, with a sensitivity of 0.67 and specificity of 0.68 for HDP prediction compared with normal pregnancy. In addition, inflammation-induced CLU could inhibit the invasion of TEV-1 cells. CONCLUSIONS: Complement proteins may play an essential role in the occurrence of HDP by acting on trophoblast cells. CLU may be a high-risk factor for HDP, and the models combining candidates show reasonable screening efficiency of HDP in the first half of pregnancy.

Can complete blood count parameters that change according to trimester in pregnancy be used to predict severe preeclampsia?

We aimed to evaluate the effectiveness of changes over time in complete blood count (CBC) parameters to estimate the diagnosis of preeclampsia. Data on 161 severe preeclampsia patients and 161 healthy pregnant patients who met the study criteria of pregnant women whose CBC had been measured at 10-12, 22-24 and 28-30 weeks of pregnancy were compared. In the preeclampsia group, an increase in the mean platelet volume (MPV) value and a decrease in the number of platelets were statistically significant in the transition from the second to the third trimester. MPV and lymphocyte counts were more significant in the third trimester and neutrophil lymphocyte ratio (NLR) were more significant in the second trimester. We found that evaluation of the changes in lymphocyte, MPV and NLR values in three different trimesters of pregnancy rather than a single trimester was more meaningful to predict severe preeclampsia.Impact StatementWhat is already known on this subject? Studies have shown that MPV and NLR can predict preeclampsia. However, a clear cut off value could not be determined. The reasons for this may be that the gestational week during which the measurement is made is not standard and the patient groups are not homogeneous.What the results of this study add? In this study, CBC parameters at different stages of the preeclampsia process were compared in the severe preeclampsia group. According to our results, lymphocytes, NLR and MPV can be used to predict severe preeclampsia. In addition, NLR measurements in the second trimester and MPV and lymphocyte measurements in the third trimester were found to be more significant in predicting severe preeclampsia.What the implications are of these findings for clinical practice and/or further research? In order to predict severe preeclampsia, instead of a single measurement of CBC parameters, new calculations should be made that add change over time.

Cell-free DNA analysis of maternal blood in prenatal screening for chromosomal microdeletions and microduplications: a systematic review.

BACKGROUND AND AIM OF THE STUDY: Scientific Societies do not recommend the use of cell-free DNA (cfDNA) testing as a first-tier screening for microdeletion and microduplication syndromes (MMs). The aim of this study was to review the current available literature on the performance of cell-free DNA as a screening for MMs. METHODS: Medline, Embase and the Cochrane Library were searched electronically from 2000 to January 2020 and articles reporting the diagnostic performance of cfDNA screening for MMs in large (>5000 cases) series were included. Between-study heterogeneity and random effect model for screen positive rate (SPR), false positive rate (FPR) and positive predictive value (PPV) were calculated. RESULTS: We identified 42 papers, seven included, for a total of 474,189 pregnancies and 210 cases of MMs. Diagnostic verification of positive cases was available overall in 486 (71.68 %) of 678 cases. The weighted pooled SPR, FPR and PPV were 0.19% (95% CI = 0.09-0.33), 0.07 (95% CI = 0.02-0.15) and 44.1 (95% CI = 31.49-63.07). In conclusion, the pooled PPV of cfDNA testing in screening for MMs was about 40%, ranging from 29% to 91%, for an overall FPR <0.1%. CONCLUSIONS: No confirmatory analysis was available in cases that did not undergo invasive testing, which were the vast majority of cases with a negative test, and therefore, the DR and the negative predictive value cannot be determined.

Noninvasive prenatal screening in twin pregnancies with cell-free DNA using the IONA test: a prospective multicenter study.

BACKGROUND: In singleton pregnancies, studies investigating cell-free DNA in maternal blood have consistently reported high detection rate and low false-positive rate for the 3 common fetal trisomies (trisomies 21, 18, and 13). The potential advantages of noninvasive prenatal testing in twin pregnancies are even greater than in singletons, in particular lower need for invasive testing and consequent fetal loss rate. However, several organizations do not recommend cell-free DNA in twin pregnancies and call for larger prospective studies. OBJECTIVE: In response to this, we undertook a large prospective multicenter study to establish the screening performance of cell-free DNA for the 3 common trisomies in twin pregnancies. Moreover, we combined our data with that reported in published studies to obtain the best estimate of screening performance. STUDY DESIGN: This was a prospective multicenter blinded study evaluating the screening performance of cell-free DNA in maternal plasma for the detection of fetal trisomies in twin pregnancies. The study took place in 6 fetal medicine centers in England, United Kingdom. The primary outcome was the screening performance and test failure rate of cell-free DNA using next generation sequencing (the IONA test). Maternal blood was taken at the time of (or after) a conventional screening test. Data were collected at enrolment, at any relevant invasive testing throughout pregnancy, and after delivery until the time of hospital discharge. Prospective detailed outcome ascertainment was undertaken on all newborns. The study was undertaken and reported according to the Standards for Reporting of Diagnostic Accuracy Studies. A pooled analysis was also undertaken using our data and those in the studies identified by a literature search (MEDLINE, Embase, CENTRAL, Cochrane Library, and ClinicalTrials.gov) on June 6, 2020. RESULTS: A total of 1003 women with twin pregnancies were recruited, and complete data with follow-up and reference data were available for 961 (95.8%); 276 were monochorionic and 685 were dichorionic. The failure rate was 0.31%. The mean fetal fraction was 12.2% (range, 3%-36%); all 9 samples with a 3% fetal fraction provided a valid result. There were no false-positive or false-negative results for trisomy 21 or trisomy 13, whereas there was 1 false-negative and 1 false-positive result for trisomy 18. The IONA test had a detection rate of 100% for trisomy 21 (n=13; 95% confidence interval, 75-100), 0% for trisomy 18 (n=1; 95% confidence interval, 0-98), and 100% for trisomy 13 (n=1; 95% confidence interval, 3-100). The corresponding false-positive rates were 0% (95% confidence interval, 0-0.39), 0.10% (95% confidence interval, 0-0.58), and 0% (95% confidence interval, 0-0.39), respectively. By combining data from our study with the 11 studies identified by literature search, the detection rate for trisomy 21 was 95% (n=74; 95% confidence interval, 90-99) and the false-positive rate was 0.09% (n=5598; 95% confidence interval, 0.03-0.19). The corresponding values for trisomy 18 were 82% (n=22; 95% confidence interval, 66-93) and 0.08% (n=4869; 95% confidence interval, 0.02-0.18), respectively. There were 5 cases of trisomy 13 and 3881 non-trisomy 13 pregnancies, resulting in a computed average detection rate of 80% and a false-positive rate of 0.13%. CONCLUSION: This large multicenter study confirms that cell-free DNA testing is the most accurate screening test for trisomy 21 in twin pregnancies, with screening performance similar to that in singletons and very low failure rates (0.31%). The predictive accuracy for trisomies 18 and 13 may be less. However, given the low false-positive rate, offering first-line screening with cell-free DNA to women with twin pregnancy is appropriate in our view and should be considered a primary screening test for trisomy 21 in twins.

Testing, Monitoring, and Treatment of Thyroid Dysfunction in Pregnancy.

Both hyperthyroidism and hypothyroidism can have adverse effects in pregnancy. The most common causes of thyrotoxicosis in pregnancy are gestational transient thyrotoxicosis and Graves' disease. It is important to distinguish between these entities as treatment options differ. Women of reproductive age who are diagnosed with Graves' disease should be counseled regarding the impact of treatment options on a potential pregnancy. Although the absolute risk is small, antithyroid medications can have teratogenic effects. Propylthiouracil appears to have less severe teratogenicity compared to methimazole and is therefore favored during the first trimester if a medication is needed. Women should be advised to delay pregnancy for at least 6 months following radioactive iodine to minimize potential adverse effects from radiation and ensure normal thyroid hormone levels prior to conception. As thyroid hormone is critical for normal fetal development, hypothyroidism is associated with adverse obstetric and child neurodevelopmental outcomes. Women with overt hypothyroidism should be treated with levothyroxine (LT4) to a thyrotropin (thyroid-stimulating hormone; TSH) goal of <2.5 mIU/L. There is mounting evidence for associations of maternal hypothyroxinemia and subclinical hypothyroidism with pregnancy loss, preterm labor, and lower scores on child cognitive assessment. Although there is minimal risk of LT4 treatment to keep TSH within the pregnancy-specific reference range, treatment of mild maternal thyroid hypofunction remains controversial, given the lack of clinical trials showing improved outcomes with LT4 treatment.

Association of adverse outcomes of intrahepatic cholestasis of pregnancy with zonulin levels.

Our aim was to investigate serum zonulin levels in intrahepatic cholestasis of pregnancy (ICP) and to determine the usefulness of zonulin in ICP follow-up. A prospective case-control study was carried out which included 88 pregnant women (44 patients with ICP and 44 controls). Maternal serum samples obtained from all participants and zonulin levels were determined by enzyme-linked immunosorbent assay (ELISA). Compared with controls, women with ICP had significantly higher zonulin levels (mean 0.728 ± 0.520 ng/mL vs. 1.303 ± 0.63 ng/mL, p <.001). According to the receiver operating characteristic (ROC) analysis performed for the predictive value of zonulin levels for ICP, the area under the curve (AUC) was 0.761 (95% CI: 0.661-0.860). Multivariable logistic regression analysis revealed serum zonulin levels was independently associated with adverse perinatal outcomes (OR = 1.278, 95% CI: 0.232-7.041), severity ICP (OR: 7.535, 95% CI: 1.597-13.553) and also unresponsiveness to treatment in ICP (OR: 4.178, 95% CI: 0.929-8.784).IMPACT STATEMENTWhat is already known on this subject? Zonulin is a regulator protein that increases the intestinal permeability by modulating the intercellular tight junctions (TJ). It is the only physiological protein known to control intestinal permeability and damage of the intestinal barrier is one of the causes of absorption disorders, inflammation and autoimmunity. ICP is a relatively non-threatening condition to women but is linked with a higher risk of preterm delivery, foetal distress and foetal death.What do the results of this study add? This study showed that increased levels of zonulin are associated with adverse perinatal outcomes, severity of ICP and unresponsiveness to treatment in ICP.What are the implications of these findings for clinical practice and/or further research? Focussing on preservation of intestinal permeability may be an alternative preventive strategy to reduce the adverse perinatal outcomes and severity of ICP. Further longitudinal studies are needed to verify the relationships among zonulin levels and pregnancy-related diseases.

Prenatal screening for trisomy 21: a comparative performance and cost analysis of different screening strategies.

BACKGROUND: Prenatal screening for chromosome aneuploidies have constantly been evolving, especially with the introduction of cell-free fetal DNA (cfDNA) screening in the most recent years. This study compares the performance, costs and timing of test results of three cfDNA screening implementation strategies: contingent, reflex and primary. METHODS: We modelled enhanced first trimester screening (eFTS) as the first-tier test in contingent or reflex strategies. cfDNA test was performed contingent on or reflex from eFTS results. A comparison was made between cfDNA screening using sequencing technology and Rolling Circle Amplification (RCA)/imaging solution. All model assumptions were based on results from previous publications or information from the Ontario prenatal screening population. RESULTS: At an eFTS risk cut-off of ≥1/1000, contingent and reflex cfDNA screening have the same detection rate (DR) (94%) for trisomy 21. Reflex cfDNA screening using RCA/Imaging solution provided the lowest false positive rate and cost. The number of women requiring genetic counselling and diagnostic testing was significantly reduced and women received their cfDNA screening result 9 days sooner compared with the contingent model. While primary cfDNA screening improved the trisomy 21 DR by 3-5%, it was more costly and more women required diagnostic testing. CONCLUSION: Reflex cfDNA screening is the most cost-effective prenatal screening strategy. It can improve the efficiency of prenatal aneuploidy screening by reducing the number of patient visits and providing more timely results.

Discovery and Verification of Extracellular miRNA Biomarkers for Non-invasive Prediction of Pre-eclampsia in Asymptomatic Women.

Development of effective prevention and treatment strategies for pre-eclampsia is limited by the lack of accurate methods for identification of at-risk pregnancies. We performed small RNA sequencing (RNA-seq) of maternal serum extracellular RNAs (exRNAs) to discover and verify microRNAs (miRNAs) differentially expressed in patients who later developed pre-eclampsia. Sera collected from 73 pre-eclampsia cases and 139 controls between 17 and 28 weeks gestational age (GA), divided into separate discovery and verification cohorts, are analyzed by small RNA-seq. Discovery and verification of univariate and bivariate miRNA biomarkers reveal that bivariate biomarkers verify at a markedly higher rate than univariate biomarkers. The majority of verified biomarkers contain miR-155-5p, which has been reported to mediate the pre-eclampsia-associated repression of endothelial nitric oxide synthase (eNOS) by tumor necrosis factor alpha (TNF-α). Deconvolution analysis reveals that several verified miRNA biomarkers come from the placenta and are likely carried by placenta-specific extracellular vesicles.

Indigenization of the median of markers for Down syndrome screening based on statistical analysis of medical big data.

OBJECTIVE: To indigenize the median of Down syndrome (DS) screening markers for first and second trimester, and compare the impact of the indigenized and built-in median data on the efficiency of DS screening. MATERIALS AND METHODS: Data derived from first and Second-trimester screening (FTS and STS) for DS, composed of selected pregnancies deemed to be normal, were examined in a retrospective study. Indigenization regression analysis was calculated by using five models to fit statistical the raw data. Multiple of median (MoM) values estimated by using indigenized medians were compared with those calculated by using built-in. RESULTS: This study established a regression equation which is more suitable for the median of each screening marker in the local pregnant women. The changes of median MoM of screening markers were statistically significant after indigenization. For FTS, the detection rate was 100% when the false positive rate was 5%, and the cut-off value was 1/262. On the other hand, for STS, the detection rate of the model with indigenized parameters was 77.42%, which is 16.13% higher than that of built-in parameters. CONCLUSION: For the individual specific risk of pregnancy, when the indigenized parameters was used to calculate, is more accurately and screening effectiveness has been improved. This is a great reference significance for the current prenatal screening whether indigenized data should be used.

Cell-free DNA screening in twin pregnancies: A more accurate and reliable screening tool.

OBJECTIVE: Outcome data from cell-free DNA (cfDNA) screening in twin gestations are limited. This study adds an appreciable number of confirmed outcomes to the literature, and assesses performance of cfDNA screening in twins over a 4.5-year period at one large clinical laboratory. METHOD: Prenatal cytogenetic and SNP microarray results were cross-referenced with cfDNA results for twin pregnancies, yielding 422 matched cases. Using diagnostic results as truth, performance of cfDNA screening in this population was assessed. RESULTS: Of the 422 twin pregnancies with both cfDNA and diagnostic results, 3 specimens failed amniocyte analysis, and 48 samples (11.5%) were nonreportable from the initial cfDNA draw. Analysis of the 371 reportable samples demonstrated a collective sensitivity of 98.7% and specificity of 93.2% for trisomies 21/18/13. Positive predictive values (PPVs) in this study population, which is enriched for aneuploidy, were 78.7%, 84.6%, and 66.7% for trisomy 21, 18, and 13, respectively. CONCLUSION: CfDNA screening in a cohort of twin pregnancies with matched diagnostic results showed superior performance compared to traditional serum biochemical screening in twins. This study adds to a growing body of evidence suggesting that cfDNA is an accurate and reliable screening tool for the major trisomies in twin pregnancies.

The Number of Circulating Fetal Extravillous Trophoblasts Varies from Gestational Week 6 to 20.

Cell-based non-invasive prenatal testing (cbNIPT) based on circulating fetal extravillous trophoblasts (fEVTs) has shown to be possible in gestational week (GW) 10-13. Prenatal testing is relevant for a wider time period than GW 10-13, but it is unclear if fEVTs are present in sufficient numbers for cbNIPT at other time points during pregnancy. We present the first longitudinal study where the number of circulating fEVTs was determined from the mid first trimester to the mid second, specifically GW 6-8, 12-13, and 19-20. Blood samples from 13 women opting for assisted reproduction were collected at GW 6-8, 12-13, and 19-20. fEVTs were enriched using a magnetic-activated cell sorting system, stained with anti-cytokeratin antibodies, and fEVTs were identified with the use of a MetaSystem fluorescence microscope scanner. Blood samples drawn at GW 6-8 yielded an average of 5.5 fEVTs per 30 mL of blood. This increased significantly to an average of 11.8 in GW 12-13 (P value: 0.0070, Mann-Whitney test), and decreased significantly to an average of 5.3 in GW 19-20 (P value: 0.0063, Mann-Whitney test). In 9 out of 13 cases, the number of fEVTs peaked in GW 12-13 compared to GW 6-8 and GW 19-20. For the majority of cases, fEVTs can be identified at GW 6-8 and GW 19-20, but the highest number of fEVTs is observed at GW 12-13 indicating this is the optimal time point for cbNIPT.

Reaching hard-to-reach men through home-based couple HIV testing among pregnant women and their male partners in western Kenya: a qualitative study.

BACKGROUND: Globally only 79% of adults living with HIV (human immunodeficiency virus) know their status and men in sub-Saharan Africa are considered a particularly hard-to-reach population for HIV testing. Home-based HIV couple testing during the antenatal period is a safe and effective method that has been used to test male partners of pregnant women. The goal of this qualitative study was to identify elements that made couple testing successful and describe important characteristics of this home-based intervention from couples' perspectives. METHODS: Couples who received scheduled home-based couple testing during pregnancy in Kisumu, Kenya, were purposively sampled based on HIV status from January to May 2015. An interviewer administered all of the in-depth interviews and two coders were directly involved in the data analysis and reconciled codes several times in the process. RESULTS: Twenty-one couples were enrolled: 9 concordant HIV-negative couples, 8 HIV discordant couples, 3 HIV concordant HIV-positive couples, and 1 whose concordance status was unknown. Median age at the time of home-based couple testing was 24 and 28 years for women and men, respectively. Median relationship duration was 3 years and couples had a median of two pregnancies. The major themes that emerged were that home-based couple testing 1) removed the female burden of requesting couple testing, 2) overcame logistical barriers associated with clinic-based testing, 3) encouraged participants to overcome their fear of testing and disclosure, 4) provided privacy in the home, and 5) provided quality time with the health advisors. Importantly, some women appreciated individual testing at the clinic before couple testing and some couples preferred skilled, anonymous health advisors delivering the intervention rather than known community health workers. CONCLUSIONS: The results of this qualitative study suggest that home-based couple testing during pregnancy overcame many of the barriers that limit men's access to and uptake of clinic-based testing. It encouraged participants to overcome their fear of testing and disclosure through a setting that afforded privacy and quality time with skilled health advisors. These qualitative results may help design effective partner and couple HIV testing programs in the antenatal setting and alongside or within other assisted partner notification services. TRIAL REGISTRATION: Clinicaltrials.gov registry: NCT01784783. Registered prospectively on June 15, 2012.