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.

The impact of prenatal screening tests on prenatal diagnosis in Taiwan from 2006 to 2019: a regional cohort study.

BACKGROUND: The purpose of this study is to evaluate the impact of prenatal screening tests on prenatal diagnosis in Taiwan's 14 years from 2006 to 2019. METHODS: The prenatal screening methods evolved from the second-trimester serum screening to combined first-trimester screening (cFTS) and then followed by the non-invasive cell-free DNA prenatal test (NIPT). The data used by the Department of Statistics, the Ministry of Health and Welfare and Department of Household Registration, Ministry of the Interior public website. RESULTS: This regional registry-based cohort retrospective study examined a total of 2,775,792 births from January 2006 to December 2019. The proportion of advanced maternal age (AMA) pregnancies increased from 11.63% in 2006 to 30.94% in 2019. Overall, invasive diagnostic testing was used in 87.22% of AMA pregnancies. The prenatal detection rate of trisomy 21 and 18 increased from 74.1% and 83.3% in 2006 to 96.9% and 98.8% in 2019, respectively. CONCLUSION: During the second-trimester and cFTS periods, the percentage of AMA pregnancies increased every year and the number of invasive procedures also accompany with increased percentage of AMA. However, during the period that NIPT were implemented, the percentage of invasive procedures decreased.

The impact of preimplantation genetic testing for aneuploidy on prenatal screening.

OBJECTIVES: To determine whether preimplantation genetic testing for aneuploidy (PGT-A) is associated with a reduced risk of abnormal conventional prenatal screening results in singleton pregnancies conceived using in vitro fertilization (IVF). METHODS: This was a retrospective cohort study of singleton IVF pregnancies conceived from a single tertiary care center between January 2014 and September 2019. Exclusion criteria included mosaic embryo transfers, vanishing twin pregnancies, and cycles with missing outcome data. Two cases of prenatally diagnosed aneuploidy that resulted in early voluntary terminations were also excluded. The primary outcome of abnormal first or second-trimester combined screening results was compared between two groups: pregnancy conceived after transfer of a euploid embryo by PGT-A vs. transfer of an untested embryo. Multivariable backwards-stepwise logistic regression with Firth method was used to adjust for potential confounders. RESULTS: Of the 419 pregnancies included, 208 (49.6%) were conceived after transfer of a euploid embryo by PGT-A, and 211 (50.4%) were conceived after transfer of an untested embryo. PGT-A was not associated with a lower likelihood of abnormal first-trimester (adjusted OR 1.64, 95% CI 0.82-3.39) or second-trimester screening results (adjusted OR 0.96, 95% CI 0.56-1.64). The incidences of cell-free DNA testing, fetal sonographic abnormalities, genetic counseling, and invasive prenatal diagnostic testing were similar between the two groups. CONCLUSIONS: Our data suggest that PGT-A is not associated with a change in the likelihood of abnormal prenatal screening results or utilization of invasive prenatal diagnostic testing. Counseling this patient population regarding the importance of prenatal screening and prenatal diagnostic testing, where appropriate, remains essential.

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.

Prenatal diagnosis of MAGED2 gene mutation causing transient antenatal Bartter syndrome.

Transient antenatal Bartter syndrome due to melanoma-associated antigen D2 gene mutation is a newly reported type of Bartter syndrome. Its characteristics include an X-linked inheritance pattern, early-onset hydramnios, and spontaneous disappearance of symptoms after childbirth. To date, there have been no reports of prenatally diagnosed cases. We herein present the case of a preterm male born to a mother with early-onset hydramnios and a family history of X-linked idiopathic hydramnios. We suspected melanoma-associated antigen D2 gene mutation and performed direct sequencing. As a result, we were able to prenatally establish a diagnosis of transient Bartter syndrome due to a melanoma-associated antigen D2 gene mutation.

Investigation on combined copy number variation sequencing and cytogenetic karyotyping for prenatal diagnosis.

BACKGROUND: We aimed to evaluate the clinical value of copy number variation-sequencing (CNV-Seq) in combination with cytogenetic karyotyping in prenatal diagnosis. METHODS: CNV-Seq and cytogenetic karyotyping were performed in parallel for 9452 prenatal samples for comparison of the diagnostic performance of the two methods, and to evaluate the screening performance of maternal age, maternal serum screening, fetal ultrasound scanning and noninvasive prenatal testing (NIPT) for fetal pathogenic copy number variation (CNV). RESULTS: Among the 9452 prenatal samples, traditional karyotyping detected 704 cases (7.5%) of abnormal cytogenetic karyotypes, 171 (1.8%) chromosome polymorphism, 20 (0.2%) subtle structural variations, 74 (0.7%) mutual translocation (possibly balanced), 52 (0.6%) without karyotyping results, and 8431 (89.2%) normal cytogenetic karyotypes. Among the 8705 cases with normal karyotype, polymorphism, mutual translocation, or marker chromosome, CNV-Seq detected 63 cases (0.7%) of pathogenic chromosome microdeletion/duplication. Retrospectively, noninvasive prenatal testing (NIPT) had high sensitivity and specificity for the screening of fetal pathogenic CNV, and NIPT combining with maternal age, maternal serum screening or fetal ultrasound scanning, which improved the screening performance. CONCLUSION: The combined application of cytogenetic karyotyping and CNV-Seq significantly improved the detection rate of fetal pathogenic chromosome microdeletion/duplication. NIPT was recommended for the screening of pathogenic chromosome microdeletion/duplication, and NIPT combining with other screening methods further improved the screening performance for pathogenic fetal CNV.

Prenatal diagnosis of partial monosomy 8p (8p23.2→pter) and partial trisomy 15q (15q21.2→qter) and incidental detection of a familial chromosome translocation of paternal origin in a pregnancy associated with increased nuchal translucency and an abnormal maternal serum screening result.

OBJECTIVE: We present partial monosomy 8p (8p23.2→pter) and partial trisomy 15q (15q21.2→qter) and incidental detection of a familial chromosome translocation of paternal origin in a pregnancy associated with increased nuchal translucency (NT) and an abnormal maternal serum screening result. CASE REPORT: A 29-year-old primigravid woman underwent chorionic villus sampling (CVS) at 13 weeks of gestation because of an increased NT thickness of 3.2 mm at 12 weeks of gestation and an abnormal maternal serum screening for Down syndrome result with a calculated risk of 1/29. Her husband was 33 years old, and there was no family history of congenital malformations. CVS revealed a derived chromosome 8 or der(8). Cytogenetic analysis of the parents revealed a karyotype of 46,XY,t(8;15)(p21.3;q13) in the father and a karyotype of 46,XX in the mother. The CVS result was 46,XY,der(8)t(8;15)(p21.3;q13)pat. The woman requested for amniocentesis at 16 weeks of gestation. Array comparative genomic hybridization (aCGH) analysis on the DNA extracted from uncultured amniocytes revealed a result of arr 8p23.3p23.2 (191,530-2,625,470) × 1.0, arr 15q21.2q26.3 (50,903,432-102,338,129) × 3.0 with a 2.434-Mb deletion of 8p23.3-p23.2 including DLGAP2, CLN8 and ARHGEF10, and a 51.435-Mb duplication of 15q21.2-q26.3 including CYP19A1 and IGF1R. Conventional cytogenetic analysis of cultured amniocytes revealed the result of 46,XY,der(8) t(8;15)(p23.2;q21.2)pat in the fetus. The pregnancy was subsequently terminated, and a malformed fetus was delivered with characteristic craniofacial dysmorphism. CONCLUSION: Maternal serum screening and NT screening may incidentally detect familial unbalanced reciprocal translocations, and aCGH analysis is useful for a precise determination of the breakpoints of the translocation and the involvement of the related genes under such a circumstance.

First trimester screening with biochemical markers and ultrasound in relation to non-invasive prenatal testing (NIPT).

Non-invasive prenatal testing (NIPT) is often erroneously received as a diagnostic procedure due to its high discriminatory power in the field of fetal trisomy 21 diagnosis (wording: "NIPT replaces amniocentesis"). Already a look at the methodology of NIPT (statistical gene dose comparison of a primarily maternofetal DNA mixture information at selected sites of the genome) easily reveals that NIPT cannot match the gold standard offered by cytogenetic and molecular genetic analysis procedures from the matrix of the entire human genome (origin: vital fetal cells), neither in diagnostic breadth nor in diagnostic depth. In fact, NIPT in fetal medicine in its current stage of development is a selective genetic search procedure, which can be applied in primary (without indication) or secondary (indication-related) screening. Thus, NIPT competes with established search procedures for this field. Here, the combined nuchal translucency (NT) test according to Nicolaides has become the worldwide standard since 2000. The strength of this procedure is its broad predictive power: NT addresses not only the area of genetics, but also the statistically 10 times more frequent structural fetal defects. Thus, NIPT and NT have large overlaps with each other in the field of classical cytogenetics, with slightly different weighting in the fine consideration. However, NIPT without a systematic accompanying ultrasound examination would mean a step back to the prenatal care level of the 1980s. In this respect, additional fine ultrasound should always be required in the professional application of NIPT. NIPT can thus complement NT in wide areas, but not completely replace it.

Association of Elevated Maternal Serum Total Bile Acids With Low Birth Weight and Intrauterine Fetal Growth Restriction.

Importance: Bile acids play essential roles in metabolic modulation. Excessive serum total bile acid (sTBA) levels during pregnancy are associated with adverse perinatal outcomes; however, their association with the risk of intrauterine growth restriction (IUGR) remains unclear. Objective: To investigate the association between maternal sTBA concentration during pregnancy and the risk of IUGR. Design, Setting, and Participants: This retrospective cohort study included pregnant individuals who delivered live singleton neonates and had regular antenatal examination records available at a hospital-based center in Shanghai, China, from 2014 to 2018. Data were analyzed from July to November 2020. Exposures: Maternal sTBA concentration during pregnancy. Main Outcomes and Measures: Fetal birth weight and probability of low birth weight (LBW) and IUGR. Results: This study included 68 245 singleton pregnancies with live births for analysis. The mean (SD) age of the pregnant individuals was 30.5 (3.8) years, 67 168 patients (98.4%) were Han, and 50 155 (73.5%) were nulliparous. Nonlinear regression models suggested that there was an inverted J-shaped association between maternal sTBA level during pregnancy and fetal birth weight, with a steep decrease in birth weight at high sTBA levels (estimated mean [SE] birth weight for sTBA of 40.8 ug/mL, 2879 [39.9] g) and greater birth weights at lower sTBA levels (estimated mean [SE] birth weight for sTBA 0.4 µg/mL, 3290 [3.9] g; and for 4.1 µg/mL, 3334 [1.6] g). Lower birth weight and a higher incidence of IUGR were observed in patients with gestational hypercholanemia (sTBA ≥4.08 µg/mL) compared with those without gestational hypercholanemia (birth weight: estimated adjusted mean [SE], 3309 [3.32] vs 3338 [0.80] g; P = .005; incidence of IUGR: 62 of 4467 [1.4%] vs 312 of 63 778 [0.5%]; P < .001). Moreover, compared with patients with sTBA concentrations of less than 4.08 µg/mL, those with gestational hypercholanemia had an increased risk of LBW (adjusted odds ratio [aOR], 1.29; 95% CI, 1.09-1.53) and IUGR (aOR, 2.18; 95% CI, 1.62-2.91). In addition, there was an additive interaction between hypertensive disorders in pregnancy (HDP) and hypercholanemia on LBW and IUGR risk. The highest risks of LBW and IUGR were found in pregnant individuals with both HDP and hypercholanemia compared with those with normotensive pregnancies with sTBA concentrations less than 4.08 µg/mL (LBW: aOR, 9.13; 95% CI, 6.88-12.12; IUGR: aOR, 19.14; 95% CI, 12.09-30.28). Conclusions and Relevance: This study found that gestational hypercholanemia was associated with an increased risk of LBW and IUGR, especially in pregnant individuals with HDP. Therefore, it would be meaningful to monitor sTBA concentration during the follow-up of pregnancies with potential IUGR.

Predictability of Macrosomic Birth based on Maternal Factors and Fetal Aneuploidy Screening Biochemical Markers in Hyperglycemic Mothers.

Background: Macrosomic birth weight has been implicated as a significant risk factor for developing various adult metabolic diseases such as diabetes mellitus and coronary heart diseases; it has also been associated with higher incidences of complicated births. This study aimed to examine the predictability of macrosomic births in hyperglycemic pregnant women using maternal clinical characteristics and serum biomarkers of aneuploidy screening performed in the first half of pregnancy. Methods: A retrospective observational study was performed on a cohort of 1,668 pregnant women who 1) had positive outcomes after undergoing 50-g oral glucose challenge test (OGCT) at two university-based hospitals and 2) underwent any one of the following maternal biomarker screening tests for fetal aneuploidy: triple test, quadruple test, and integrated test. Logistic regression-based models for predicting macrosomic births using maternal characteristics and serum biomarkers were developed and evaluated for prediction power. A nomogram, which is a graphical display of the best predictable model, was then generated. Results: The study cohort included 157 macrosomic birth cases defined as birth weight ≥3,820 g, which was equivalent to the top 10 percentile of the modeling cohort. Three primary models solely based on serum biomarkers achieved area under curves (AUCs) of 0.55-0.62. Expanded models, including maternal demographic and clinical factors, demonstrated an improved performance by 25% (AUCs, 0.69-0.73). Conclusion: Our prediction models will help to identify pregnancies with an elevated risk of macrosomic births in hyperglycemic mothers using maternal clinical factors and serum markers from routine antenatal screening tests. Prediction of macrosomic birth at mid-pregnancy may allow customized antenatal care to reduce the risk of macrosomic births.

Performance of a targeted cell-free DNA prenatal test for 22q11.2 deletion in a large clinical cohort.

OBJECTIVE: 22q11.2 deletion is more common than trisomies 18 and 13 combined, yet no routine approach to prenatal screening for this microdeletion has been established. This study evaluated the clinical sensitivity and specificity of a targeted cell-free DNA (cfDNA) test to screen for fetal 22q11.2 deletion in a large cohort, using blinded analysis of prospectively enrolled pregnancies and stored clinical samples. METHODS: In order to ensure that the analysis included a meaningful number of cases with fetal 22q11.2 deletion, maternal plasma samples were obtained by prospective, multicenter enrolment of pregnancies with a fetal cardiac abnormality and from stored clinical samples from a research sample bank. Fetal genetic status, as evaluated by microarray analysis, karyotyping with fluorescence in-situ hybridization or a comparable test, was available for all cases. Samples were processed as described previously for the Harmony prenatal test, with the addition of DANSR (Digital Analysis of Selected Regions) assays targeting the 3.0-Mb region of 22q11.2 associated with 22q11.2 deletion syndrome. Operators were blinded to fetal genetic status. Sensitivity and specificity of the cfDNA test for 22q11.2 deletion were calculated based on concordance between the cfDNA result and fetal genotype. RESULTS: The final study group consisted of 735 clinical samples, including 358 from prospectively enrolled pregnancies and 377 stored clinical samples. Of 46 maternal plasma samples from pregnancies with a 22q11.2 deletion, ranging in size from 1.25 to 3.25 Mb, 32 had a cfDNA result indicating a high probability of 22q11.2 deletion (sensitivity, 69.6% (95% CI, 55.2-80.9%)). All 689 maternal plasma samples without a 22q11.2 deletion were classified correctly by the cfDNA test as having no evidence of a 22q11.2 deletion (specificity, 100% (95% CI, 99.5-100%)). CONCLUSIONS: The results of this large-scale prospective clinical evaluation of the sensitivity and specificity of a targeted cfDNA test for fetal 22q11.2 deletion demonstrate that this test can detect the common and smaller, nested 22q11.2 deletions with a low (0-0.5%) false-positive rate. Although the positive predictive value (PPV) observed in this study population was 100%, the expected PPV in the general pregnant population is estimated to be 12.2% at 99.5% specificity and 41.1% at 99.9% specificity. The use of this cfDNA test to screen for 22q11.2 deletion could enhance identification of pregnancies at risk for 22q11.2 deletion syndrome without significantly increasing the likelihood of maternal anxiety and unnecessary invasive procedures related to a false-positive result. © 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Society for Maternal-Fetal Medicine Consult Series #57: Evaluation and management of isolated soft ultrasound markers for aneuploidy in the second trimester: (Replaces Consults #10, Single umbilical artery, October 2010; #16, Isolated echogenic bowel diagnosed on second-trimester ultrasound, August 2011; #17, Evaluation and management of isolated renal pelviectasis on second-trimester ultrasound, December 2011; #25, Isolated fetal choroid plexus cysts, April 2013; #27, Isolated echogenic intracardiac focus, August 2013).

Soft markers were originally introduced to prenatal ultrasonography to improve the detection of trisomy 21 over that achievable with age-based and serum screening strategies. As prenatal genetic screening strategies have greatly evolved in the last 2 decades, the relative importance of soft markers has shifted. The purpose of this document is to discuss the recommended evaluation and management of isolated soft markers in the context of current maternal serum screening and cell-free DNA screening options. In this document, "isolated" is used to describe a soft marker that has been identified in the absence of any fetal structural anomaly, growth restriction, or additional soft marker following a detailed obstetrical ultrasound examination. In this document, "serum screening methods" refers to all maternal screening strategies, including first-trimester screen, integrated screen, sequential screen, contingent screen, or quad screen. The Society for Maternal-Fetal Medicine recommends the following approach to the evaluation and management of isolated soft markers: (1) we do not recommend diagnostic testing for aneuploidy solely for the evaluation of an isolated soft marker following a negative serum or cell-free DNA screening result (GRADE 1B); (2) for pregnant people with no previous aneuploidy screening and isolated echogenic intracardiac focus, echogenic bowel, urinary tract dilation, or shortened humerus, femur, or both, we recommend counseling to estimate the probability of trisomy 21 and a discussion of options for noninvasive aneuploidy screening with cell-free DNA or quad screen if cell-free DNA is unavailable or cost-prohibitive (GRADE 1B); (3) for pregnant people with no previous aneuploidy screening and isolated thickened nuchal fold or isolated absent or hypoplastic nasal bone, we recommend counseling to estimate the probability of trisomy 21 and a discussion of options for noninvasive aneuploidy screening through cell-free DNA or quad screen if cell-free DNA is unavailable or cost-prohibitive or diagnostic testing via amniocentesis, depending on clinical circumstances and patient preference (GRADE 1B); (4) for pregnant people with no previous aneuploidy screening and isolated choroid plexus cysts, we recommend counseling to estimate the probability of trisomy 18 and a discussion of options for noninvasive aneuploidy screening with cell-free DNA or quad screen if cell-free DNA is unavailable or cost-prohibitive (GRADE 1C); (5) for pregnant people with negative serum or cell-free DNA screening results and an isolated echogenic intracardiac focus, we recommend no further evaluation as this finding is a normal variant of no clinical importance with no indication for fetal echocardiography, follow-up ultrasound imaging, or postnatal evaluation (GRADE 1B); (6) for pregnant people with negative serum or cell-free DNA screening results and isolated fetal echogenic bowel, urinary tract dilation, or shortened humerus, femur, or both, we recommend no further aneuploidy evaluation (GRADE 1B); (7) for pregnant people with negative serum screening results and isolated thickened nuchal fold or absent or hypoplastic nasal bone, we recommend counseling to estimate the probability of trisomy 21 and discussion of options for no further aneuploidy evaluation, noninvasive aneuploidy screening through cell-free DNA, or diagnostic testing via amniocentesis, depending on clinical circumstances and patient preference (GRADE 1B); (8) for pregnant people with negative cell-free DNA screening results and isolated thickened nuchal fold or absent or hypoplastic nasal bone, we recommend no further aneuploidy evaluation (GRADE 1B); (9) for pregnant people with negative serum or cell-free DNA screening results and isolated choroid plexus cysts, we recommend no further aneuploidy evaluation, as this finding is a normal variant of no clinical importance with no indication for follow-up ultrasound imaging or postnatal evaluation (GRADE 1C); (10) for fetuses with isolated echogenic bowel, we recommend an evaluation for cystic fibrosis and fetal cytomegalovirus infection and a third-trimester ultrasound examination for reassessment and evaluation of growth (GRADE 1C); (11) for fetuses with an isolated single umbilical artery, we recommend no additional evaluation for aneuploidy, regardless of whether results of previous aneuploidy screening were low risk or testing was declined. We recommend a third-trimester ultrasound examination to evaluate growth and consideration of weekly antenatal fetal surveillance beginning at 36 0/7 weeks of gestation (GRADE 1C); (12) for fetuses with isolated urinary tract dilation A1, we recommend an ultrasound examination at ≥32 weeks of gestation to determine if postnatal pediatric urology or nephrology follow-up is needed. For fetuses with urinary tract dilation A2-3, we recommend an individualized follow-up ultrasound assessment with planned postnatal follow-up (GRADE 1C); (13) for fetuses with isolated shortened humerus, femur, or both, we recommend a third-trimester ultrasound examination for reassessment and evaluation of growth (GRADE 1C).

Secondary prevention of congenital cytomegalovirus infection with valacyclovir following maternal primary infection in early pregnancy.

OBJECTIVE: Cytomegalovirus (CMV) maternal primary infection (MPI) in early pregnancy is the main risk factor for congenital CMV (cCMV) infection with long-term sequelae. Our aim was to evaluate, in a single center offering CMV serology screening at 11-14 gestational weeks, secondary prevention of cCMV by administration of high-dosage maternal oral valacyclovir (VACV) in the first trimester of pregnancy. METHODS: This was a case-control study in a longitudinal cohort of pregnancies with CMV-MPI diagnosed prior to 14 weeks of gestation by serology screening (immunoglobulin (Ig) M and IgG measurement and IgG avidity) between 2009 and 2020. From October 2019 onwards, all women presenting at our center with MPI before 14 weeks' gestation were offered treatment with high-dosage oral VACV (8 g/day, 4 g twice/day). We used propensity score matching to compare fetal infection rates in cases treated with maternal oral VACV (8 g/day) with those in untreated controls. Fetal infection was assessed following amniocentesis at 17-22 weeks of gestation, by polymerase chain reaction (PCR) analysis of amniotic fluid for viral DNA. RESULTS: Of 310 cases of CMV-MPI identified, 269 underwent amniocentesis for PCR. Of these, 66 were offered, and 65 accepted, treatment with VACV. From the remaining untreated cases, we selected 65 controls, matched for proportion of periconceptional infections and gestational age at amniocentesis. VACV was initiated at a median gestational age of 12.71 (interquartile range (IQR), 10.00-13.86) weeks and the median duration of treatment was 35 (IQR, 26-54) days. On multivariate logistic regression, fetal infection was lower in the treated group (odds ratio, 0.318 (95% CI, 0.120-0.841); P = 0.021). One treated patient developed acute renal failure 4 weeks after initiation of VACV therapy, but this resolved within 5 days after treatment was stopped. CONCLUSION: This study confirms the acceptability, tolerance and benefit of secondary prevention by VACV of cCMV infection in a clinical setting with a well-established routine maternal serum screening policy in the first trimester of pregnancy. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Early pregnancy prediction of spontaneous preterm birth before 32 completed weeks of pregnancy using plasma RNA: transcriptome discovery and initial validation of an RNA panel of markers.

OBJECTIVE: To compare the second-trimester plasma cell-free (PCF) transcriptome of women who delivered at term with that of women with spontaneous preterm birth (sPTB) at or before 32 weeks of gestation and identify/validate PCF RNA markers present by 16 weeks of gestation. DESIGN: Prospective case-control study. SETTING: Academic tertiary care centre. POPULATION: Pregnant women with known outcomes prospectively sampled. METHODS: PCF RNAs extracted from women at 22-24 weeks of gestation (five sPTB up to 32 weeks and five at term) were hybridised to gene expression arrays. Differentially regulated RNAs for sPTB up to 32 weeks were initially selected based on P value compared with control (P < 0.01) and fold change (≥1.5×). Potential markers were then reordered by narrowness of distribution. Final marker selection was made by searching the Metacore™ database to determine whether the PCF RNAs interacted with a reported set of myometrial Preterm Initiator genes. RNAs were confirmed by quantitative reverse transcription polymerase chain reaction and tested in a second group of 40 women: 20 with sPTB up to 32 weeks (mean gestation 26.5 weeks, standard deviation ±2.6 weeks), 20 with spontaneous term delivery (40.1 ± 0.9 weeks) sampled at 16-19+5  weeks of gestation. MAIN OUTCOME MEASURE: Identification of PCF RNAs predictive of sPTB up to 32 weeks. RESULTS: Two hundred and ninety-seven PCR RNAs were differentially expressed in sPTB up to 32 weeks of gestation. Further selection retained 99 RNAs (86 mRNAs and 13 microRNAs) and five of these interacted in silica with seven Preterm Initiator genes. Four of five RNAs were confirmed and tested on the validation group. The expression of each confirmed PCF RNA was significantly higher in sPTB up to 32 weeks of gestation. In vitro study of the four mRNAs revealed higher expression in placentas of women with sPTB up to 32 weeks and the potential to interfere with myometrial quiescence. CONCLUSIONS: The PCF RNA markers are highly associated with sPTB up to 32 weeks by 16 weeks of gestation. TWEETABLE ABSTRACT: Women destined for spontaneous preterm birth can be identified by 16 weeks of gestation with a panel of maternal plasma RNAs.