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(Abstracted from Prenat Diagn2020;40:785–791)Skeletal dysplasia can be difficult to diagnose on prenatal sonogram because of phenotypic overlap between conditions. Two of the more common skeletal dysplasias, achondroplasia and thanatophoric dysplasia (TD), occur because of mutations in the FGFR3gene.

(Abstracted from Prenat Diagn2019;39:818–829)Investigation after birth of fetal anomalies detected on prenatal ultrasound (US) is important, particularly after termination of pregnancy or fetal or perinatal loss, in terms of significant implications for genetic counseling, subsequent reproductive choices, and other family members. Confirmation of perinatal findings can traditionally be confirmed at a perinatal autopsy, but only 40% of parents consent to this procedure.

(Abstracted from Lancet2019;393:747–757)Fetal structural anomalies, detected by ultrasonography, have a range of genetic causes, including chromosomal aneuploidy, copy number variations (CNVs), and pathogenic sequence variants in developmental genes. Conventional prenatal cytogenetic analysis was historically the first-line method to investigate these anomalies, but chromosomal microarray analysis has been adopted more recently, as this test is able to detect smaller, but significant, CNVs.

(Abstracted from Genet Med2018;20(11):1430–1437)Unexpected fetal abnormalities occur in 2% to 5% of pregnancies. Although traditional cytogenetic and microarray approaches achieve diagnosis in approximately 40% of cases, lack of diagnosis in others impedes parental counseling, informed decision making, and pregnancy management.

(Abstracted from BMJ2016;354:i3426)Noninvasive prenatal testing, also known as cell-free DNA (cfDNA) screening, is an efficient screening test for Down syndrome with roughly 99% sensitivity and false-positive rates of less than 0.1% in both high-risk and general populations. This study aimed to examine the potential costs and consequences of introducing cfDNA screening in the public sector Down syndrome screening pathway as an additional screening test dependent on the risk generated by current screening.

Obstet Gynecol Surv 2016;71(4):211–213Since 2011, the use of massively parallel sequencing of cell-free DNA (cfDNA) in maternal plasma for noninvasive prenatal testing (NIPT) of fetal aneuploidies has become available in more than 60 countries.

Obstet Gynecol Surv 2016;71(1):13–15Cystic fibrosis (CF) is a severe, autosomal recessive, multisystem condition affecting the respiratory and digestive systems. It is caused by mutations in the CF transmembrane conductance regulator (CFTR) gene.

The RhD (RH1) antigen of the rhesus system is the most commonly implicated antigen for hemolytic disease of the fetus. Postnatal prophylaxis with anti-RhD immunoglobulin in RhD−women with an RhDchild has been shown to reduce the risk of becoming alloimmunized. Subsequent introduction of routine antenatal prophylaxis with anti-RhD immunoglobulin in the third trimester for all RhD−women is now standard in many countries. Cell-free fetal DNA in maternal plasma can be tested for the presence or absence of the RHDgene, essentially screening for fetal Rh status. This prospective, multicenter cohort study was performed to determine the diagnostic accuracy of RHDgenotyping in RhD−parturients and the optimal gestation for implementation into practice.

The National Screening Committee in the United Kingdom recommends that all pregnant women be offered a screening test for Down syndrome. Women who have a high-risk result are then offered chorionic villus sampling or amniocentesis, but these invasive tests carry a risk of miscarriage and cannot be performed until 10 weeks of gestation. Validity studies have assessed the technology for noninvasive prenatal diagnosis (NIPD) for Down syndrome. An NIPD test using cell-free fetal DNA eliminates the risk of miscarriage associated with invasive testing. Other attributes of NIPD included its accuracy and timing in pregnancy because it can be performed somewhat earlier than invasive tests. Another important difference between NIPD and invasive tests is the fact that NIPD provides targeted information (trisomy 21 only or trisomies 21, 18, and 13 only) as compared with an invasive test where information on all chromosomes can be provided. Understanding which attributes are most highly valued by patients and health professionals will help guide the implementation of NIPD. Discrete choice experiments are used to examine stakeholder preferences, in which hypothetical health care options are presented and participants are asked to choose between them. This study was designed to compare the preferences of women and health professionals for key attributes of diagnostic tests for Down syndrome, considering possible clinical features of NIPD relative to invasive tests.

More than 10 years ago, conventional whole-body MRI at 1.5 Tesla (T) was proposed as a more rapid, less invasive alternative to conventional invasive perinatal autopsy. However, there is poor agreement between the perinatal autopsy findings and the postmortem MRI at 1.5 T. Studies in small animals have shown that good images of anatomy can be obtained using high-field MRI at 9.4 T and have led to the present investigation. This prospective blinded study compared the diagnostic accuracy of high-field MRI at 9.4 T and conventional MRI for postmortem examination of small human fetuses. A total of 18 fetuses of less than 22 weeks’ gestation were examined using 3-dimensional T2-weighted fast-spin echo sequences for whole-body MRI with 1.5 T and 9.4 T scanners before invasive autopsy. The MRI images for each system were compared to the invasive autopsy findings by investigators who were blinded to the MRI settings. Tissue contrast in 14 different regions for MRI images at 1.5 T and 9.4 T was compared separately and in a random order. The quality of the MRI images was rated on a 4-point scale.

(Abstracted from Prenat Diagn2017;37:1281–1290)Noninvasive prenatal testing (NIPT) for aneuploidy using cell-free DNA (cfDNA) has become widely available and popular for detection of Down syndrome (DS) because of its high sensitivity (99%) and specificity (99.5%). The acceptance of NIPT as an alternative to the first-trimester combined test has greatly reduced the use of invasive prenatal diagnostic testing.