Impact of increased risk for fetal aneuploidy on maternal mood: a prospective longitudinal study

Prenatal Screening and Diagnosis: Time for a Paradigm Shift

Recent advances in genetics and imaging have ushered substantial breakthroughs in screening and diagnosis for chromosomal and structural abnormalities. Thus, it is imperative that health care providers caring for pregnant individuals should reexamine established practices in prenatal screening and diagnosis. In the past, screening for chromosomal abnormalities was based almost entirely on Down syndrome. Pregnant individuals aged > 35 years were considered at "high risk" or of "advanced maternal age" based on age alone; however, the advent of tests with high sensitivity for prenatal detection of chromosomal abnormalities should lead to abandoning that concept, at least from the perspective of chromosomal abnormalities. Given that first-trimester and second-trimester screenings will fail to detect between 5 and 20% of Down syndrome, in most situations, noninvasive testing with cell-free DNA should be the first-line screen for Down syndrome. The fact that over 99% of fetuses with Down syndrome will be detected prenatally with cell-free DNA gives other fetal chromosomal and structural abnormalities increasing prominence. Chromosomal microarray analysis (CMA) permits prenatal detection of several clinically important chromosomal aberrations that cannot be detected by karyotype and may exist in structurally normal fetuses with low-risk cell-free DNA screening. As such, CMA should be more readily conducted when invasive testing is performed, regardless of the presence of a structural abnormality. Isolated sonographic "soft markers" have no clinical significance in patients who have normal cell-free DNA screening, can cause unwarranted anxiety and a negative impact on pregnancy, and perhaps it is time to stop discussing them. Detailed first-trimester ultrasound allows early detection of several severe fetal anomalies and, therefore, in settings with adequately trained personnel and resources, should be used more frequently. This opinion traces the evolution of prenatal screening and diagnosis and advocates for a paradigm shift that aligns with recent developments in prenatal screening and diagnostic capabilities. KEY POINTS: · Noninvasive prenatal testing with cell-free DNA should be available to all pregnant individuals.. · Chromosomal microarray should be available to all pregnant individuals undergoing amniocentesis.. · Patients >35 years with low-risk screening are not at "high risk" for chromosomal abnormalities..

Noninvasive Prenatal Screening Based on Second-Trimester Ultrasonographic Soft Markers in Low-Risk Pregnant Women

Background: We aimed to assess the clinical application of noninvasive prenatal screening (NIPS) based on second-trimester ultrasonographic soft markers (USMs) in low-risk pregnant women. Methods: Data of pregnant women between April 2015 and December 2019 were retrospectively analyzed. Pregnant women [age at expected date of confinement (EDC) of <35 years; low risks for trisomy 21 (T21) and trisomy 18 (T18) based on maternal serum screening; presenting second-trimester USMs (7 types)] who successfully underwent NIPS and had available follow-up information were included in our study. Cases with positive NIPS results were prenatally diagnosed. All patients were followed up for 6 months to 2 years after NIPS, and their clinical outcomes were obtained. Subgroup analyses were performed according to the different USMs. Results: NIPS suggested that among a total of 10,023 cases, 37 (0.37%) were at high risk of aneuploidy, including 4 T21, 6 trisomy 13 (T13), and 27 sex chromosome abnormalities (SCA). Ten cases with aneuploidy (0.10%) were confirmed by prenatal diagnosis, consisting of two T21 and eight SCA. The eight fetuses with SCA consisted of one monosomy X, two XXY, one XXXY, one XXX, one XYY, and two mosaicisms. T21 was detected in one fetus with absent or hypoplastic nasal bone and one fetus with echogenic intracardiac focus (EICF). SCA was detected in five fetuses with EICF, two fetuses with multiple soft markers, and one fetus with echogenic bowel. The positive rate of chromosomal aneuploidy was significantly higher in fetuses with absent or hypoplastic nasal bone (6.25 vs. 0.10%, p = 0.017), echogenic bowel (3.7 vs. 0.10%, p = 0.029), and multiple soft markers (0.678 vs. 0.10%, p = 0.045) than in the total fetuses. The positive predictive values (PPVs) of NIPS in these three groups were 100%, 50%, and 100%, respectively. EICF accounted for 93.25% (9,346/10,023) of the study population, whereas the PPV of NIPS was only 20%. Conclusion: NIPS is an advanced screening test for low-risk pregnant women. In the 10,023 pregnant women sampled, SCA were more common than autosomal trisomy, and EICF was the most frequent USM but the least predictive aneuploidy. Further aneuploidy evaluation is suggested for low-risk pregnant women whose ultrasound indicates absent or hypoplastic nasal bone, echogenic bowel, or multiple soft markers. NIPS can serve as a second-line complementary screening for these women.

Comparing prenatal screening experiences of Icelandic women who received false-positive and true-negative first-trimester combined screening results in Iceland in 2012-2016

First-trimester combined screening (FTS) has been offered to all pregnant women in Iceland since 2003. Individuals with high-risk FTS results are offered an invasive test option with a ≤1% risk of fetal loss. This study gives insight into the prenatal screening and diagnosis experiences and preferences of 101 women who underwent FTS in Iceland in the years 2012-2016, comparing the experience of those who received false-positive FTS results to those who received true-negative results. Retrospective patient-reported anxiety levels at the time of receiving FTS results were significantly higher in those who received false-positive results compared to those who received true-negative results. For a subset of these participants, the anxiety lasted through pregnancy, and for a smaller subset, it lasted even longer. Non-invasive prenatal testing (NIPT) is currently not offered in Iceland, aside from the rare exceptional case. Given the extremely low false-positive rates of NIPT, we believe NIPT is worth considering as Iceland's standard first-tier screening method for trisomy 13, 18, and 21. We believe the findings of this study are beneficial not only for Iceland but also for other countries where FTS is the first-tier prenatal screening method or the only offered test. Additionally, only 21% of participants in our study reported that they had heard of NIPT, which emphasizes the need for comprehensive NIPT pretest information to be available prior to its uptake to ensure informed and autonomous decision-making.