DEGUM, ÖGUM, SGUM and FMF Germany Recommendations for the Implementation of First-Trimester Screening, Detailed Ultrasound, Cell-Free DNA Screening and Diagnostic Procedures

Abstract

First-trimester screening between 11 + 0 and 13 + 6 weeks with qualified prenatal counseling, detailed ultrasound, biochemical markers and maternal factors has become the basis for decisions about further examinations. It detects numerous structural and genetic anomalies. The inclusion of uterine artery Doppler and PlGF screens for preeclampsia and fetal growth restriction. Low-dose aspirin significantly reduces the prevalence of severe preterm eclampsia. Cut-off values define groups of high, intermediate and low probability. Prenatal counseling uses detection and false-positive rates to work out the individual need profile and the corresponding decision: no further diagnosis/screening - cell-free DNA screening - diagnostic procedure and genetic analysis. In pre-test counseling it must be recognized that the prevalence of trisomy 21, 18 or 13 is low in younger women, as in submicroscopic anomalies in every maternal age. Even with high specificities, the positive predictive values of screening tests for rare anomalies are low. In the general population trisomies and sex chromosome aneuploidies account for approximately 70 % of anomalies recognizable by conventional genetic analysis. Screen positive results of cfDNA tests have to be proven by diagnostic procedure and genetic diagnosis. In cases of inconclusive results a higher rate of genetic anomalies is detected. Procedure-related fetal loss rates after chorionic biopsy and amniocentesis performed by experts are lower than 1 to 2 in 1000. Counseling should include the possible detection of submicroscopic anomalies by comparative genomic hybridization (array-CGH). At present, existing studies about screening for microdeletions and duplications do not provide reliable data to calculate sensitivities, false-positive rates and positive predictive values.

Noninvasive prenatal testing and maternal obesity: A review

“…Both societies recognized the increased risk of a no‐call NIPT result secondary to a lower FF in severely obese pregnant women. The German Society of Ultrasound in Medicine and Biology suggests informing patients about the higher no‐call rate for obese pregnant women and recommends primary diagnostic testing for women with a high BMI 22 …”

Isolated Echogenic Cardiac Focus: Assessing Association with Trisomy 21 by Combining Results from a Prenatal Center with a Bayesian Meta-Analysis

“…Noninvasive prenatal testing (NIPT) is able to detect placental cell-free DNA fragments in maternal blood. The NIPT test is a useful variant for clarifying patients with a medium-risk constellation [26]. The limitations of the NIPT are a lack of feasibility in 5 % of cases due to an insufficient concentration of placental DNA in the maternal plasma, as well as discordant findings between NIPT and genetic analysis by placental mosaicism [27].…”

Ultrasound in Pregnancy during the Corona-Virus Pandemic: a Practical Approach

“…Adequate first trimester screening with a focus on early assessment of the anatomy, as well as pre-eclampsia and aneuploidy screening should not be avoidedespecially with regard to planning pregnancy [18]. But here too, the question arises as to the consequence of an abnormal or inconspicuous result.…”

“…Ebenso sollte auf ein adäquates Ersttrimester-Screening mit dem Fokus auf der frühen Feindiagnostik, sowie dem Präeklampsie-und Aneuploidie-Screening nicht verzichtet werdeninsbesondere unter dem Aspekt der Planung der Schwangerschaft [18]. Aber auch hier stellt sich die Frage nach der Konsequenz eines auffälligen bzw.…”