Objectives: To describe our screening population and audit of the performance of first-trimester screening for Down syndrome, based on a combined test, enhanced with additional ultrasound markers, over the whole period of the study. Material and methods:We performed a prospective study from 2009 to 2016, which included 1358 singleton fetuses with a crown-rump length of 45-84 mm. The risk of aneuploidy was calculated using nuchal translucency, fetal heart rate (FHR), and additional markers, such as nasal bone (NB), tricuspid flow (TF) and ductus venosus (DV), combined with maternal serum free β-human chorionic gonadotropin (fβ-hCG) and pregnancy-associated plasma protein-A (PAPP-A).Results: 87% of patients were evaluated using all the additional ultrasound markers and 97% of patients were assessed using at least two markers, in any combination. 70.5% of patients were also evaluated using maternal serum biochemistry. The most common risk calculation used nuchal translucency, FHR, all additional ultrasound markers, fβ-hCG and PAPP-A in 851 (62.7%) of cases. The adjusted risk of trisomy 21 was greater than 1:100 in 65 (4.8%) women. Of these patients, 58 (87.7%) chose to have an invasive test. There were 24 aneuploid fetuses (1.7%); and from these we identified 12 (50%) trisomy 21, 6 (25%) sex chromosome anomalies, with the remainder being triploidy and trisomy 18/13. The combined test detected 11 of the 12 cases as having trisomy 21, with a first trimester detection rate of 91.7%. 39 fetuses (2.8%) had various types of structural anomalies. Conclusion:The combined test enhanced with all additional ultrasound markers did not show any substantial improvement in T21 detection rate, when compared with using only one of the additional markers.

Methods: On 3rd June 2016 Embase and PubMed databases were systematically searched for all relevant articles on prevalence of pathogenic submicroscopic CNVs in fetuses tested due to advanced maternal age or parental anxiety. Relevant full text articles were analysed and based on the extracted data the prevalence of submicroscopic CNVs was calculated. Results: Meta-analysis was conducted in a pooled cohort of 10,614 fetuses based on the 10 largest studies (N > 300) of a total of 19 relevant studies. In 0.84%, 95%CI [0.55%, 1.30%] of fetuses a submicroscopic pathogenic aberration was detected prenatally. The onset/penetrance of the submicroscopic findings was studied in 10,314 fetuses out of 8 papers that presented aberrant cases with all necessary details. The prevalence of early onset syndromic disorders due to a submicroscopic aberration was calculated to be 1:270, based on 0.37%, 95%CI [0.27%, 0.52%] cases where aberrations were specified.Conclusions: This systematic review shows that a significant proportion of fetuses in a general pregnant population carry a submicroscopic pathogenic CNV. Based on these figures all women should be informed on their individual risk for all pathogenic chromosome aberrations and not only for common trisomies. P16.05The influence of chromosomal microarray and NIPT on the diagnostic yield in 6,811 high-risk pregnancies without ultrasound anomalies Objectives: Prenatal diagnostics has been impacted by technological changes in the past decade, which have affected the diagnostic yield. The aim of this study was to evaluate the impact of SNP array and non-invasive prenatal testing (NIPT) on the diagnostic yield and the number of invasive tests in our centre. Methods: The frequency of pathogenic fetal unbalanced chromosome aberrations was studied in 6811 high risk pregnancies without ultrasound anomalies referred for prenatal testing in 2009-2015 due to advanced maternal age, abnormal first trimester screening results (with nuchal translucency < 3.5mm) or recurrence risk for chromosome aberration. Chromosomal SNP microarray analysis replaced karyotyping in 2012 and since 2014 a choice between NIPT and diagnostic testing with microarray was offered to women with an increased risk for common aneuploidy (as a part of a national TRIDENT study). Results: The introduction of microarray led to an additional yield of submicroscopic pathogenic chromosome aberrations in 1.9% in fetuses without ultrasound anomalies. The introduction of NIPT led to a decrease of invasive tests, but also of the diagnostic yield. Conclusions: Since 33% of pathogenic fetal chromosome aberrations were different from the common aneuploidies and triploidy, whole genome analysis should be offered after invasive sampling. Because NIPT (as a second screening) has resulted in a decreased diagnostic yield it should be accompanied by an appropriate pre-test counselling in high risk pregnancies. Objectives: To examine whether combining the dichotomous assessment of the a-wave and the Ductus venosus (DV) PIV measurement improv...

Objectives:The study aim was to assess the early pre-eclampsia (<34 weeks) risk distribution, computed for 1290 patients with single pregnancy at 11-13 + 6 gestational weeks, as well as the prediction algorithm efficiency for a threshold value of 1 in 100. Methods: The pre-eclampsia risk was calculated using the competitive risk model developed by the Fetal Medicine Foundation, starting from an a priori risk based on history and maternal characteristics. Basal risk was adjusted according to maternal blood pressure, pulse rate index of uterine arteries and protein A associated with pregnancy, resulting a final risk. We used a program developed in Matlab. Evolution of pregnancy, respectively the development of pre-eclampsia and was evaluated retrospectively after birth. Results: 101 (9.7%) cases had a risk greater than 1 in 100 to develop early pre-eclampsia. The detection rate of pre-eclampsia was 84%. Conclusions: The model developed by FMF for prediction of pre-eclampsia is a robust protocol, with 10% of patients eligible for Aspirin prophylaxis. The detection rate is similar to that in model development studies, but is already influenced by Aspirin prophylaxis in the high-risk group. P15.02Three-dimensional power Doppler ultrasound evaluation of the orbital vascularities in pre-eclampsia

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