Browsing by Author "Martins, Ana Teresa"
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- Chorionic villus sampling: 10 years of experience in a University referral centerPublication . Martins, Ana Teresa; Francisco, Carla; Correia, Hildeberto; Cohen, ÁlvaroObjectives: The purpose of this study was to estimate our center-specific CVS-related miscarriage rate. Methods: This is an observational retrospective study of women submitted to a CVS in our hospital, between January 1st, 2007 and December 31st, 2016. Maternal and pregnancy characteristics, procedure details, genetic results and pregnancy outcomes of all patients were collected. The FMF miscarriage risk algorithm was used to estimate our population expected risk of miscarriage. To establish the procedure-related risk of miscarriage, we compared the observed with the expected miscarriage rate. Results: We had a total number of 1523 women with a singleton pregnancy who did a CVS over the 10-year period. The mean maternal age was 34 years old; the majority of the women was Caucasian, multiparous and had a spontaneous pregnancy. The most common indication for CVS was a high-risk result in the 1st trimester combined screening test. The karyotype was normal in 72,7% of cases, 11,1% were T21 and 7,2% were T13 or T18. In the study group, 33 women were diagnosed with a fetal demise, 435 had a TOP and there were 4 intrauterine deaths and 34 miscarriages. The rate of miscarriage in our population was 3,2% and the expected patient specific risk for miscarriage was 3,0%. There was no statistical significance between the two miscarriage rates p = 0,705. Conclusion: In our study the risk of miscarriage in the CVS group was not significantly different from that the expected patient specific risk (3.2 % vs 3%, p = 0.7). The procedure-related risk of miscarriage was 0,2%, similar to the rates describe in the literature. An accurate risk of pregnancy loss should be used when counseling women for CVS to allow an informed decision.
- Prenatal diagnosis of Beckwith Wiedemann syndrome: a case reportPublication . Ferreira, Cristina; Tarelho, Ana; Marques, Bárbara; Serafim, Sílvia; Pedro, Sónia; Granja, Carla; Mata, Rodrigo; Martins, Ana Teresa; Carvalho, Inês; Correia, HildebertoBeckwith-Wiedemann syndrome (BWS) is the most common overgrowth disease. Phenotypically and genetically heterogeneous, it is linked with epigenetic/genetic aberrations on 11p15.4p15.5 chromosome region and the majority of cases are diagnosed after birth with prenatal diagnosis being difficult and depending on the identification of specific ultrasound (US) anomalies. Here we present a case of a fetus from a healthy 21-year-old primiparous woman, with a low risk in the first trimester aneuploidy screening and bilaterally increase in renal volume detected in the second trimester US. An amniotic fluid (AF) sample was collected at 24 weeks. Rapid aneuploidy diagnosis by QF-PCR and sequencing of a multigene panel for renal dysplasia were performed with a normal result for common aneuploidies and detection of a variant with uncertain significance, respectively. The pregnant was referred to a differentiated prenatal diagnosis center and a detailed US at 30 weeks and 3 days showed multiple features suggestive of BWS: macroglossia, weight estimation at P100, significantly enlarged kidneys without corticomedullary differentiation, hepatomegaly, prenasal and cervical subcutaneous thickening, and suspected cardiomegaly without structural heart disease. The methylation pattern study of 11p15 region by MS-MLPA revealed hypermethylation of H19/GF2: IG differentially methylated region (DMR), confirming the Beckwith-Wiedemann diagnosis. In contrast to postnatal cases that can be diagnosed by phenotypic scoring, prenatal diagnosis of BWS is relatively challenging because some common features cannot be detected by US and other features appear only after 30 weeks of gestation and may be missed on second-trimester morphological ultrasound. Omphalocele is the most common prenatal phenotypic BWS-associated feature, and is the first and most easily identified in prenatal screening, but there are other features that may suggest BWS such as macroglosia, macrosomia, placental mesenchymal dysplasia, polyhydramnios, and visceromegaly. Routine molecular testing of all fetuses with one or more prenatal BWS-associated features is of utmost importance, as early diagnosis is significantly beneficial for prenatal counselling, perinatal management allowing for better birth planning and postnatal care for neonatal hypoglycemia, respiratory distress, and risk of malignancy.
- Trisomy 15 mosaicism: Challenges in prenatal diagnosisPublication . Silva, Marisa; Alves, Cristina; Pedro, Sónia; Marques, Bárbara; Ferreira, Cristina; Furtado, José; Martins, Ana Teresa; Fernandes, Rosário; Correia, Joaquim; Correia, HildebertoTrisomy 15 mosaicism (mosT15) has been described in fetuses and live-born infants [Christian et al., 1996; Redaelli et al., 2005], with most cases involving confined placental mosaicism (CPM) and meiotic non-disjunction (ND) [EUCROMIC, 1999]. Poor pregnancy outcome prognosis is associated with the presence of aneuploid cells, and there is also a risk of uniparental disomy 15 (UPD15) due to correction of the trisomic state to a disomic constitution. Trisomy or monosomy rescue, gamete complementation and postfertilization error are the main mechanisms leading to UPD and may cause heterodisomy (heteroUPD), isodisomy (isoUPD) or both, depending on the number of meiotic recombinations. The result of maternal (matUPD) and paternal (patUPD) UPD15 is Prader–Willi and Angelman syndrome, respectively, due to imprinting of chromosome region 15q11–15q13. UPD detection can only be achieved using molecular methodologies, such as methylation-specific assays (MSA) [Kotzot, 2008] and, more recently, genome-wide single nucleotide polymorphism (SNP) arrays [Conlin et al., 2010; Schroeder et al., 2013]. MSA allow for methylation pattern analysis of the chromosome regions of interest and SNP-arrays may provide information about copy number as well as UPD, in cases of isoUPD or isodisomy secondary to recombination. HeteroUPD may also be diagnosed by SNParrays if parental and proband DNAs are analyzed in a trio [Conlin et al., 2010; Schroeder et al., 2013]. However, not all molecular methods are equally informative and when a mosaicism is present, especially in a prenatal setting, parent-of-origin analysis as well as karyotype–phenotype correlations become quite challenging. Here we report on a fetus with a CVS diagnosed mosT15 with different degrees of mosaicism found in different tissues and briefly discuss the challenges of prenatal diagnosis of UPD15. (...)