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Prenatal Diagnosis and Screening for Aneuploidy
Published in Vincenzo Berghella, Obstetric Evidence Based Guidelines, 2022
Sarah Harris, Angie Jelin, Neeta Vora
CVS is typically performed between 10 and 13 weeks’ gestation. The procedure should not be completed prior to 10 weeks, due to an unacceptably high incidence of limb deficiencies. The chorionic villi are sampled using ultrasound guidance and a special catheter to aspirate a sample of the placental cells. The placenta can be accessed through either a transcervical or transabdominal approach. There are no significant differences in pregnancy loss between transabdominal and transcervical CVS, with significant heterogeneity between studies [30, 41].
Approach to women with a previous child with a genetic disorder
Published in Minakshi Rohilla, Recurrent Pregnancy Loss and Adverse Natal Outcomes, 2020
A tiny sample of tissue is taken from the placenta to perform CVS. The same genetic makeup of the child can be found in the cells on the tissue. To obtain the sample, a small tube can be inserted through the woman's vagina and cervix (transcervical CVS) or a thin needle can be inserted through the abdomen and wall of the uterus (transabdominal CVS).
What Genetic Screening Is Appropriate in Recurrent Pregnancy Loss?
Published in Howard J.A. Carp, Recurrent Pregnancy Loss, 2020
The limit of sensitivity of invasive prenatal diagnosis in detecting chromosomal abnormalities is 5–10 Mb using conventional karyotyping and 3 Mb with comparative genomic hybridization. In contrast, molecular karyotyping using a chromosomal microarray enables the detection of submicroscopic changes or copy-number variants (CNVs) except where there is a balanced rearrangement. In the last two decades, considerable experience has accumulated using this technique to identify CNVs in adults and children presenting with intellectual impairment or dysmorphic features. The same approach can now be used for CVS and amniocentesis samples.
Noninvasive prenatal testing of beta-thalassemia for common Pakistani mutations: a comparative study using cell-free fetal DNA from maternal plasma and chorionic villus sampling
Published in Hematology, 2022
Muhammad Afzal, Muhammad Abdul Naeem, Suhaib Ahmed, Nayyar Amin, Amena Rahim, Manazza Munawar, Mansoor Ishaq, Ali Rathore, K. Maria
Prenatal genetic testing for pregnant women is being done to diagnose the thalassemia in the fetus, where both partners are thalassemia carriers. This genetic test is usually done by routine chorionic villus sampling (CVS) and amniocentesis where a tiny piece of the placenta and a fluid that surrounds the fetus are taken, respectively. Both CVS and amniocentesis are invasive procedures for fetal sampling, and chances of miscarriage are 1/200–400 and 1/100–200, respectively [4] with a 98–99% accuracy rate [5]. Due to the lack of effective treatment, beta-thalassemia is putting a major financial and psychological adverse effect on parents, society, and increasing patient burden on the national health system. Up to now, prevention is the best gold standard way to reduce this genetic disorder. A couple where both partners are having beta-thalassemia carrier is advised to the prenatal screening of fetus usually on 10–12 weeks of pregnancy and opt to terminate the pregnancy in case of an affected fetus. To address this issue, invasive prenatal testing (IPT) was initiated for the first time in Pakistan by Ahmed et al. in 1994 [6].
Current understanding of the etiology of cyclic vomiting syndrome and therapeutic strategies in its management
Published in Expert Review of Clinical Pharmacology, 2022
Rosita Frazier, Thangam Venkatesan
CVS, like other DGBI, is associated with multiple comorbid conditions, such as migraine, anxiety, depression, and autonomic dysfunction [13–15]. This can adversely affect patients, and therapy should be directed at both CVS and other comorbidities to improve overall patient outcomes. CVS imposes a significant burden on patients, families, and the health-care system [16]. A subset of patients are often hospitalized and visit the emergency department (ED) due to recalcitrant symptoms. However, care in the ED setting is often inconsistent and patchy, and patients are stigmatized and labeled as ‘drug users’ and denied standard care. This results in a poor patient experience and worse outcomes [17]. Patients with CVS also undergo extensive and futile investigations, and ~20% even undergo surgeries such as cholecystectomy and/or a hysterectomy [13,17]. Approximately 30% of the patients are disabled due to their disorder and suffer from several socioeconomic consequences, such as loss of job, delay in higher education, and disruption of the family unit [18]. The economic impact of CVS is significant, and one study showed that the cost due to hospitalizations alone amounted to $ 200 million in 1 year. This did not include the cost of ED visits, procedures, and indirect costs due to absenteeism and workdays lost [17]. In summary, CVS is common and disabling, and efforts to understand the pathophysiology and develop new treatments are critical [19].
Celocentesis for Early Prenatal Diagnosis in Couples at-Risk for β-Thalassemia and Sicilian (δβ)0-Thalassemia
Published in Hemoglobin, 2022
Antonino Giambona, Filippo Leto, Filippo Cassarà, Viviana Tartaglia, Rosario Campisi, Corrado Campisi, Valentina Cigna, Elena Mugavero, Gaspare Cucinella, Emanuela Orlandi, Francesco Picciotto, Aurelio Maggio, Margherita Vinciguerra
In recent years, the number of women requiring this procedure has increased. This is due to the early availability of the test, rather than other procedures, at least 4 weeks earlier than CVS. In Italy, it is possible to undergo a VIP before the 12th week of gestation, in the case of an affected fetus. After this week, it will be necessary to resort to a medically assisted therapeutic procedure, which can cause a worrying psycho-emotional condition for the mother, as this is more traumatic than in the first trimester VIP. Furthermore, celocentesis could be indicated for earlier PND in a population with restrictive laws on abortion such as Islamic and Orthodox Jewish populations. As reported by Makrydimas et al. [31], the risk of miscarriages associated with celocentesis in a consecutive series of 307 singletons in an ongoing pregnancy was 2.3% at 7–40 d. However, it should not be overlooked that the reported risk of spontaneous fetal loss after 4–6 weeks of gestation is 15.0–20.0%, and at 10–13 weeks it decreases to 2.8% [32–34]. Given the high rate of feasibility, diagnostic reliability, the low risk of a miscarriage, together with the acceptability of the procedure, in the future, it might be possible to propose celocentesis to at-risk couples for early PND of monogenic diseases using the optimized laboratory workflow proposed [30].