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Mother and Embryo Cross Communication during Conception
Published in Carlos Simón, Carmen Rubio, Handbook of Genetic Diagnostic Technologies in Reproductive Medicine, 2022
Anna Idelevich, Andrea Peralta, Felipe Vilella
The process of implantation is divided into three stages: apposition, attachment (adhesion), and penetration. Implantation is initiated when the blastocyst meets the uterine wall. The first step is the release from the zone pellucida, a glycoprotein layer surrounding the plasma membrane, a process called “zona hatching.” Apposition is the loose connection between the blastocyst and the uterine epithelium. Usually, the apposition occurs in a small crypt in the endometrium, aligning the ICM with the uterine wall. Attachment is the furthest and strongest connection, when trophoblasts adhere and penetrate the endometrium, followed by invasion, embedding the embryo in the endometrium. Eventually, the syncytiotrophoblasts, the protrusions of trophoblast cells, come into contact with maternal blood and form chorionic villi, initiating the formation of the placenta [29].
Multiple Gestations
Published in Vincenzo Berghella, Maternal-Fetal Evidence Based Guidelines, 2022
Edward J. Hayes, Michelle R. Hayes
First trimester: Nuchal translucency and maternal age identify about 75–85% of trisomy 21 and 66.7% of trisomy 18 pregnancies with a 5% false-positive rate in twin gestations [34–36]. However, only nuchal translucency alone has been validated for the detection of these disorders in higher order gestations [37]. In a recent meta-analysis, first trimester combined test in twins had a pooled sensitivity of 0.893 (95% confidence interval [CI] 0.797–0.947) and a pooled specificity of 0.946 (95% CI 0.933–0.957). The performance of the test was good (summary receiver operating characteristic area under the curve: 0.817). In dichorionic twins, sensitivity and specificity were 0.862 (95% CI 0.728–0.936) and 0.952 (95% CI 0.942–0.96), respectively. In monochorionic twins, the sensitivity and specificity were 0.874% (95% CI 0.526–0.977) and 0.954% (95% CI 0.943–0.963), respectively [38]. Cell free DNA has been shown to have a pooled weighted detection rate for T21 of 98.2% (95% CI 83.2–99.8%) and false positive rate 0.05% (95 CI, 0.01–0.26%) in twins, however predictive value for T13 and T18 has yet to be determined [39].ACOG and SMFM recently endorsed cell-free DNA for the detection of T21 in twin gestations [40]. Chorionic villus sampling can be performed between 10 to 12 weeks. It has the same risks as amniocentesis in multiples [41], and has a 1.1 rate of twin-twin contamination [42].
Chorionic villus sampling
Published in Hung N. Winn, Frank A. Chervenak, Roberto Romero, Clinical Maternal-Fetal Medicine Online, 2021
Giovanni Monni, Maria Angelica Zoppi, Carolina Axiana
In 1983, Simoni et al. in Milan described a technique from first-trimester chorionic villi that could be used for direct chromosome preparation and karyotyping as well as for enzyme analyses without needing preliminary culture (17). Chorionic villi were obtained by aspiration or through biopsy from the chorion frondosum, at the edge of the placental disk. With the technique they proposed, in the freshly sampled villus, the inner cytotrophoblast layer (containing actively mitotic cells) could be separated from the outer syncytiotrophoblast cells. All analyses could be performed from these fresh whole villi.
Recurrent Second Trimester Fetal Demise Caused by Hypercoiled Umbilical Cords
Published in Fetal and Pediatric Pathology, 2023
Jonathan C Slack, Theonia K Boyd, Chrystalle Katte Carreon
Fetopsy revealed a phenotypically female, macerated fetus, approximately 14 weeks gestation by foot morphometry (foot length: 1.5 cm). Mild edema, particularly of the upper and lower extremities were observed but there were no other significant external dysmorphic features identified. With the exception of autolysis, all examined organs were appropriate for gestational age. Demise-to-delivery interval was estimated at one week based upon transmural intestinal autolysis. Examination of the fragmented umbilical cord (2 intact evaluable fragments measured 5.2 and 3 cm in length) revealed a right-twisted, linked pattern, hypercoiled cord (12 coils/10 cm) with an area of relatively more pronounced constriction at the insertion site onto the abdomen [8]. Examination of the placenta showed appropriately immature chorionic villi with global involutional changes and scattered foci of avascular villi (>15 per section) (Fig. 1).
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].
Prenatal sonographic findings in a cohort of foetuses with a confirmed 22q11.2 microdeletion at a single Chinese Tertiary Centre
Published in Journal of Obstetrics and Gynaecology, 2022
Xiang-Yi Jing, Yong-Ling Zhang, Li Zhen, Yan-Lin Li, Dong-Zhi Li
During the study period, CMA was offered as a routine prenatal test for pregnancies with the indication of foetal structural anomalies including increased nuchal translucency (NT). The mid-trimester ultrasound scan for anatomical evaluation of the foetus was conducted under the International Society of Ultrasound in Obstetrics and Gynaecology (ISUOG) Practice Guidelines (Salomon et al. 2011). Prenatal detection of congenital heart disease (CHD) was based on the ISUOG Practice Guidelines (updated) (ISUOG et al. 2013). For pregnancies with a normal sonographic scan, e.g. an abnormal serum screening result and an indication of single-gene condition, CMA was offered as an option after a normal karyotype or genotype was obtained. Foetal samples were collected by using chorionic villus sampling (CVS), amniocentesis or cordocentesis after a written consent was obtained from couples. The CMA platform used was CytoScan 750 K Array (Affymetrix Inc., Santa Clara, CA). All patients were offered counselling by the maternal-foetal medicine team, including the genetic counsellors. The requests for a termination of pregnancy (TOP) were granted for those with a gestational age of fewer than 28 weeks, as well as those who had severe foetal structural defects.