Isolated Upward Rotation of the Fetal Cerebellar Vermis (Blake's Pouch Cyst) Is a Normal Variant: An Analysis of 111 Cases.

Introduction: The objective of the study was to provide more detailed data about fetal isolated upward rotation of the cerebellar vermis rotation (Blake's pouch cyst) in particular regarding pregnancy outcome.

Methods: This is a retrospective study of all cases of fetal isolated upward rotation of the cerebellar vermis (URCV) diagnosed in 3 referral centers in Italy from January 2009 to November 2019. Whenever possible, prenatal magnetic resonance imaging (MRI) was performed and a fetal karyotype was obtained.

Risk of Fetal Loss in Pregnancies Undergoing Midtrimester Amniocentesis after Inconclusive Chorionic Villus Sampling.

Objective: To estimate the procedure-related risk of miscarriage in pregnancies undergoing amniocentesis (AC) following inconclusive results for a chorionic villus sampling (CVS).

Methods: This was a multicentric retrospective cohort study of patients in which both CVS at 11-13 weeks' gestation and AC at 16-22 weeks were performed between January 1st, 2008, and July 31st, 2017. The primary outcome measure was pregnancy loss prior to 24 weeks gestation; the secondary one was intrauterine demise after 24 weeks.

Interpreting mosaicism in chorionic villi: results of a monocentric series of 1001 mosaics in chorionic villi with follow-up amniocentesis.

Objectives: Chromosomal mosaicism in chorionic villi (CV) is detected in ~1-2% of cases. When a mosaic in CV is detected during prenatal diagnosis, a confirmatory karyotype should be performed on amniocytes to discriminate between a mosaic confined to the placenta [confined placental mosaicism (CPM)] and one generalized to the fetus [true fetal mosaicism (TFM)]. We determined the likelihood that any mosaic abnormalities identified through CV samples are confirmed in the fetus.

The type of feto-placental aneuploidy detected by cfDNA testing may influence the choice of confirmatory diagnostic procedure.

Objectives: Cell-free DNA (cfDNA) screening can provide false positive/negative results because the fetal fraction originates primarily from trophoblast. Consequently, invasive diagnostic testing is recommended to confirm a high-risk result. Currently, there is debate about the most appropriate invasive method.

Attitudes of women of advanced maternal age undergoing invasive prenatal diagnosis and the impact of genetic counselling.

Despite the increasing availability and effectiveness of non-invasive screening for foetal aneuploidies, most women of advanced maternal age (AMA) still opt for invasive tests. A retrospective cross-sectional survey was performed on women of AMA undergoing prenatal invasive procedures, in order to explore their motivations and the outcome of preliminary genetic counselling according to the approach (individual or group) adopted. Of 687 eligible women, 221 (32.

Prenatal phenotype of Williams-Beuren syndrome and of the reciprocal duplication syndrome.

Copy losses/gains of the Williams-Beuren syndrome (WBS) region cause neurodevelopmental disorders with variable expressivity. The WBS prenatal diagnosis cannot be easily performed by ultrasound because only few phenotypic features can be assessed. Three WBS and the first reciprocal duplication prenatal cases are described with a review of the literature.

Prenatal diagnosis versus first-trimester screening of trisomy 21 among pregnant women aged 35 or more.

Objective: To compare the policy of prenatal diagnosis versus first trimester screening of trisomy 21 among pregnant women of advanced age.

Methods: A retrospective study was conducted on patients aged ≥35 divided in two groups: patients who requested first trimester combined test and only in case of screen-positive result underwent invasive testing (group A); patients undergoing chorionic villous sampling or amniocentesis as first investigation (group B). The following outcome variables were compared: antenatal detection of trisomy 21, occurrence of trisomy 21 at birth, miscarriage rate, hospitals' costs.

Cytogenetic follow-up of chromosomal mosaicism detected in first-trimester prenatal diagnosis.

Objective: To contribute to the risk assessment of true fetal mosaicism after detection of a mosaic chromosomal anomaly in chorionic villus samples (CVS) in order to enable more effective counseling and pregnancy management.

Methods: We retrospectively reviewed 7112 consecutive CVS analyzed on both direct preparations and cultured cells. In 135 out of the 177 cases of mosaicism, we performed cytogenetic follow-up and determined the frequency of confined placental mosaicism (CPM) and true fetal mosaicism according to type and distribution of the cytogenetic abnormality.

Structural chromosomal abnormalities detected during CVS analysis and their role in the prenatal ascertainment of cryptic subtelomeric rearrangements.

Mosaic structural chromosomal abnormalities observed along the trophoblast-mesenchyme-fetal axis, although rare, pose a difficult problem for their prognostic interpretation in prenatal diagnosis. Additional issues are raised by the presence of mosaic imbalances of the same chromosome showing different sizes in the different tissues, that is, deletions and duplications in the cytotrophoblast and mesenchyme of chorionic villi (CV). Some of these cytogenetic rearrangements originate from the post-zygotic breakage of a dicentric chromosome or of the product of its first anaphasic breakage.

Complex rearrangement of the exon 6 genomic region among Opitz G/BBB Syndrome MID1 alterations.

Opitz G/BBB Syndrome (OS) is a multiple congenital anomaly disorder characterized by developmental defects of midline structures. The most relevant clinical signs are ocular hypertelorism, hypospadias, cleft lip and palate, laryngo-tracheo-esophageal abnormalities, imperforate anus, and cardiac defects. Developmental delay, intellectual disability and brain abnormalities are also present.

Persistence of a monosomic cell line in a fetus with mosaic trisomy 8.

We report on a fetus presenting with an increased nuchal translucency, in which chorionic villus sampling led to the diagnosis of mosaic trisomy 8. Ultrasound scan performed at 15(+6) weeks revealed bilateral cleft lip and palate, flat facial profile, and arrhinia. Pregnancy was terminated at 16(+6); postmortem examination showed additional findings including hypospadias, bilateral renal dysplasia, and focal portal fibrosis of the liver.