Renal and extra-renal phenotypes in a fetus with a de novo pathogenic variant in the HNF1B gene.

We report a fetus with prenatal ultrasound at 21 gestational weeks showing left cystic renal dysplasia with subcapsular cysts and echogenic parenchyma, right echogenic kidney with absent corticomedullary differentiation, and left congenital diaphragmatic hernia (CDH) with bowel herniation, with intestinal atresia (IA) found on postmortem examination. Whole genome sequencing of fetal blood DNA revealed a heterozygous pathogenic variant c.344 + 2 T>G in the HNF1B gene (NM_000458).

Diagnostic Yield of Exome Sequencing in Fetuses with Sonographic Features of Skeletal Dysplasias but Normal Karyotype or Chromosomal Microarray Analysis: A Systematic Review.

Skeletal dysplasias are a group of diseases characterized by bone and joint abnormalities, which can be detected during prenatal ultrasound. Next-generation sequencing has rapidly revolutionized molecular diagnostic approaches in fetuses with structural anomalies. This review studies the additional diagnostic yield of prenatal exome sequencing in fetuses with prenatal sonographic features of skeletal dysplasias.

Determining chorionicity and amnionicity in twin pregnancies: Pitfalls.

Although the accuracy of chorioamnionicity determination in multiple pregnancy is nearly 100%, some pitfalls do exist. These pitfalls may arise from some confusing sonographic appearance or because of certain rare variations of twinning going against the general principles. Pitfalls in chorionicity determination include (1) the disappearance of the twin peak sign with the regression of chorion frondosum and thinning of the intertwin membrane with advancing gestation; (2) fake twin peak sign because of other structures creeping into the intertwin membrane-placental junction; (3) intrauterine septum or synechia being mistaken as a thick intertwin membrane; (4) bipartite placenta in monochorionic twin being misinterpreted as two separate placentas of dichorionic twin; (5) erroneous fetal sex determination in sex chromosome mosaicism, monogenic disorders, and malformed genitalia in one fetus; and (6) rare twinning types such as dizygotic monochorionic twin and sesquizygotic twin.

Impact of replacing or adding placental growth factor on Down syndrome screening: A prospective cohort study.

Objectives: To assess whether adding placental growth factor (PlGF) or replacing pregnancy-associated plasma protein-A (PAPP-A) improves the first trimester combined test performance for trisomy 21.

Methods: A total of 11,518 women with a singleton pregnancy who underwent the first trimester combined test between December 2016 and December 2019 were included. PlGF was measured and estimated term risk for trisomy 21 was calculated by (1) adding PlGF to the combined test and (2) replacing PAPP-A with PlGF.

The Use of Somatex Shunt for Fetal Pleural Effusion: A Cohort of 8 Procedures.

Introduction: Fetal pleural effusion may require in utero shunting which is associated with procedure-related complications.

Objective: To evaluate the efficacy and complications of the newly designed Somatex shunt in treating fetal pleural effusion.

Methods: Consecutive cases with primary fetal pleural effusion who were treated with the Somatex shunt between 2018 and 2019 were evaluated.

The utility of genome-wide cell-free DNA screening in the prenatal diagnosis of Pallister-Killian syndrome.

Objective: To report genome-wide cell-free DNA (cfDNA) screening facilitating the diagnosis of Pallister-Killian syndrome (PKS).

Methods: This is a retrospective cohort analysis of positive genome-wide cfDNA screening results showing increased signal from chromosome 12 and the detection of PKS. The genome-wide cfDNA screening results and the subsequent investigations were reviewed.

Objective assessment of the fetal facial profile at second and third trimester of pregnancy.

Objective: To investigate the intraobserver and interobserver reproducibility of a novel sonographic parameter named facial maxillary angle (FMA) and to establish nomograms of FMA, inferior facial angle (IFA), frontal nasal-mental angle (FNMA), maxilla-nasion-mandible angle (MNMA), and fetal profile line (FPL) in Chinese fetuses.

Methods: In this prospective cross-sectional study, FMA, IFA, FNMA, MNMA, and FPL were measured in 592 normal fetuses between 16 and 36 gestational weeks. FMA was measured twice by the same and another operator with a blinded method on the first 50 cases.

Hypoechoic liver in fetuses with trisomy 21.

The association between hypoechoic hepatomegaly in the third trimester and transient abnormal myelopoiesis (TAM) was reported previously in six fetuses with trisomy 21 (T21). We report a series of three cases of T21 in which hypoechoic liver (HL) was found in the second trimester but without evidence of TAM on both hematological and histological examination. We postulate that the hypo-echogenicity may be due to liver congestion secondary to hemodynamic disturbances seen in T21 fetuses.

Pitfalls in assessing chorioamnionicity: novel observations and literature review.

Accurate diagnosis of chorioamnionicity in multiple pregnancies is the key to appropriate clinical management of multiple gestation. Although prenatal ultrasound assessment of chorioamnionicity is well established and highly accurate if performed in early pregnancy, exceptions and artifacts arise from anatomic variations in multiple pregnancies and unusual sonographic features do exist. We have summarized our own experiences and reports from the literature on these pitfalls as follows: (1) discordant fetal sex in monochorionic pregnancies due to sex chromosome abnormalities, genital malformation in 1 fetus, or dizygotic twins forming a monochorionic placenta; (2) separate placental masses in monochorionic pregnancies due to bipartite placenta; (3) false-negative and false-positive λ sign can arise for various reasons, and in partial monochorionic/dichorionic placentas both T and λ sign may co-exist; (4) intrauterine synechia appearing as a thick and echogenic intrauterine septum may lead to erroneous diagnosis of dichorionic twins; and (5) errors in ascertaining amnionicity by the visualization of thin intertwin amniotic membranes and the number of yolk sacs.

Uterine artery pulsatility index in the first trimester: assessment of intersonographer and intersampling site measurement differences.

Objective: To determine intersonographer, intersampling site pulsatility index differences in the ascending branch of the uterine artery (UtA-PI) and their effect on detection rates (DR) for early onset preeclampsia (PE).

Methods: A prospective observational study was conducted including 52 women with singleton viable pregnancy at 11-13 weeks' gestation. Consecutive bilateral UtA-PI measurements were performed by two sonographers.

Pseudoamniotic Band Syndrome after In Utero Intervention for Twin-to-Twin Transfusion Syndrome: Case Reports and Literature Review.

Pseudoamniotic band syndrome (PABS) is a rare iatrogenic complication that arises after invasive procedures in monochorionic twins. We report 3 cases of PABS, 2 after fetoscopic laser photocoagulation and 1 after bipolar cord coagulation. Two cases were detected antenatally by ultrasound; out of the two, one underwent successful fetoscopic release of amniotic band, which is the first report in twin pregnancy to our knowledge.

The influence of image setting on intracranial translucency measurement by manual and semi-automated system.

Objective: To investigate the agreement between manual and semi-automated system and the effect of different image settings on intracranial translucency (IT) measurement.

Methods: A prospective study was conducted on 55 women carrying singleton pregnancy who attended first trimester Down syndrome screening. IT was measured both manually and by semi-automated system at the same default image setting.

Detection of the fetal conotruncal anomalies using real-time three-dimensional echocardiography with live xPlane imaging of the fetal ductal arch view.

Objective: To evaluate the role of live xPlane imaging of ductal arch view in detection of fetal conotruncal anomalies.

Methods: Two hundred selected singleton pregnancies, including 152 normal cases, 27 conotruncal anomalies and 21 other types of fetal heart abnormalities were enrolled in this observational study. All the cases were scanned to visualize the ductal arch view with live xPlane imaging by a single observer.

Carbimazole embryopathy in a Chinese population: case series and literature review.

Background: The data in the literature suggests that Methimazole (MMI)/Carbimazole (CMZ) embryopathy is rare. This study examined the incidence of CMZ embryopathy in the Hong Kong Chinese population and the factors associated with its development.

Methods: Of the 145 pregnant women with hyperthyroidism managed from 2008 to 2010, 29 (20%) had taken CMZ during pregnancy.

Can live xPlane imaging of the in-plane view of interventricular septum be used to detect fetal conotruncal anomalies?

Objective: To evaluate the feasibility of live xPlane imaging visualizing the in-plane view of IVS in the screening of the fetal conotruncal anomalies.

Method: One hundred and fifty-two consecutive normal singleton fetuses and forty-eight fetal cardiac defects (27 conotruncal and 21 non-conotruncal cases), were enrolled in this study. The in-plane view of IVS was firstly acquired with live xPlane imaging and then judged whether it is normal or not by one operator.

Arabin cerclage pessary in the management of cervical insufficiency.

Objective: To evaluate the use of Arabin cerclage pessary in the management of cervical insufficiency.

Methods: The pregnancy outcome of 20 women carrying singleton pregnancy referred for suspected cervical insufficiency and chose Arabin cerclage pessary for treatment from 2009-2011 were reviewed. Pregnancy outcome were analysed according to presence of risk factors, amniotic fluid sludge, cervical length and gestation at pessary insertion.

Comparison of real-time three-dimensional echocardiography and spatiotemporal image correlation in assessment of fetal interventricular septum.

Objective: To compare the role of real-time 3DE and STIC technology in assessment of the fetal IVS.

Methods: Fifty pregnant women with singleton pregnancies were invited to attend this study. All the fetuses were examined by both spatiotemporal image correlation and real-time three-dimensional echocardiography.

Systematic identification of spontaneous preterm birth-associated RNA transcripts in maternal plasma.

Background: Spontaneous preterm birth (SPB, before 37 gestational weeks) is a major cause of perinatal mortality and morbidity, but its pathogenesis remains unclear. Studies on SPB have been hampered by the limited availability of markers for SPB in predelivery clinical samples that can be easily compared with gestational age-matched normal controls. We hypothesize that SPB involves aberrant placental RNA expression, and that such RNA transcripts can be detected in predelivery maternal plasma samples, which can be compared with gestational age-matched controls.

Is there Seasonality in the Incidence of Oral-Facial Clefts?

Abstract Objective: To determine if seasonal variation in the incidence of oral-facial clefts exists in the Hong Kong Chinese population. Methods: Cases of non-syndromal oral-facial clefts identified from the Prenatal Diagnostic Clinic database from 2002-2009, and total births from our departmental statistics during this period, were used to calculate the averaged month-of-conception incidence for overall cases and individual categories of clefts, including cleft lip (CL), cleft palate (CP), cleft lip with/without cleft palate (CL+/-CP), and cleft lip with cleft palate (CLP). Results: There were 59 eligible cases (1.

Scan the fetal heart by real-time three-dimensional echocardiography with live xPlane imaging.

Objective: To describe the methodology of live xPlane imaging in the visualization of the fetal heart in detail.

Methods: Fifty-one consecutive pregnant women with singleton pregnancies were imaged to display four screening sections of the fetal heart, the four-chamber view, the left outflow tract view (LVOT), the right outflow tract view (RVOT), and the three-vessel and trachea view (3VT), using live xPlane imaging. The methodology of how to visualize the screening planes was described in detail.

Outcome of monochorionic twin pregnancies with abnormal umbilical artery Doppler between 16 and 20 weeks of gestation.

Objectives: To study the perinatal outcome among monochorionic diamniotic (MCDA) twin pregnancies with absent or reversed end-diastolic flow of the umbilical artery (UA-AREDF) at 16-20 weeks of gestation.

Methods: This was a retrospective study of 84 MCDA twin pregnancies, which were followed up since first trimester in a single obstetric unit. Pregnancies with fetal structural anomalies or genetic syndromes, and those with single intrauterine death before 16 weeks were excluded.

Isolated absent or hypoplastic nasal bone in the second trimester fetus: is amniocentesis necessary?

Objective: To elucidate the significance of isolated absent or hypoplastic nasal bone in the second trimester ultrasound scan.

Methods: All cases of absent or hypoplastic nasal bone (length < 5th percentile) encountered during 2007-2009 were retrieved from database and all the ultrasound findings including structural abnormalities and soft markers for Down syndrome and fetal karyotype were reviewed. The cases were categorized into a study group with isolated absent or hypoplastic nasal bone and a comparison group with additional ultrasound findings.

Assessment of sonographer nuchal translucency measurement performance--central tendency and dispersion.

Objective: To assess center and sonographer nuchal translucency (NT) measurements that were performed as part of routine prenatal screening for Down syndrome.

Methods: Sonographers were assessed for measures of central tendency and dispersion by comparing them with expected population median and dispersion parameters. NT measurements were converted to multiples of the expected NT values according to CRL (NTMoM) and transformed to their log(10) equivalent (log(10) NTMoM).