Yuen Ha Ting

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. There were totally six images of IVS obtained for each fetus: live xPlane image, live 3D image, multiplanar image and rendered image with the four-chamber view as the starting plane, multiplanar image and rendered image with the sagittal view of the fetal thorax as the starting plane. These images were grouped into six groups and randomized within each group for the further analysis. The images were scored and compared according to the image quality, the outline of the fetal IVS and motion artefact. The operator was also asked to judge whether VSD existed or not and the results were compared with the final diagnosis. The sensitivity, specificity, false positive percentage, positive likelihood ratio, false negative percentage and negative likelihood ratio of each group were also calculated. Results: There were 15 cases with VSD and four cases without VSD in CHD fetus and 31 cases of normal fetus enrolled in this study. A total 300 images of the lateral view of fetal IVS were obtained and grouped into six groups. The image quality in the group of STIC with the four-chamber view as the starting plane is much worse than the group of STIC with the sagittal view as the starting plane and real-time three-dimensional echocardiography (P < 0.05). There were no significant differences in image quality between the group of STIC with the sagittal view as the starting plane and real-time three-dimensional echocardiography (P > 0.05). Conclusion: The image quality of real-time 3DE is similar to the images acquired by STIC from the sagittal view and superior to that obtained by STIC from the four-chamber view. However, real-time 3DE has no motion artefact, which has the potentials to improve the detection rate of fetal VSD.

Radiofrequency Ablation for Selective Reduction in Complicated Monochorionic Multiple Pregnancies

Objective: To evaluate the perinatal outcome of monochorionic (MC) multiple pregnancies after selective reduction by radiofrequency ablation (RFA). Methods: A case series of all MC multiple pregnancies with selective reduction by RFA in one single institution was reviewed. Results: Ten consecutive patients with an MC pregnancy (9 pairs of twins and 1 set of triplets) underwent RFA. The median gestational age at the time of the procedure was 15.6 weeks (range, 12.3-19.6). The indications for selective reduction included discordance for fetal anomalies (4 cases), twin reversed arterial perfusion sequence (3 cases), selective intrauterine growth restriction (2 cases) and severe twin-twin transfusion syndrome (1 case). All procedures were technically successful in achieving selective reduction. The overall survival rate of the co-twin was 81.8% (9/11), and the median gestational age at delivery was 35.9 weeks (range, 32.4-38.6). There was one preterm delivery before 34 weeks of gestation (11.1%). Preterm premature rupture of the membranes occurred in 2 patients (20%); however, this was not observed within 4 weeks postoperatively, nor did they deliver before 32 weeks. Conclusions: RFA is a promising technique for selective reduction in complicated MC multiple pregnancies with a high survival rate and low complication rate.

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. Results: At presentation, mean cervical length was 1.17 cm (range 0–2.33 cm), mean gestation at pessary insertion and delivery was 20.6 (12.9–26.1) weeks and 32.1 (14.7–40.1) weeks, respectively, and mean prolongation of pregnancy was 11.5 (0.5–25.2) weeks. Overall, 5 (25%) had fetal loss between 14.7–23.1 weeks, while 3 (15%) and 12 (60%) delivered before and after 34 weeks gestation, respectively with no perinatal mortality. Compared with women with cervical length <1.5 cm, all those with cervical length ≥1.5 cm had pregnancy prolonged for ≥49 days (100 vs. 54% p = 0.032) and 86% delivered beyond 34 weeks (86 vs. 46% p = 0.085). Conclusions: Arabin cerclage pessary appears to be optimal for treating women at high risk of cervical insufficiency with a cervical length of 1.5–2.5 cm, while it is an acceptable option for high risk women with cervical length <1.5 cm.

Environmental factors in the first trimester and risk of oral-facial clefts in the offspring.

The averaged incidences of nonsyndromal/isolated cleft lip (CL), cleft palate (CP), and cleft lip with cleft palate (CLCP) by each month-of-conception, and managed in our hospital in from 2002 to 2009 were correlated with the reported levels of sunshine, ultraviolet radiation, and ambient nitrogen oxides (nitrogen oxide, nitrogen monoxide, and nitrogen dioxide), sulfur dioxide, and ozone, at the month of, and then at 4 and 8 weeks after, conception. There were 25, 12, and 22 cases each of CL, CP, and CLCP, respectively, totaling 59 cases (1.21 of 1000 births). On regression analysis, sunshine correlated inversely with the isolated CL at (P = .009) 4 weeks (P = .005) and 8 weeks (P = .008) postconception, and with CP (P = .009) and CLCP (P < .001) at 8 weeks postconception, while NOx correlated inversely with CL (P = .018) and NO with CLCP (P = .031), at 8 weeks postconception. Our results suggested that the interaction between sunshine and nitrogen oxides with other factors results in the reported seasonal variation in the incidence of isolated oral-facial clefts.

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. We used two methods to image the fetal heart with live xPlane imaging: one uses the four-chamber view as the starting plane and the other uses the longitudinal view of fetal upper thorax as the starting plane. Results. When using the four-chamber view as the starting plane, the visualization rate of LVOT, RVOT, and 3VT was 94.1% (48/51), 100% (51/51), and 98.0% (50/51), respectively. When using the longitudinal view as the starting plane, the visualization rate of four-chamber view, LVOT, RVOT, and 3VT was 100% (51/51), 100% (51/51), 41.2% (21/51), and 100% (51/51), respectively. Conclusions. Live xPlane imaging can be used to visualize the screening views of the fetal heart, and potentially may be a useful tool for the assessment and diagnosis of fetal congenital heart diseases.

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. The presence and details of birth defects, the dosage of CMZ, and the period of exposure during pregnancy were examined in these 29 pregnancies. All cases of CMZ embryopathy in the English literature were reviewed in the same way. RESULTS Of the 27 babies (93.1%) with known outcome, 3 had aplasia cutis and 1 had an omphalocele in addition, and 1 affected baby had a sibling with aplasia cutis and patent vitellointestinal duct. The incidence of CMZ embryopathy in our study group is 11.1%. Amongst the 21 cases of CMZ embryopathy in the literature, 85% were exposed to a CMZ dosage of ≥20 mg/day, and the minimum duration of exposure being 7 weeks from last menstrual period. The most common abnormality is ectodermal anomaly (62%), followed by oro-nasal anomaly (48%), facial dysmorphism (38%), gastrointestinal anomaly (33%) and abdominal wall defect (19%). There was no relationship between the type of abnormality and the dosage or duration of exposure to CMZ. CONCLUSIONS The incidence of CMZ embryopathy in our study group is 11.1%. Critical factors for its development are exposure to a CMZ dosage of ≥20 mg/day before 7 weeks of gestation. Genetic susceptibility may also play a role.

A novel way of visualizing the ductal and aortic arches by real-time three-dimensional ultrasound with live xPlane imaging

To describe a novel method of visualizing the ductal and aortic arches by real‐time three‐dimensional echocardiography with live xPlane imaging.

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 log10 equivalent (log10 NTMoM). Central tendency and measurement were assessed by checking whether the median of the NTMoM distribution and SD of the log10 NTMoM distributions were, respectively, within 5% or 10% of the expected median of 1 and SD of 0.1. Assessment was performed using both the Center specific and Fetal Medicine Foundation (FMF) reference NT for Crown rump length (CRL). Results. The median NT MoM was 0.95 MoM using the FMF reference and 1.01 MoM when assessed using our center specific reference median. The difference between the center and FMF derived NT MoMs was statistically significantly (p < 0.0001). NTMoM medians increased over time at a rate of 0.0099 MoM per year while log10 NT MoM measurement dispersement was similar to the 0.1 value expected and decreased by 0.0048 per year. Conclusion. Centers should routinely monitor the quality of NT measurements used to estimate Down syndrome screening risk and should provide individualized feedback to sonographers of their measures of central tendency and dispersion to ensure consistent and improved performance. NT reference medians adopted from other populations should be assessed and validated against a centers own measurement distribution.

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. In our centre, the incidence of PABS was found to be 2%. There were 25 cases of PABS reported previously, of which 12 cases with clinical details were reviewed together with our 3 cases. The fetal limbs were involved in all 15 cases, leading to constriction or amputation. The umbilical cord was involved in 2 cases, resulting in fetal death in one and pregnancy termination in the other. Antenatal detection of PABS is rare (27%; 4/15) as this requires a high index of suspicion. Serial postoperative targeted ultrasound surveillance of the fetal limbs and umbilical cord is necessary, particularly when features of septostomy or chorioamniotic membrane separation are found. Colour Doppler examination for the perfusion of the affected limb should be performed when PABS is detected. Fetoscopic release of amniotic band could salvage the fetal limb from amputation when impaired blood flow is detected.

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 (1.21/1000 births), including 25 CL, 12 CP and 22 CLP cases. The peak incidence was in February (1.96/1000 births) and the lowest in September (0.67/1000 births). There was significant inverse correlation with the months from winter (December) to autumn (November) for all categories except for CP. When analysed by seasons, significant inverse correlation from winter to autumn was observed for all categories, and significant differences in incidence was demonstrated for CL+/-CP and CL. Conclusions: The seasonality in the incidence of oral-facial clefts found in this study suggested that environmental factors are probably involved, which would have accounted for the reported seasonal variations and geographical and racial differences in the incidence in the literature.