Search PubMed⌕ Search

Biomedical subjects

W C Leung

Publications and source records attributed to W C Leung.

At least 19 recordsLinked to original sources
PubMed2007

Reversed diastolic flow in the uterine artery - a new Doppler finding related to placental insufficiency?

Increased uterine artery pulsatility and resistance indices with or without notching of the waveform have been associated with an increased risk of pre-eclampsia and fetal growth restriction. However, reversed diastolic flow in the uterine artery has not previously been reported. We present two high-risk obstetric cases complicated by severe placental insufficiency: pre-eclampsia followed by eclampsia in one case and intrauterine growth restriction with abnormal cardiotocography in the other. Doppler studies of the uterine arteries revealed reversed diastolic flow in both cases. The pathophysiology and potential implications are discussed.

Adult↗
PubMed2006

Continued reduction in the incidence of birth trauma and birth asphyxia related to instrumental deliveries after the study period: was this the Hawthorne effect?

BACKGROUND: The incidence of birth trauma and birth asphyxia related to instrumental deliveries in our obstetric unit was high (2.8%) in 1998-1999. A study was performed in 2000 to identify the risk factors. Unexpectedly, the incidence (0.6%) was reduced significantly during the study period. We attributed this phenomenon to the famous Hawthorne effect (tendency to improve performance because of awareness of being studied). OBJECTIVES: The objectives were to study whether there is a continued reduction in the incidence of birth trauma and birth asphyxia related to instrumental deliveries in the post-study period (2001-2003) and to investigate the presence of underlying confounding factors apart from the Hawthorne effect. METHOD: To compare the hospital obstetric statistics among the pre-study period (1998-1999), the study period (2000) and the post-study period (2001-2003), in particular the incidence of birth trauma and birth asphyxia related to instrumental deliveries, the instrumental delivery rate, the overall Caesarean section rate, the Caesarean section rate for no progress of labour, the incidence of failed instrumental delivery, the incidence of attempted instrumental delivery in the operating theatre, and incidence of direct second-stage Caesarean sections. RESULTS: The incidence of birth trauma and birth asphyxia related to instrumental deliveries (0.6%) during the study period (2000) was significantly lower than that (2.8%) during the pre-study period (1998-1999; RR 0.27, 95% CI 0.11-0.70). This phenomenon continued into the post-study period (2001-2003) when the incidence of 1.0% was similarly lower than that in the pre-study period (RR 0.35, 95% CI 0.20-0.64). The instrumental delivery rate decreased further in the post-study period (13.5%) compared with those in the study (16.6%) and pre-study (19.5%) periods (RR 0.81, 95% CI 0.75-0.89 and RR 0.69, 95% CI 0.65-0.74, respectively). There was a marked increase in the direct second-stage Caesarean section rate in the post-study period (7.1%) compared to those in the study (0.4%) and pre-study (0.7%) periods (RR 15.9, 95% CI 5.05-49.73 and RR 9.77, 95% CI 5.28-18.08, respectively). CONCLUSION: A change in obstetric practice was identified that may explain the continued reduction in the incidence of birth trauma and birth asphyxia related to instrumental deliveries in the post-study period.

Asphyxia Neonatorum↗
PubMed2006

Full karyotyping, rapid aneuploidy diagnosis or both when invasive prenatal testing is performed for diagnosis of thalassaemia?

A retrospective study was performed to compare the detection rate of chromosomal abnormalities by different approaches of full karyotyping, rapid aneuploidy diagnosis (RAD) or both when invasive prenatal testing is performed for diagnosis of thalassaemia. The karyotype results of 1120 prenatal samples obtained from thalassaemia couples from January 1985 to December 2002 in a referral centre for prenatal diagnosis were studied. The detection rate of chromosomal abnormalities by four different approaches were compared: (i) karyotyping for all samples; (ii) RAD (21,18,13,X,Y) for all samples; (iii) RAD for all samples + karyotyping for cases with ultrasound abnormalities; and (iv) RAD (21,18,13) for all + RAD (X,Y) for cases with ultrasound abnormalities consistent with Turner syndrome + karyotyping for cases with ultrasound abnormalities. Normal karyotypes were found in 1103 samples (98.5%). There were 17 cases (1.5%) of chromosomal abnormalities: four cases (0.36%) were clinically significant, eight cases (0.7%) were of borderline clinical significance and five cases (0.44%) were not confirmed by subsequent prenatal or postnatal tests. The incidences of autosomal (7/1120 = 0.63%) and sex chromosomal (5/1120 = 0.45%) abnormalities were not higher than those (0.41 and 0.22%, respectively) from newborn surveys (Hook and Hamerton, 1977) (P = 0.398 and 0.216, respectively). Approach 1 would detect all 17 chromosomal abnormalities. Approach 2 would detect three of four clinically significant chromosomal abnormalities but not detect six of eight chromosomal abnormalities of borderline clinical significance and three of five chromosomal abnormalities not confirmed by subsequent prenatal or postnatal tests. Approach 3, in addition, would be able to detect all four clinically significant chromosomal abnormalities. Approach 4 would detect all four clinically significant chromosomal abnormalities but would not detect seven of eight chromosomal abnormalities of borderline clinical significance and four of five chromosomal abnormalities not confirmed by subsequent prenatal or postnatal tests. RAD (21,18,13) for all + RAD (X,Y) for cases with ultrasound abnormalities consistent with Turner syndrome + karyotyping for cases with ultrasound abnormalities seemed to be the best approach for the detection of chromosomal abnormalities when invasive prenatal testing is performed for diagnosis of thalassaemia.

Adolescent↗
PubMed2006

The effects on maternal anxiety of two-dimensional versus two- plus three-/four-dimensional ultrasound in pregnancies at risk of fetal abnormalities: A randomized study.

OBJECTIVE: To test the hypothesis that the use of two-dimensional (2D) ultrasonography with three-dimensional/four-dimensional (3D/4D) ultrasonography can reduce anxiety to a greater extent in women at risk of having a fetus with congenital abnormalities than the use of 2D ultrasonography alone. METHODS: A total of 124 women attending the prenatal diagnostic clinic of a teaching hospital were randomized into the intervention group (2D ultrasonography followed by 3D/4D ultrasonography) or control group (2D ultrasonography alone). The primary outcome was maternal anxiety levels, which were assessed by the Spielberger state-trait anxiety inventory. We measured the anxiety levels in all women at the first visit, at around 18 weeks' gestation (immediately after ultrasound examinations) and at 28 weeks' gestation. RESULTS: A short-term reduction of the state-anxiety score (by around 2 points) from the first visit to after ultrasound examinations was observed in both the intervention group and the control group. Unexpectedly, a small increase in the state-anxiety score from the first visit to 28 weeks' gestation was observed in the intervention group but not in the control group, though there was no significant difference in the changes between the two groups. Repeated measures ANOVA (analysis of variance) also showed that there was no significant interaction effect between groups and time of assessment on the state-anxiety scores (F = 1.072 and P = 0.344). About 80% of women reported a better understanding that their baby was normal after viewing 3D rather than 2D images. CONCLUSION: This randomized study indicates that the addition of 3D/4D ultrasound does not cause a significant reduction in maternal anxiety in pregnancies at risk of fetal abnormalities compared with conventional 2D ultrasound alone.

Adult↗
PubMed2006

Prevalence of workplace violence against nurses in Hong Kong.

OBJECTIVES: To determine the prevalence and nature of workplace violence against nurses, and how nurses deal with such aggression; and to identify the risk factors related to violence in the hospital environment. DESIGN: Cross-sectional questionnaire study. SETTING: University teaching hospital, Hong Kong. PARTICIPANTS: All nursing staff in the hospital, except nurses who were unable to read Chinese or who did not have patient contact (eg those worked in administrative positions), were invited to complete a questionnaire. MAIN OUTCOME MEASURES: Demographic data of the respondents, incidence of and risk factors contributing to workplace violence. RESULTS: A total of 420 nurses returned the completed questionnaire (response rate, 25%). Three hundred and twenty (76%; 95% confidence interval, 72-80%) nurses reported abuse of any kind--verbal abuse, 73%; bullying, 45%; physical abuse, 18%; and sexual harassment, 12%. Most (82%) nurses who experienced verbal abuse tended to confide in friends, family members, or colleagues. Some (42%) ignored the incident. Risk factors for workplace violence included: working in male wards and in certain specialties such as the Accident and Emergency Department, Community Nursing Service, and the Orthopaedics and Traumatology Department. CONCLUSION: Workplace violence against nurses is a significant problem in Hong Kong. Further large-scale studies should be conducted to more closely examine the problem.

Adaptation, Psychological↗
PubMed2006

Splenic rupture in a premature neonate.

Splenic injuries are very rare in neonates. We report a case of splenic injury in a premature neonate, highlighting the importance of a high-index suspicion in early recognition of this rare but potentially fatal intra-abdominal injury. We also review the literature on possible aetiologies and mechanism of splenic injury, as well as its management. This is the first reported case of a very low-birth-weight neonate with splenic rupture who survived with intact neurology.

Cesarean Section↗
PubMed2006

Recurrent pneumothorax in pregnancy: what should we do after placing an intercostal drain.

Recurrent pneumothorax is rare during pregnancy. We describe a Chinese woman, with a history of spontaneous pneumothorax managed with an intercostal drain, who developed a recurrent pneumothorax during her 32nd week of pregnancy. There is no consensus on management in this situation. We review the literature and discuss different management approaches. Thirty-six cases of antepartum pneumothorax have been reported in 31 case reports. An intercostal drain only (n=11) or surgeries (thoracotomy, n=9; or video-assisted thoracoscopy, n=2) were common treatment options with no surgical complications reported. Twenty-two (61%) patients progressed to a normal vaginal delivery, while the rest required forceps delivery (22%) or Caesarean section (14%). No single treatment option outweighed the others. There were no maternal or foetal complications reported in those who underwent antepartum surgical intervention. Surgical management of recurrent pneumothorax during pregnancy is well tolerated.

Adult↗
PubMed2005

Relationship between cerebroplacental Doppler ratio and birth weight in postdates pregnancies.

OBJECTIVES: To explore the relationship between cerebroplacental Doppler impedance index and birth weight in postdates pregnancies, and to evaluate the use of a combination of Doppler parameters and ultrasound biometry in the prediction of large-for-gestational age (LGA) fetuses at 41 weeks of gestation. METHODS: The pulsatility indices of the umbilical (UA-PI) and middle cerebral (MCA-PI) arteries, the cerebroplacental pulsatility index ratio (CPR) and the estimated fetal weight (EFW) were obtained in a cohort of 181 ultrasound-dated pregnancies at 41 weeks' gestation, 2 days before induction of delivery. A regression equation was established and the correlation between umbilical artery impedance and different birth-weight centile groups was determined. A receiver-operating characteristics (ROC) curve was used to compare prediction of LGA fetuses using biometry alone with that using biometry and UA-PI. RESULTS: UA-PI was inversely related to EFW (Spearson's correlation coefficient rho = -0.28, P < 0.001). Logistic regression showed an independent contribution of UA-PI to the birth-weight estimation (birth weight = 1356.8 - 232.0 x UA-PI + 0.65 x EFW). On ROC curve analysis, the prediction of LGA with the regression equation was comparable to that using ultrasound biometry alone. CONCLUSION: UA-PI was inversely correlated to EFW, but the combination of ultrasound biometry and UA-PI compared with biometry alone showed similar prediction of LGA fetuses in postdates pregnancies. Further prospective trials on larger populations or groups with a higher prevalence of LGA fetuses would be needed to validate the use of the new formula.

Adult↗
PubMed2005

Unexpected intrauterine death following resolution of hydrops fetalis after betamethasone treatment in a fetus with a large cystic adenomatoid malformation of the lung.

Without intervention, the development of hydrops fetalis secondary to cystic adenomatoid malformation of the lung (CAML) implies a 100% mortality rate. Conversely, four CAML cases with in-utero resolution of hydrops fetalis after prenatal betamethasone therapy with good clinical outcome have been reported in the literature. The mechanism is speculated to be the effect of corticosteroid in improving lung maturation. Here we present another CAML case with resolution of hydrops fetalis after prenatal betamethasone therapy but which was followed by later intrauterine death. We speculate that the resolution of the CAML lesion itself may be more important in determining the clinical outcome than the resolution of hydrops. The association between prenatal betamethasone therapy and resolution of hydrops may be related to a different mechanism other than improvement of lung maturation.

Adult↗
PubMed2005

Three-dimensional extended imaging: a new display modality for three-dimensional ultrasound examination.

OBJECTIVE: To describe Three-Dimensional eXtended Imaging (3DXI) as a new display modality for three-dimensional (3D) ultrasound examination of the fetus. METHODS: The spine, palate, heart and brain were evaluated using 3D ultrasound examination at a mean gestational age of 22 weeks in 35, 31, 32 and 31 fetuses, respectively. The volume data captured were analyzed using the conventional orthogonal display mode (ODM), as well as the 3DXI, which includes the Multi-Slice View (MSV) mode and the Oblique View (OBV) mode. The MSV mode allows simultaneous display of multiple sequential parallel planes while the OBV mode allows examination of a non-standard straight or curved plane. RESULTS: The MSV mode allowed a simultaneous display of multiple sequential parallel planes of the fetal structures, but we found some uncertainty if an isolated image in one of the multi-slice images represented the exact level of a fetal structure. The MSV mode was advantageous in one of the six cases of facial cleft by allowing the simultaneous display of bilateral clefts that were located in two different axial planes. The multi-slice images were helpful in making the diagnosis in one case of holoprosencephaly. The OBV mode allowed examination of the coronal plane across the curvature of the spine, and the 'in-plane' view of the interventricular septum in a non-gated study. CONCLUSION: The 3DXI can display the volume data in a different manner from that which usually results from the use of more conventional ODM, and provide additional information over conventional two-dimensional sonography.

Cardiovascular Abnormalities↗
PubMed2005

Quality of life of victims of intimate partner violence.

OBJECTIVE: To evaluate the impact of intimate partner violence on the quality of life in Obstetric/Gynecological (OBGYN) patients. METHOD: A total of 1614 OBGYN patients were classified into four groups (Group 1: requesting termination of pregnancy, n=300; Group 2: infertility patients, n=500; Group 3: other general gynecological patients, n=300; Group 4: obstetric patients, n=514) were successfully interviewed in the absence of their male partners, using a structured questionnaire modified from the Abuse Assessment Screen Questionnaire. Those who reported ever having been abused, together with an equal number of non-abused women as controls, were asked to complete the World Health Organization Quality of Life Measure - Abbreviated version (Hong Kong) Questionnaire. RESULTS: The overall lifetime prevalence of intimate partner violence was 7.2%, with the lifetime prevalence being 12.7%, 1.8%, 4.7%, and 10.9% respectively in Groups 1-4. The mean quality of life domain scores among the abused victims were significantly lower in the physical health domain, social relationship domain, environment domain and psychological health domain. CONCLUSION: The baseline quality of life of the victims of intimate partner violence is significantly impaired compared with the non-abused controls.

Abortion, Induced↗
PubMed2005

The use of fetal Doppler cerebroplacental blood flow and amniotic fluid volume measurement in the surveillance of postdated pregnancies.

BACKGROUND: This prospective observational study aims at determining the distribution of fetal cerebro-placental Doppler indices and amniotic fluid volume in a homogenous group of uncomplicated postdated pregnancies at 41 weeks. The correlation with incidence of passage of thick meconium-stained liquor in labor was analyzed to decide which parameter would be useful in the surveillance of postdated pregnancies. METHODS: The amniotic fluid volume, middle cerebral artery pulsatility index, umbilical artery pulsatility index, and cerebroplacental ratio were measured and distribution determined in 118 well-dated singleton pregnancies admitted for routine induction of labor at 41 weeks. The 10th centile and the 90th centile in each Doppler parameter and amniotic fluid volume were chosen to divide each parameter into three centile groups. The prevalence of thick meconium-stained liquor in labor in different Doppler and amniotic fluid volume centile groups was compared using Chi-square test for trend with P < 0.05 taken as statistically significant. RESULTS: The prevalence of thick meconium-stained liquor in labor was significantly inversely correlated with the middle cerebral artery pulsatility index (P = 0.008), with significant difference across different middle cerebral artery pulsatility index centile groups (P = 0.02). There was no significant difference in the prevalence of thick meconium-stained liquor in labor or oligohydramnios across different umbilical artery pulsatility index centile groups. Neither was there significant difference in the prevalence of thick meconium-stained liquor in labor and oligohydramnios across different cerebroplacental ratio and amniotic fluid volume centile groups. Logistic regression using the 10th centile of middle cerebral artery pulsatility index confirmed that it was a significant independent predicting factor for risk of thick meconium-stained liquor in labor with adjusted odds ratio (95th CI) of 6.14 (1.6-24.1). CONCLUSION: Middle cerebral artery pulsatility index is better than amniotic fluid volume or umbilical artery pulsatility index in predicting the risk of thick meconium-stained liquor in labor in uncomplicated postdated pregnancy at 41 weeks.

Adult↗
PubMed2005

A randomised controlled trial of empowerment training for Chinese abused pregnant women in Hong Kong.

OBJECTIVE: To evaluate the effectiveness of an empowerment intervention in reducing intimate partner violence (IPV) and improving health status. DESIGN: Randomised controlled trial. SETTING: Antenatal clinic in a public hospital in Hong Kong. SAMPLE: One hundred and ten Chinese pregnant women with a history of abuse by their intimate partners. METHODS: Women were randomised to the experimental or control group. Experimental group women received empowerment training specially designed for Chinese abused pregnant women while the control group women received standard care for abused women. Data were collected at study entry and six weeks postnatal. MAIN OUTCOMES MEASURES: IPV [on the Conflict Tactics Scale (CTS)], health-related quality of life (SF-36) and postnatal depression [Edinburgh Postnatal Depression Scale (EPDS)]. RESULTS: Following the training, the experimental group had significantly higher physical functioning and had significantly improved role limitation due to physical problems and emotional problems. They also reported less psychological (but not sexual) abuse, minor (but not severe) physical violence and had significantly lower postnatal depression scores. However, they reported more bodily pain. CONCLUSION: An empowerment intervention specially designed for Chinese abused pregnant women was effective in reducing IPV and improving the health status of the women.

Adult↗
PubMed2004

Doppler study of the umbilical and fetal middle cerebral arteries in women with gestational diabetes mellitus.

OBJECTIVE: To investigate the correlation between Doppler parameters in the umbilical and fetal middle cerebral arteries and pregnancy outcome in women with gestational diabetes mellitus (GDM). METHODS: A prospective study was performed on 169 singleton GDM pregnancies in a university teaching hospital from January to December 2002. Umbilical artery (UA) pulsatility index (PI) and middle cerebral artery (MCA) PI and peak systolic velocity (Vmax) were measured every 4 weeks until delivery from the time of diagnosis of GDM. The pregnancy outcome was obtained from the hospital database. Using linear or quadratic regression, lines of best fit were drawn to compare the Doppler measurements between the two groups with normal and abnormal pregnancy outcomes. RESULTS: One hundred and thirty-eight women with known pregnancy outcome completed the study. A total of 305 Doppler examinations were performed with one to four examinations for each woman. Thirty-eight women (27.5%) had one or more abnormal pregnancy outcomes: placental abruption, pre-eclampsia, preterm delivery, small-for-gestational age (SGA) infants, low Apgar scores, neonatal jaundice requiring treatment, sepsis, birth trauma, meconium aspiration syndrome, respiratory and neurological complications. There was extensive overlap of the UA-PI, MCA-PI and MCA-Vmax measurements between the two groups. CONCLUSION: A Doppler study of the UA-PI, MCA-PI and MCA-Vmax was not useful in the prediction of abnormal pregnancy outcome in GDM.

Blood Flow Velocity↗
PubMed2004

Procedure-related complications of rapid amniodrainage in the treatment of polyhydramnios.

OBJECTIVE: To investigate the procedure-related complications of rapid amniodrainage in the treatment of polyhydramnios. METHODS: We followed prospectively all patients with polyhydramnios treated with rapid amniodrainage under continuous ultrasound guidance using a vacuum wound-drainage system from 1995 to 2002 in the fetal medicine unit of a university teaching hospital. We recorded: maternal age, type of pregnancy (singleton/twin), cause of polyhydramnios, gestational age at amniocentesis, volume of amniotic fluid drained, duration of the procedure, other intrauterine procedures in addition to the amniodrainage, and procedure-related complications including placental abruption, premature rupture of membranes (PROM), chorioamnionitis, fetal bradycardia and preterm delivery within 48 h of amniodrainage. RESULTS: Seventy-four consecutive women had 134 rapid amniodrainage procedures during the study period. Four procedures were excluded because the women were already in labor at the time of amniodrainage and they delivered within 48 h of the procedure. The final database therefore consisted of 70 patients with 130 procedures. Sixty-two percent (80/130) of the procedures were performed for the treatment of twin-twin transfusion syndrome (TTTS). There were altogether four procedure-related complications (3.1%; 95% CI, 1.0-8.0%). Three of them occurred in the TTTS group (3/80 procedures, 3.8%; 95% CI, 1.0-11.0%): one case each of placental abruption, PROM and fetal bradycardia. One PROM occurred in the non-TTTS group (1/50 procedures, 2.0%; 95% CI, 0-11.0%). In both cases of PROM the women presented in labor. CONCLUSIONS: Rapid amniodrainage using a vacuum wound-drainage system is safe and efficient to treat severe polyhydramnios, with a 3.1% complication rate.

Amniocentesis↗
PubMed2004

Rapid aneuploidy screening (FISH or QF-PCR): the changing scene in prenatal diagnosis?

The accuracy of new molecular diagnostics, fluoresence in situ hybridization or quantitative fluorescence-PCR (collectively known as rapid aneuploidy screening), in prenatal diagnosis has already been demonstrated in a number of large studies. The challenge now is how to apply them clinically in the most cost-effective manner. It is now time to appraise whether rapid aneuploidy screening can replace traditional karyotyping when amniocenteses are performed for increased risk of Down's syndrome by maternal serum screening or advanced maternal age in the absence of ultrasound abnormality. The ten most recent studies from the literature within this research theme are reviewed and the pros and cons of this new approach in prenatal diagnosis are discussed, including the suggestion of future studies.

Amniocentesis↗
PubMed2004

Best evidence topic reports. Metoclopramide versus placebo with opioid.

A short cut review was carried out to establish whether metoclopramide reduced nausea and vomiting after the administration of morphine. Altogether 405 papers were found using the reported search, of which one presented the best evidence to answer the clinical question. The author, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of this best paper are tabulated. A clinical bottom line is stated.

Analgesics, Opioid↗