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Tze Kin Lau

Publications and source records attributed to Tze Kin Lau.

At least 37 records · Page 2Linked to original sources
PubMed2005

Maternal experience of pain during external cephalic version at term.

BACKGROUND: This study was designed to investigate maternal pain perception during external cephalic version (ECV). METHODS: This prospective study included 97 pregnant women with singleton breech presentation at or above 36 weeks of gestation undergoing ECV. No analgesia or anesthesia were used during ECV. The women were asked to rate the degree of pain on a 10-cm visual analog scale after ECV. RESULTS: Ninety-eight ECVs were performed and the overall success rate was 66%. The median pain score was 5.7 (interquartile range 2.7-6.8). The visual analog pain score was significantly lower among those with a successful ECV than those with a failed procedure (median score 4.6 vs. 6.8, p < 0.001). Similarly, those procedures rated as easy by the operator were associated with a significantly lower pain score (3.4 vs. 6.4, p < 0.001). However, the pain score was not found to be related to the operator, parity or placental site. Among the five subjects with a pain score of 8.5 and beyond, the ECV procedure was still successful in four (80%). CONCLUSION: ECV performed without analgesia was associated with a moderate degree of pain that was well tolerated by the majority of patients because of its short duration.

Adult↗
PubMed2005

Fetal hemodynamic changes after amniotomy.

BACKGROUND: The aim of the study was to assess fetal vascular blood flow after amniotomy. METHODS: This was a prospective observational study. Thirty-five women with singleton pregnancy beyond 36 weeks of gestation, who underwent amniotomy, were recruited. The pulsatility indices of the fetal middle cerebral artery (MCA), the renal artery, and the ductus venosum were measured before and 30 min following amniotomy. The changes in pulsatility index were compared by means of Wilcoxon signed rank test. RESULTS: There was a significant reduction in pulsatility indices of the MCA (median reduction: 0.23; interquantile range (IQR): -0.04, 0.4) and the renal artery (median reduction: 0.12; IQR: -0.12, 0.54) after amniotomy. However, there was no obvious change in the ductus venosum (median reduction: 0.00; IQR: -0.06, 0.1). CONCLUSIONS: Amniotomy is associated with significant reduction in the impedance of the fetal MCA and the renal artery. The former may be a result of fetal stress response and the latter could be related to the release of vasoactive substances after amniotomy.

Adult↗
PubMed2005

Impact of hypertensive disorders of pregnancy at term on infant birth weight.

This study was performed to investigate the impact of hypertensive disorders of pregnancy at term on neonatal birth weight. All singleton live births delivered between 37 and 42 weeks of gestation complicated by hypertensive disorders over a 7-year period (n = 362) was compared to 34 783 uncomplicated singleton deliveries in the same period. The individualized gestation-related optimal weight (GROW) was calculated for each individual case adjusted for the effects of maternal booking weight, height, parity, gestation at delivery, and fetal sex. Small-for-gestational-age (SGA) was defined as a birth weight less than the 10th percentile of the GROW. The incidence of SGA babies was significantly higher in subjects with preeclampsia and eclampsia than in control subjects (24.6 versus 11.3%; odds ratio = 2.55; 95% CI: 1.84, 3.55). Preeclampsia significantly reduced fetal birth weight by 130 g or 4.3%. Those with eclampsia on average had a neonatal birth weight 349 g or 11.0% below that of the GROW. In contrast, there was no significant difference in the incidence of SGA babies or degree of deviation from GROW between those with or without gestational hypertension.

Adult↗
PubMed2005

Sleep disturbances in Chinese pregnant women.

In a prospective study of 247 pregnant Chinese women, the prevalence of sleep disturbances across pregnancy has been assessed using a set of validated questionnaires including the Sleep and Health Questionnaire (SHQ) and the Epworth Sleepiness Scale (ESS). The frequency of self-reported snoring increased from 29.7% in the first trimester to 40.5% and 46.2% in the second and third trimesters, respectively, with an increase in the prevalence of moderate or severe snoring from 1% in the first trimester to 7.2% in the third trimester (P < 0.01). There was a higher frequency of moderate to severe snoring intensity among subjects with BMI >or=25 compared with those with BMI <25 kg/m(2) in the third trimester (20.8%vs 5.3%, P < 0.01). Subjective sleepiness, as determined by the ESS, increased significantly from 8.6 to 9.4 and 9.6 in the first, second and third trimesters, respectively.

Adult↗
PubMed2005

Effect of prostaglandin E2 for cervical priming on fetal hemodynamics.

OBJECTIVE: To assess the effect of the prostaglandin E2 (PGE2) on fetal vascular blood flow during cervical priming. STUDY DESIGN: In a prospective, observational study, 32 pregnant women > or =37 weeks of gestation requiring PGE2 for induction of labor were recruited. The resistance indices (RIs) of umbilical artery, middle cerebral artery, renal artery and ductus venosum were measured before, 2 and 4 hours after insertion of a PGE2 vaginal pessary. RESULTS: There were no significant changes in RIs of various fetal vessels during cervical priming with PGE2. CONCLUSION: There was no significant change in fetal hemodynamics after vaginal prostaglandin administration. This finding provides further evidence to support the safety of prostaglandin for normal fetuses.

Administration, Intravaginal↗
PubMed2004

Prediction of successful vaginal delivery in women undergoing external cephalic version at term for breech presentation.

OBJECTIVE: The aim of this study is to evaluate the clinical and sonographic predictors of ultimate successful vaginal delivery in women undergoing external cephalic version. STUDY DESIGN: The study population consisted of women with external cephalic version performed at or after 36 weeks of gestation. They were randomized into group A or B, each consisted of half of the total study population. Logistic regression was performed on group A to identify the significant independent variables in predicting successful cephalic vaginal delivery, which were used to construct a prediction model. The derived regression model was then tested in group B to assess its accuracy. RESULTS: The study included 407 pregnancies. Maternal weight (kg) at the time of version, maternal height (cm), multiparity, engagement of fetal presenting part, and fetal head palpable were significant independent variables of successful version and vaginal delivery (regression coefficients are: -0.084, 0.085, 1.752, -1.271, and 0.725, respectively). A prediction model was constructed based on these independent variables. The weighted average of the overall accuracy in predicting success or failure of version and vaginal delivery was 70.9%. The regression model was then applied to study group B. Using 0.50 as the cutoff value, the sensitivity, specificity, positive, and negative predictive values were 75.4, 58.8, 73.7, and 61.0%, respectively. CONCLUSION: A regression model constructed based on clinical variables failed to provide an accurate predictive tool of successful external cephalic version and vaginal delivery. However, in women who are equivocal about external cephalic version, a high prediction of success would be encouraging.

Adult↗
PubMed2004

Attitudes towards termination of pregnancy among Hong Kong Chinese women attending prenatal diagnosis counselling clinic.

OBJECTIVE: To investigate the attitudes towards termination of pregnancy (TOP) among Hong Kong Chinese women attending the prenatal diagnosis counselling (PDC) clinic under three circumstances: (1) normal fetus, (2) fetal chromosomal anomalies, and (3) fetal abnormalities diagnosed after 24 weeks of gestation, and to determine the association between the attitudes and demographic factors. METHODS: One hundred and twenty-two women were interviewed using a structured questionnaire. RESULTS: Over 50% of our women viewed it as their right to choose an abortion in early pregnancy and only 28.7% agreed that the doctor has the right to make the final decision. Approximately 90% would choose TOP for lethal chromosomal abnormalities and Down syndrome while about 50% would do so for Klinefelter or Turner syndromes. Over 80% were of the opinion that women should be given the right to choose TOP for lethal congenital malformation as well as for Down syndrome after 24 weeks of gestation. This figure dropped to 55.7% for non-lethal structural malformation that requires postnatal treatment. Religious background was a significant factor for a negative attitude towards TOP. CONCLUSION: Our data suggest that our women who attended the PDC clinic had an open attitude towards TOP for fetal abnormalities in general.

Abortion, Induced↗
PubMed2004

Human decidual production of hepatocyte-growth factor is not influenced by trophoblastic invasion in vivo.

OBJECTIVE: To evaluate and compare production of hepatocyte growth factor (HGF) from human first-trimester implantation-site decidua (decidua basalis) and nonimplantation site decidua (decidua parietalis), and hence to determine whether human trophoblast invasion in vivo is associated with increased decidual HGF production. DESIGN: Controlled prospective study. SETTING: University hospital-based study. PATIENT(S): Ten women undergoing first-trimester termination of singleton pregnancy for psychosocial reasons without preexisting medical or gynecologic diseases. INTERVENTION(S): Decidual samples surgically excised and processed for paraffin-embedded immunohistochemistry and for reverse transcription-polymerase chain reaction (RT-PCR) studies. MAIN OUTCOME MEASURE(S): Protein and mRNA production in decidua basalis and decidua parietalis by immunohistochemistry and RT-PCR, respectively. RESULT(S): No statistically significant difference was found between decidua basalis and decidua parietalis in HGF protein or mRNA production. Immunohistochemical analysis (n = 9) showed a mean score of 3.28 +/- 2.37 for decidua basalis and 3.61 +/- 2.66 for decidua parietalis. Semiquantitative analysis of HGF mRNA expression between the two sites showed no statistically significant difference (n = 10) CONCLUSION(S): Human decidual production of HGF is not influenced by trophoblastic invasion in vivo.

Decidua↗
PubMed2004

Cord blood acid-base status at delivery after successful external cephalic version.

BACKGROUND: This study was designed to evaluate whether cord blood acidosis is more likely in infants born after successful external cephalic version. METHODS: This retrospective cohort study included 89 singleton deliveries with successful version performed over a 2-year period. Their cord blood acid-base parameters were compared to 89 pregnancies with spontaneous cephalic presentation (control group). RESULTS: There was no significant difference between the version and control groups in birthweight and Apgar scores. There was no difference between the version and control groups in cord arterial pH (7.26 vs. 7.26), arterial pCO(2) (7.04 vs. 7.09 kPa), arterial pO(2) (2.34 vs. 2.59 kPa), arterial base excess (-5.59 vs. -5.64 mmol/L), venous pH (7.32 vs. 7.33), venous pCO(2) (5.73 vs. 5.63 kPa), venous pO(2) (3.86 vs. 3.84 kPa), or venous base excess (-5.03 vs. -5.12 mmol/L). There was also no significant difference in the number of fetuses with cord arterial pH <7.20 between the two groups. CONCLUSION: Neonates delivered after successful external cephalic version are not more likely to be born with acidosis. Our study provides further support for the safety of external cephalic version for term breech pregnancies.

Acidosis↗
PubMed2004

External cephalic version induced fetal cerebral and umbilical blood flow changes are related to the amount of pressure exerted.

OBJECTIVE: To correlate the applied pressure during external cephalic version with the changes in fetal middle cerebral arterial and umbilical arterial flow before and after the procedure. DESIGN: A prospective observational study over a two-year period. SETTING: External cephalic version was performed in a university hospital. POPULATION: Sixty-nine women with singleton breech-presenting pregnancy at or above 36 weeks of gestation undergoing external cephalic version. METHODS: During external cephalic version, the operator wore a pair of pressure-sensing gloves which had thin piezo-resistive sensors positioned on the palmar surface. During each version procedure, real-time pressure readings were recorded from all sensors, and then analysed with a computer program. The amount of pressure applied over time was presented by pressure-time integral. The pulsatility indices of both fetal middle cerebral artery and umbilical artery before and after external cephalic version were measured. The changes of pulsatility indices of both middle cerebral artery and umbilical artery were presented as a ratio of the post-external cephalic version pulsatility indices to pre-external cephalic version pulsatility indices, denoted by middle cerebral artery pulsatility index ratio and umbilical artery pulsatility index ratio, respectively. The statistical correlation between pressure-time integral and middle cerebral artery pulsatility index ratio and umbilical artery pulsatility index ratio are analysed using Pearson's correlation test. MAIN OUTCOME MEASURES: Changes in pulsatility indices of fetal middle cerebral and umbilical arteries and fetal heart rate after external cephalic version. RESULTS: The overall success rate of external cephalic version was 77%. There was a significant negative correlation between pressure-time integral and both middle cerebral artery pulsatility index ratio (P= 0.001) and umbilical artery pulsatility index ratio (P= 0.012). When women were categorised according to placental site, pressure-time integral was negatively correlated with middle cerebral artery pulsatility index ratio only when the placenta was posteriorly located (P= 0.003), and with umbilical artery pulsatility index ratio only when the placenta was laterally located (P= 0.03). CONCLUSIONS: The greater the force applied during external cephalic version, the greater the reduction in pulsatility indices of middle cerebral artery and umbilical artery, indicating an increase in blood flow through these arteries. The increase in cerebral blood flow after external cephalic version is more prominent when the placenta is lying posteriorly, while the increase in umbilical flow is more prominent when the placenta is lying laterally. These findings suggest that the vascular changes probably represent a direct effect of force exerted on the fetal head and the placenta.

Adolescent↗
PubMed2004

Obstetric outcomes after cervical ripening by multiple doses of vaginal prostaglandin E2.

AIM: The study was designed to investigate the delivery outcome in women who required vaginal prostaglandin E2 for cervical priming prior to labor induction. MATERIALS AND METHODS: This retrospective cohort study included all singleton term deliveries that required labor induction over a 3-year period. Incidence and indications of obstetric interventions were compared among women who required different doses of vaginal prostaglandin E2 for cervical priming and who had induction by amniotomy and oxytocin infusion. RESULTS: Of 706 deliveries, 411 had favorable Bishop's scores and no vaginal prostaglandin E2 for cervical priming was required (group A); 268 required one or two doses of vaginal prostaglandin E2 for cervical priming (group B); and 27 required three or more doses (group C). The incidence of cesarean section was significantly higher in group C (48.1%) than in group A (19.0%) and group B (16.4%). The difference remained statistically significant when primiparous and multiparous women were analyzed separately. The risk of obstetric intervention was particularly high in primiparous women in group C (58.8% required emergency cesarean section and 23.5% had instrumental delivery). There was an increased frequency of all major indications for cesarean section in group C. CONCLUSION: The risk of emergency cesarean section was higher in women who required more than two doses of vaginal prostaglandin E2 for cervical priming compared to induction by one or two doses of vaginal prostaglandin E2 or by amniotomy and oxytocin infusion. These women should be informed regarding the high risk of intrapartum cesarean section, and the option of alternative methods of induction or elective cesarean section should be made available.

Administration, Intravaginal↗
PubMed2003

Cord blood thyroid-stimulating hormone level in high-risk pregnancies.

OBJECTIVE: To evaluate the effect of various antepartum conditions on cord blood thyroid-stimulating hormone (TSH) level. STUDY DESIGN: The study group consisted of 24,892 consecutive singleton deliveries over a period of 4 years. The effect of preeclampsia, glucose intolerance, maternal medical diseases, and antepartum hemorrhage of unknown origin (APHUO) on cord blood TSH level were assessed by univariate analysis and linear regression. RESULTS: After controlling for potential confounders, there was a significant independent association between cord blood TSH level and preeclampsia (P=0.043), glucose intolerance (P=0.015), and maternal medical diseases (P=0.022). Antepartum hemorrhage of unknown origin was not associated with a higher cord blood TSH level. CONCLUSION: Cord blood TSH level was significantly elevated in various adverse antepartum conditions. This may be related to the placental insufficiency and fetal hypoxia commonly found in these high-risk pregnancies.

Female↗
PubMed2003

Quantification of contact surface pressure exerted during external cephalic version.

BACKGROUND: The amount of force exerted on the uterus and fetus during external cephalic version (ECV) may be associated with fetal effects or complications. We have designed an instrument to quantify the contact pressure exerted during the performance of ECV, as an indirect measurement of the applied force. METHODS: We have designed a pair of custom-made gloves. Each glove contains 16 piezo-resistive sensors positioned on the palmer surface of the fingers, thenar and hypothenar areas. Pressure readings were recorded simultaneously from all sensors every 0.22 s during each version procedure. Each recording was analyzed with a computer program written according to specified algorithms to ascertain the number of attempts in a version operation, and the duration and pressure changes of each attempt during the operation. RESULTS: Ten subjects having a singleton breech presentation at term underwent an operation of ECV. The number of attempts of version in each operation ranged from one to four. The median pressure-time integral and the duration of an attempt were 19,227 mmHg s (range 5089-42,597 mmHg s) and 42.5 s (range 11.9-80.3 s), respectively. The median pressure-time integral of a whole version operation was 38,110 mmHg s (range 5089-107,511 mmHg s). Subjects with a failed version operation received a higher pressure-time integral (p < 0.05). The number of attempts of each operation was accurately identified by the program. CONCLUSIONS: Measurement of force applied during ECV can be quantified indirectly in terms of contact surface pressure. The indirect measurement of the applied force may further improve the safety of this procedure by preventing excessive use of force by the operator.

Adult↗