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Biomedical subjects

S Chua

Publications and source records attributed to S Chua.

At least 55 records · Page 3Linked to original sources
PubMed1996

A comparison between visual estimation and laboratory determination of blood loss during the third stage of labour.

A prospective study was conducted to compare the accuracy of visual estimation of blood loss (EBL) at delivery with laboratory determination of measured blood loss (MBL). It showed that EBL tends to be clouded by the conventional teaching that blood loss at delivery is usually between 200 to 300 mL. Women with MBL up to 150 mL were overestimated and the best correlation was in women with MBL between 150 to 300 mL. There was a tendency to underestimate blood loss when the MBL was between 301 to 500 mL. Of the 9 women with a primary postpartum haemorrhage, only one was correctly diagnosed as such and 3 women were estimated to have blood losses of at least 500 mL but the measured blood losses were all lower. It was concluded that visual estimation of blood loss is inaccurate, especially at the extremes of MBL and that primary postpartum haemorrhage is not detected by visual estimation of blood loss, unless there are associated signs of haemodynamic instability.

Female↗
PubMed1996

Correlation of total uterine activity to blood loss in the third stage of labour.

In 27 women, uterine activity in the third stage of labour was correlated with blood loss measured quantitatively during the same period of time. Myometrial activity was reflected by total intrauterine pressures measured using a Gaeltec catheter tipped pressure transducer inserted transcervically within 5 min of delivery of the placenta. Blood loss over the same 2-hour period was collected on absorbent paper and measured in the laboratory by colorimetric measurement of the haemoglobin content. As total uterine activity in the third stage of labour decreases total blood loss increases, but there is a poor correlation of uterine activity to total blood loss over the same period of time, probably because of biological variations in myometrial activity in normal women.

Female↗
PubMed1996

Search for the most predictive tests of fetal well-being in early labor.

The aim of the study was to evaluate the admission CTG alone and in combination with the following tests: fetal acoustic stimulation test (FAST), maternal perception of sound provoked fetal movement (mpSPFM), amniotic fluid index (AFI), and umbilical artery doppler studies in early labor. 1092 singleton pregnancies in cephalic presentation, and with intact amniotic membranes at 37 weeks gestation or more, were admitted in early labor to the labor ward at the National University Hospital, Singapore. Admission tests were performed, and labor managed according to established labor ward protocol. Of all the tests performed, only the results of the admission CTG and color of the amniotic fluid were known to the obstetrician. If the admission CTG is normal, AFI is > 5 cm and there is an acceleratory responses to FAST the incidence of fetal distress is low. In the presence of a reactive admission CTG and in the absence of thick meconium, fetal heart rate response to FAST and the AFI provided a better selection of the high risk fetus that would require closer monitoring or early delivery. When the admission CTG was suspicious, FAST, AFI, and blood flow velocity waveform studies may allow more confident prediction of the ability of the fetus to withstand the stresses of labor.

Acoustic Stimulation↗
PubMed1996

Congenital abnormalities and pregestational diabetes mellitus in pregnancy.

Despite falling perinatal mortality rate, congenital malformation remains the major cause of mortality in infants of mothers with established diabetes. The perinatal mortality rate in this group of infants is 5 times the overall perinatal mortality rate in this hospital. It is well established that pre-pregnancy counselling and maintenance of euglycaemia during the periconception period are the keys to prevention of congenital malformation. We are able to offer pre-pregnancy counselling to 29% of our diabetic mothers who are diagnosed to have pregestational diabetes mellitus only after the 6 weeks postnatal oral glucose tolerance test. Even in the known established diabetes mellitus, 95% of the patients were first seen after the period of organogenesis (> 8 weeks). This could explain our high congenital malformation rate of 15.7%.

Adult↗
PubMed1996

Gestational diabetes: obstetric and neonatal outcome in 411 cases.

AIM: To study the obstetric and neonatal outcome of women with gestational diabetes mellitus. METHODS: Four hundred and eleven (411) women with gestational diabetes mellitus were studied retrospectively. The control group was 3,391 non-diabetic women delivered in the same period. RESULTS: Women with gestational diabetes mellitus had a significantly higher incidence of pregnancy-induced hypertension, and more were likely to present with malpresentation in labour. They had a higher incidence of surgical induction and an increased incidence of elective and emergency Caesarean section rate compared to controls. The neonatal outcome was excellent. The perinatal morbidity and mortality were similar to the non-diabetic controls. CONCLUSION: The excellent outcome of the women with gestational diabetes mellitus in this study is attributed to tight control of blood glucose level and close attention given to this group of patients.

Delivery, Obstetric↗
PubMed1995

Premature rupture of membranes in nulliparas at term with unfavorable cervices: a double-blind randomized trial of prostaglandin and placebo.

OBJECTIVE: To determine whether the use of a prostaglandin (PG) E2 3-mg pessary followed by a delay of 12 hours before stimulation of labor with oxytocin improves obstetric outcome compared with the use of a placebo pessary. METHODS: One hundred fifty-five nulliparas at term with poor cervical scores (modified Bishop score below 6 of 10) and premature rupture of membranes (PROM) were recruited for this double-blind, placebo-controlled randomized trial. On admission to the study, either a PGE2 pessary or an identical-appearing placebo pessary was inserted into the posterior fornix. If labor did not start in the next 12 hours or if symptoms and signs of infection were evident, labor was induced with oxytocin infusion. Assignment was unblinded at the end of the study, and details of the labor and maternal and neonatal outcome in women who received a PG pessary were compared with those who received a placebo pessary. RESULTS: Women receiving a PG pessary were significantly less likely to require stimulation of labor at the end of 12 hours than were those given a placebo pessary (37 versus 58%, P = .002). The mean time between admission to study and delivery was significantly shorter in the PG group compared with the placebo group (15 versus 19 hours, P = .01). The rate of cesarean delivery was not statistically different in the two groups (13.9% with PG versus 15.8% with placebo). CONCLUSION: In nulliparas with poor cervical scores who present with PROM at term and no evidence of infection or obstetric complications, use of a PGE2 pessary resulted in more women establishing labor earlier, with a resultant reduction in the admission-to-delivery interval, compared with the use of a placebo pessary. The cesarean delivery rates in the two groups were similar, and there were no significant differences in neonatal outcome.

Cervix Uteri↗
PubMed1995

Continuous maternal glucose infusion during labor: effects on maternal and fetal glucose and lactate levels.

Fetal and neonatal glucose and lactate levels and acid-base balance after continuous maternal infusion of 5% dextrose at 180 mL/h (9 g/h) was compared with 0.9% saline solution in a prospective, randomized study from selected monitored labors. An infusion of 5% dextrose produced significantly increased glucose levels in maternal (p < 0.01), cord artery (p < 0.01), and cord vein (p < 0.001) blood. An increased maternal insulin level was also present (p < 0.05), but no differences in cord insulin levels were observed. beta-Hydroxybutyrate was lower in maternal (p < 0.05) and cord vein (p < 0.01), but not in cord artery blood, after maternal dextrose infusion. No significant changes occurred in blood lactate levels between the two groups in either mother, fetus, cord, or neonate. Acid-base balance in cord blood did not differ between the two groups. Maternal infusion of 5% dextrose at 180 mL/h (9 g/h), compared with saline solution, produces higher glucose levels in both mother and fetus, but increased insulin concentrations only in the mother. Dextrose infusion also lowers beta-hydroxybutyrate in maternal and cord vein blood. No differences were seen in lactate levels or cord acid-base balance. Both regimens seem safe according to risks for lactacidosis and neonatal hypoglycemia in the normoxemic, normal size fetus.

3-Hydroxybutyric Acid↗
PubMed1995

Identification of new members of a carbohydrate kinase-encoding gene family.

In a sequence database search using the human glycerol kinase-encoding sequence (HUMGLYKINB) as a query, we identified six previously unidentified carbohydrate kinase sequences. Five of the six newly identified sequences appear to be known types of carbohydrate kinases, four are glycerol kinases and one is a gluconokinase. The sixth newly identified sequence, the Caenorhabditis elegans gene, CER08D7.7-CEF59B2.1, shows similarity to the family of carbohydrate kinases including other glycerol kinases, xylulokinases, gluconokinases, ribulokinases, rhamnulokinases, and fucokinases. A phylogenetic comparison of this newly identified Caenorhabditis elegans gene with the other members of the carbohydrate kinase family demonstrated that this sequence cannot be assigned to one of the known classes of carbohydrate kinases.

Amino Acid Sequence↗
PubMed1995

Prelabour rupture of membranes to delivery interval related to the incidence of maternal and neonatal infection.

OBJECTIVE: To assess the infectious morbidity associated with prelabour rupture of membranes (PROM) to delivery interval, and the incidence of maternal and neonatal infection in a population managed by either immediate stimulation or by overnight conservatism. METHOD: A retrospective study of 117 women admitted with PROM to the labour ward in the National University Hospital, Singapore, in the period between June 1990 and May 1991, and who were managed by immediate stimulation or by stimulation after overnight conservatism. Statistical analysis was performed using Chi-square and Student's t-test. RESULTS: More than one third of infants whose mothers had ruptured membranes for > 48 hrs had signs of neonatal infection, compared with an incidence of 8.8% and 8.9%, respectively for those with an interval of < 12 hrs and 12-24 hrs between PROM to delivery. Group B streptococcal infection was a major cause of neonatal infectious morbidity. Clinical evidence of maternal infection occurred in 3 of the 117 women; these patients had an interval between rupture of membranes and delivery of between 24-76 hrs. CONCLUSIONS: Prolongation of PROM to delivery interval for > 48 hrs increases the incidence of infection. Conservative policy of management of PROM at term should aim to deliver the babies < 48 hrs after PROM. The difference in maternal and neonatal infection rates were not significant in the group treated with a policy of overnight conservatism compared with the group in whom labour was stimulated immediately on admission.

Bacterial Infections↗
PubMed1995

A randomized controlled study of prostaglandin 15-methyl F2 alpha compared with syntometrine for prophylactic use in the third stage of labour.

A randomized controlled study of 112 women with singleton pregnancies at term, and no antenatal complications, admitted in spontaneous labour were randomized to receive either an intramuscular injection of 0.5 mg of Syntometrine or an intramuscular injection of 125 ug of prostaglandin 15-methyl F2 alpha at delivery of the anterior shoulder of the baby. Blood lost in the first 2 hours, and subsequent 22 hours postdelivery were collected separately and measured by colourimetric measurement of haemoglobin content. Other parameters in the third stage were measured, including need for transfusion of blood or blood products, length of the third stage, and change in haemoglobin concentration before and 24 hours after delivery. The incidence of side-effects with administration of either prostaglandin 15-methyl F2 alpha or Syntometrine were documented. The prophylactic use of intramuscular prostaglandin 15-methyl F2 alpha (Carboprost) in the active management of the third stage of labour gave similar results to prophylactic intramuscular Syntometrine in terms of length of the third stage of labour, incidence of postpartum haemorrhage and total blood loss in the first 2 hours and subsequent 22 hours after delivery. However it has the disadvantage of higher cost, as well as statistically significant increase in the incidence of profuse and frequent diarrhoea. Based on these results intramuscular injection of prostaglandin 15-methyl F2 alpha offers no advantage over intramuscular Syntometrine for routine prophylactic use to reduce blood loss in the third stage of labour.

Carboprost↗
PubMed1995

Atrial septal motion in effusive--constrictive pericarditis: transesophageal echocardiographic study and hemodynamic correlation.

Transesophageal echocardiography was performed in 7 patients with effusive-constrictive pericarditis to analyze atrial septal motion(ASM). In 3 patients, the ASM was found to be normal with atrial septum (AS) moving toward the right atrium from ventricular mid-systole to early-diastole and toward the left atrium from mid-diastole to early-systole. Respiration had little effect on the ASM. In 2 patients, a brisk inversion of ASM toward the left atrium at ventricular early-to-mid systole was noted during inspiration. In the other 2 patients, a sustained ASM toward the left atrium during ventricular systole was found. In 4 of these 7 patients, hemodynamic studies were performed simultaneously with the transesophageal echocardiography. The ASM reflected the pressure gradient between the left atrium (as measured by pulmonary arterial wedge pressure) and the right atrium. The augmented ASM toward the left atrium occurred as left atrial pressure decreased markedly during inspiration. In conclusion, the ASM in patients with effusive-constrictive pericarditis showed 3 patterns: normal, sustained systolic motion toward the left atrium and a brisk systolic displacement toward the left atrium during inspiration. The ASM reflects changes in the interatrial pressure gradient.

Adult↗
PubMed1995

Obstetric outcome of pregestational diabetic pregnancies.

This retrospective study examined the obstetric and neonatal outcome in 23 pregestational diabetic pregnancies. The incidence of congenital malformations and mortality in infants of diabetic mothers was increased compared to the control population. Late booking for antenatal care and poor glycaemia control are probably the reasons for this high incidence. There was also a significantly higher preterm delivery and Caesarean section rate in the pregnancies complicated by pregestational diabetes. The neonatal morbidity was also higher than the controls in terms of jaundice, hypoglycaemia, respiratory distress syndrome and admissions to neonatal intensive care unit. Only with preconception counselling and tight glycaemia control in the periconception period and throughout pregnancy can we expect a drop in the complication rates in pregestational diabetic pregnancies.

Adult↗
PubMed1995

Glycosylated haemoglobins in women with low risk for diabetes in pregnancy.

Glycosylated haemoglobin levels (HbA1) were determined in 489 normal pregnant Singaporean women, attending a diabetic screening programme using a 50g glucose challenge test. All subjects had no risk factors for diabetes mellitus nor a history of previous gestational diabetes. They were selected when the 1h 50g glucose challenge (GCT) is < 6.66 mmol/l or a 2h post-glucose level of < 7.77 mmol/l (a 75g OGTT is repeated within a week of an abnormal GCT). Another 18 subjects with normal OGTT but did not have a 50g glucose challenge done were also included in the study. Mean and normal range (2 SD) of HbA1 levels in all subjects were 4.64% and 3.66-5.62%, respectively. Mean HbA1 levels also varied with gestation and ethnic group. The HbA1 appeared to be low at early gestation with nadir at 21-24 weeks and thereafter returned to initial levels at term. In Chinese, mean HbA1 levels, random plasma glucose and 1h glucose challenge were significantly higher than those of the Malays but not the Indians. In referring to these levels, the variation within gestation and ethnic group must also be considered.

Adult↗
PubMed1995

Genital Group B Streptococcus carriage in the antenatal period: its role in prom and preterm labour.

Of 326 high vaginal swabs taken during the antenatal period, Group B Streptococcus (GBS) was isolated from the birth canal in 46 women, giving a carrier rate of 14.1%, which is within the often quoted range of between 5% - 25% in different parts of the world. Carriage rates were similar at different gestations. In a subgroup of 34 women, 2 swabs taken at least 5 weeks apart yielded results which were discordant in over one fifth of the time. This knowledge of the natural history of GBS carriage questions the practice of treating asymptomatic carriers of GBS in the antenatal period to prevent transmission of GBS to the neonate. The group of women with positive swabs in the antenatal period did not have a significantly higher incidence of preterm labour and/or prelabour rupture of membranes (PROM) compared with the group of women with negative swabs. Routine screening of the antenatal population for GBS carrier status prior to 32 weeks gestation may not identify women at high risk of PROM or preterm labour.

Adult↗