Evaluation of a simple method to assess fetal well-being in antenatal clinic.

To study the feasibility of assessing fetal heart rate (FHR) acceleration by a fetal doptone and fetal movements (FM) as perceived by the mother and observed by the attendant in response to a vibroacoustic stimulus. Baseline FHR and it's response during the first minute after vibroacoustic stimulation was observed by a fetal doptone with a digital display on 317 occasions in 201 pregnancies (81.4% of whom were high risk) during antenatal visits in the third trimester.

Effect of methyldopa and isradipine on fetal heart rate pattern assessed by computerized cardiotocography in human pregnancy.

Objective: The effects of two antihypertensive drugs, methyldopa and isradipine, on fetal heart rate pattern were analyzed by computerized cardiotocography.

Study Design: The first part of the study was a prospective, randomized, controlled trial of 19 women with preeclampsia in the third trimester given 2.5 mg of oral slow-release isradipine twice a day or 250 mg of methyldopa three times a day.

Should assessment of amniotic fluid volume form an integral part of antenatal fetal surveillance of high risk pregnancy?

This study was conducted to evaluate the role of the Amniotic Fluid Index (AFI), used along with nonstress cardiotocography (NST) and fetal acoustic stimulation test (FAST), when required, in prediction of adverse pregnancy outcome. Over a 3-year period 565 pregnant women had antepartum fetal surveillance due to various high risk pregnancy factors and delivered within 7 days of the test. Antepartum fetal surveillance included nonstress cardiotocography together with estimation of AFI.

Induction of labour: does internal tocography result in better obstetric outcome than external tocography.

A prospective randomized study was undertaken to evaluate the benefit of intrauterine catheters in induced labour. Two hundred and thirty nine women who had induced labour were studied. The patients in one group had intrauterine catheters inserted and oxytocin was titrated to achieve the 75th percentile of uterine activity observed in spontaneous normal labour according to parity.

ECG waveform analysis in intrapartum fetal monitoring.

Intrapartum cardiotocography (CTG) has a high false positive rate and, in the absence of facilities for fetal scalp blood sampling, is associated with increased operative deliveries for 'fetal distress'. It is presently possible to obtain a representative fetal ECG signal using the fetal scalp electrode. There is renewed interest in fetal ECG waveform analysis in the hope that it will improve the specificity of detecting intrapartum fetal hypoxia when there is an abnormal fetal heart rate pattern.

Effects of methyldopa on uteroplacental and fetal hemodynamics in pregnancy-induced hypertension.

Objective: Our purpose was to study the effect of methyldopa on uteroplacental and fetal hemodynamics in women with pregnancy-induced hypertension.

Study Design: A prospective study of Doppler ultrasonographic blood flow data before and after 1 week of methyldopa treatment was conducted at the Department of Obstetrics and Gynecology, National University Hospital, Singapore, in 20 women (mean 35 weeks' gestation) with pregnancy-induced hypertension. The main outcome measures were maternal blood pressure, maternal and fetal heart rate, and blood velocity waveforms characterized by the pulsatility index in the fetal ascending aorta, middle cerebral artery, umbilical artery, and maternal uterine and arcuate arteries.

Need for fetal assessment prior to and during external cephalic version. Occurrence of transient cardiac asystole.

We encountered two cases of cardiac asystole for one and three minutes respectively following external cephalic version. We describe the two cases and discuss the necessity for one to be aware of such an event and the possible advantage of performing a fetal heart rate (FHR) recording prior to the procedure and observation of the FHR during the version.

A case report: vesico-rectal fistula with ano-urethral atresia.

Vesico-rectal fistula is a rare congenital abnormality causing severe early second trimester oligohydramnios. Prenatal diagnosis of such a case is reported here. Ultrasound diagnosis could be aided by transabdominal amnio-infusion and, if necessary, fetal intraperitoneal saline installation.

Obstetric admissions to the intensive care unit--a retrospective review.

A five-year retrospective study of obstetric admissions to the Surgical Intensive Care Unit (SICU) in the National University Hospital, Singapore was carried out with the aim of determining the incidence, causes and outcome of these admissions. Most of the patients were admitted following emergency caesarean sections. Obstetric complications was the reason for admission in 56.

Umbilical artery blood flow in intra-uterine growth retarded fetuses and fetal outcome: a study of 102 cases.

The 102 fetuses diagnosed by ultrasound to be asymmetrically growth-retarded had blood flow velocity waveforms of the umbilical artery studied. Sixty-two cases had normal blood flow, 28 had abnormal blood flow but with present end-diastolic flow, 8 had absent end-diastolic flow, and 4 had reversal of end-diastolic flow. Comparison was made between the blood flow status and other biophysical methods of antenatal surveillance and perinatal outcome.

Symptoms and signs with scar rupture--value of uterine activity measurements.

To evaluate the symptoms and signs of scar rupture with special reference to intrauterine pressure measurement a retrospective analysis of labour records of those women who had trial of labour with a previous Caesarean scar in the National University Hospital over a period of 6 years (1985-1990) was carried out. Known symptoms and signs associated with scar rupture, cardiotocographic tracings and fetal and maternal outcome in these patients were studied. Of the 1,018 women with previous Caesarean scar (4.

Training in perinatal care--management of patients in labour.

Training in perinatal care involves many different areas, and care around the time of labour forms a core part of training. Our senior residency programme involves 6 months supervised work in the labour ward. During this period, management of spontaneous, induced and augmented labour, methods of fetal monitoring and pain relief are taught.

Amniocentesis and its complications.

This study was conducted in order to evaluate whether the performance of an experienced operator had any significant influence in reducing the incidence of complications in amniocentesis; 1,459 women had amniocentesis performed under ultrasound guidance; 1,324 were performed by experienced operators and 135 cases by less experienced operators. Complications like fetal loss, blood-stained amniotic fluid, culture failure, multiple needle puncture, leaking liquor, fetal trauma and error in results were compared in the 2 groups. This study demonstrated that amniocentesis performed by an experienced operator decreased the various complications associated with amniocentesis.

The accuracy of catheter-tip pressure transducers for the measurement of intrauterine pressure in labour.

Objective: To assess the reliability of intrauterine pressure measurements in labour with transducer tipped catheters.

Design: Prospective clinical study.

Setting: Delivery ward, National University Hospital, Singapore.

In-utero sound levels when vibroacoustic stimulation is applied to the maternal abdomen: an assessment of the possibility of cochlea damage in the fetus.

Objective: To measure sound pressure level in utero while a vibro acoustic stimulator is applied to maternal abdomen and to calculate whether the estimated effect on fetal cochlea cilia vibration would be hazardous.

Design: Prospective descriptive study.

Setting: Labour ward, National University Hospital, Singapore.

Fetal acidaemia, the cardiotocograph and the T/QRS ratio of the fetal ECG in labour.

Objective: To relate the T/QRS ratio of the fetal electrocardiogram (ECG) to the cardiotocogram (CTG) and fetal pH during labour.

Design: Prospective data collection from selected monitored labours.

Setting: A postgraduate teaching hospital delivery suite.

Vibro-acoustic stimulation does not alter the duration of high and low fetal heart rate variability episodes.

To study the effect of vibro-acoustic stimulation on high and low fetal heart rate (FHR) variability episodes. Prospective control study, in 21 high risk pregnancies between 32 to 39 weeks gestation. FHR pattern was recorded with cardiotocograph (CTG).

Vibro-acoustic stimulation in high-risk pregnancies; maternal perception of fetal movements, fetal heart rate and fetal outcome.

Maternal perception of fetal movement in response to vibro-acoustic stimulation was compared with antenatal fetal heart rate monitoring as a test of fetal well-being in a population of gravidae with high-risk pregnancies (n = 517), admitted to the high-risk ward at Danderyd Hospital, Karolinska Institutet; a total of 2,015 tests were performed. The sensitivity and the specificity of the test compared to the fetal heart rate tracing was 81% and 89% respectively. If the test was performed within 24 hours of delivery, its predictive value for fetal asphyxia (i.

Computerised cardiotocography following vibro-acoustic stimulation.

To study the effect of vibro-acoustic stimulation (VAS) to the mean fetal heart rate (FHR), period of high and low FHR variation, overall variation (msec and bpm) and short term variation (msec). In a prospective study 17 pregnant women between 34-42 weeks gestation admitted to antenatal ward for obstetric complications two 60 min FHR recording was carried out with an interval of 30 min in between recordings. On a random basis the fetus was stimulated by a vibro-acoustic stimulator for 5 sec at the beginning of one of the two 60 min FHR recordings.

Vibroacoustic stimulation and intrauterine sound pressure levels.

The sound pressure level in amniotic fluid generated by vibroacoustic stimulation, assessed with a hydrophone placed close to the fetal head, was studied in 16 subjects. The mean recorded sound pressure level was 115 dB and the highest level was 129 dB. The range of the background noise was 63.

Reliability of intrauterine pressure measurements.

The reliability of intrauterine pressure measurements was studied by placing two catheters in the same uterus in women in labor. Nineteen parturients were studied, five with two Intran I catheters in different pockets of amniotic fluid, five with two Intran II catheters in different pockets, and nine with two Intran II catheters in the same pocket of amniotic fluid. Among 1429 contractions studied, the catheters showed differences of pressure of less than 5 mmHg in 86% of contractions and of less than 10 mmHg in 94%.

No evidence of hearing loss due to fetal acoustic stimulation test.

The fetal acoustic stimulation test is used increasingly for fetal assessment. To evaluate the possibility of acoustic trauma, 465 children who had been exposed to vibroacoustic stimulation in utero were screened at 4 years of age for high-frequency hearing loss. A hand-held audiometer with test tones at 25 dB for 1000 and 4000 Hz was used because responses at this level indicate hearing within normal limits for middle and high frequencies.