Prenatal ultrasound diagnosis in Thailand.

Ultrasound technology has been extensively employed in obstetric and gynecologic practice for several decades. It has been used not only in gestational age estimation, placental location, amniotic fluid assessment but also in antenatal diagnosis of fetal abnormalities of various systems. The incidence of Congenital Heart Disease (CHD) is currently estimated to be 8 to 9 out of every 1,000 live births. Congenital heart disease is thought to be a multifactorial disorder in over 90% of the cases. Pioneer studies on the ultrasound investigation of the heart were reported in the early 1970s. Since the introduction of high resolution real-time ultrasound in the late 1970s, reports on ultrasound assessment of fetal cardiac anatomy and function have been appearing with increasing frequency in both the obstetric and cardiologic literature. At present, fetal echocardiography is a well established technique for the prenatal diagnosis of CHD. However, the distribution of the technique is still limited as it requires both a very experienced operator and meticulous scanning. Screening the entire obstetric population does not appear possible at present. Therefore fetal echocardiography is as necessarily directed toward selected pregnancies carrying a higher-than-normal risk of fetal cardiac anomalies. The progressive developments in cardiac ultrasound during the past two decades have substantially altered the practice of perinatologists, obstetricians and cardiologists. Total cardiac ultrasound studies are now becoming the primary armamentarium in the diagnosis of fetal congenital heart diseases. Since a 92% sensitivity of 4-chamber view in screening fetal heart diseases was first reported in 1987, 4-chamber view has been widely recommended for routine use in fetal sonographic examinations. Recent studies have demonstrated somewhat variable results and have suggested incorporation of the out flow should thoroughly understand the advantages and limitations of fetal cardiac scanning especially the 4-chamber view in order that the appropriate information and management plan can be offered to the patients. Fetal cardiac scanning is well recognized as one of the most tedious scanning of all fetal organ systems. With a tremendous advancement in ultrasound resolution including color imaging capacity several kinds of fetal cardiac anomalies could be diagnosed antenatally which inevitably allows more proper management plan for couples engaged in these.

Doppler umbilical artery flow velocity waveforms in pregnancies complicated by major fetal malformations.

A pulse-wave Doppler ultrasound was used to identify fetal umbilical cord and to obtain flow-velocity waveforms. The umbilical artery Doppler indices were determined in 34 fetuses with major congenital malformations between 20 and 38 wks' gestation. Reference ranges of fetal umbilical artery systolic and diastolic (S/D) ratio, pulsatility index (PI) and resistance index (RI) with gestation were constructed from a cross-sectional study of 331 appropriate for gestation age fetuses of 16 to 41 wks' gestation. The records were reviewed to determine the changes associated with fetal malformation. Twenty five of 34 patients with major congenital anomalies showed high S/D ratio, PI and RI in waveforms taken from the umbilical artery. All fetuses with chromosomal aneuploidy (10 cases) had high umbilical artery S/D ratio, PI and RI. It appears that a fetal mechanism may determine the changes in the umbilical placental circulation resulting in an umbilical artery pattern of high flow resistance in fetuses with congenital anomalies.

Intrauterine-pressure studies in Thai nulliparous labour: the use of catheter-tip pressure transducer.

Uterine activity was studied in 35 nulliparous Thai women who were in the active phase of spontaneous labour, and who were delivered vaginally without supplementary oxytocin or assisted delivery. A catheter-tip pressure transducer coupled with a uterine activity integrator was used to measure and quantitate uterine activity. Progression of normal labour was defined as labour progressing along the Friedman's curve in the active phase. In nulliparous Thai women, the minimum level of uterine activity likely to be associated with labour progress was 322 kPas/15 min at 3 cm cervical dilatation. The mean and median levels in the active phase of normal labour were 1,075.6 and 952.0 kPas/15 min, respectively. There was a weak correlation (R = 0.3) between an increasing cervical dilatation and uterine activity.

Pelvic actinomycosis in pregnancy: a case report and review of the literature.

The first reported case in Thailand of pelvic actinomycosis during pregnancy is presented. It occurred in a 38-year-old Thai female with a history of IUD wearing for 2 years until the symptoms of intermittent lower abdominal pain. She had a history of postcoital bleeding at 16 weeks' pregnancy and bleeding per vagina during labor at 40 weeks' pregnancy. Speculum examination showed an irregular, friable, easily bleeding mass (3-4 cm in diameter). The specimens of the mass at the posterior fornix were obtained for culture and pathological examination. Right tubo-ovarian complex measured 10 x 4 x 4 centimeters in diameter, extending through the cul-de-sac to the vaginal canal at the posterior fornix, was identified during exploratory laparotomy. Low transverse cesarean section was performed. The pathological diagnosis was actinomycosis of right fallopian tube and ovary. The patient was treated with tetracycline.

Maternal perception of sound-provoked fetal movement as a test of antepartum fetal wellbeing.

Maternal perception of sound-provoked fetal movement test was studied on 506 occasions in 443 women with obstetric or medical antenatal risk factors after 26 weeks gestation. The response was compared with a nonstress test (NST) performed immediately after a three-second vibroacoustic stimulation with an electronic artificial larynx. A positive response to sound stimulation, recorded as a fetal movement by the mother, occurred on 497 occasions (97.3%) and was accompanied by a reactive NST on 484 occasions; giving a specificity of 99.6 per cent and a negative predictive value of 97.4 per cent. An inconclusive or negative response to sound (2.7%) had a sensitivity of 35.0 per cent and a positive predictive value for a nonreactive NST of 77.8 per cent. Results of sound-provoked fetal movement test and NST, performed within a week of delivery, in 434 women were compared with fetal outcome. The maternal perception of sound-provoked fetal movement test had better specificity (99.1% vs 96.9%), positive predictive value (55.6% vs 35.0%) for poor fetal outcome than the NST, although its sensitivity (50.0% vs 70.0%) and negative predictive value (98.8% vs 99.3%) were lower. Maternal perception of sound-provoked fetal movement test may suffice as an inexpensive and simple method of evaluating antepartum fetal well-being in risk situations. When the mother does not feel any sound provoked fetal movement, NST is then performed. This clinical application can be helpful in a primary health care setting where rapid assessment of fetal health at risk is required.

Rapid karyotyping in the second and third trimesters for fetuses at risk of chromosomal abnormalities at Chulalongkorn Hospital.

Transabdominal fetal blood sampling under ultrasonic guidance was performed in 20 fetuses at 18 to 34 weeks gestation. Pure fetal blood was obtained in all cases; 11 from the umbilical veins at the placental cord insertion, 7 from the fetal intrahepatic veins and 2 from the fetal hearts. Rapid karyotype was obtained within 7 days by fetal lymphocyte culture. Chromosomal abnormality was detected in 5 (25.0%) fetuses. Abnormal karyotype was found in 4 of 8 fetuses with structural malformations detected by antenatal ultrasound and in 1 of 5 fetuses of elderly mothers at advanced gestational ages. This suggested that in fetuses at risk of chromosomal abnormality, rapid karyotype should be obtained and fetal blood sampling is justified in the second or third trimester.

Intrauterine growth retardation: incidence, screening results, pregnancy outcome.

Intrauterine growth retardation is detrimental to the health of fetuses and neonates both immediately and in the long run. A risk scoring system to help screen for this complication has been developed as a result of this prospective study. With the incidence of intrauterine growth retardation at approximately 9 per cent in this study population, the final risk scoring system with its 6 variables and total score of 10 was found to be quite useful as a screening method because of its high sensitivity (91.18%) and high negative predictive value (98.14%). Screening by this risk scoring system should be helpful and prove practical among health personnel with varying levels of expertise and experience. Most gravidae had easy labour and delivered within 24 hours. Instrumental delivery rate was high with caesarean section rate of 17.6 per cent. Almost 70 per cent of the intrauterine growth retarded babies were symmetrical type and the perinatal mortality rate in this group was 42.3 which is approximately 4 times that in general population delivered at this hospital.