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.