Routine Prenatal Ultrasound Screening Research Articles

Routine prenatal ultrasound screening for fetal abnormalities: 22 years' experience.

We describe the results of routine obstetric ultrasound examination over a period of 22 years (1970-91) at the Institut Universitari Dexeus, Barcelona, Spain. A total of 1006 malformed fetuses or neonates were identified at abortion or delivery. The prevalence of fetal abnormalities was 3.03%. Fetal anomalies were diagnosed antenatally in 788 (78.33%) cases. Early prenatal diagnosis (before 22 weeks of gestation) was made in 598 (59.44%) cases. The detection of malformed fetuses increased from 19.75% in the first phase of the study (1970-74) to 96.33% in the last phase (1990-91). The specificity of the method was over 99% throughout the study period. The most frequently diagnosed anomalies were urinary tract anomalies (22.86% of cases), followed by head and neck anomalies (18.68%), musculoskeletal anomalies (8.64%), heart anomalies (7.35%) and gastrointestinal anomalies (7.35%). The earliest diagnosed malformations were those of the thoracoabdominal wall (81.08%), followed by defects of the urinary tract (70.86%) and of the diaphragm (70.83%).

Evaluation of routine prenatal ultrasound examination in detecting fetal chromosomal abnormalities in a low risk population

Prenatal diagnosis performed by fetal ultrasound scan is now a routine part of antenatal care in many countries. We have used our registry of congenital malformations to determine how many fetal anomalies and consequently how many chromosomal abnormalities are detected by this procedure. In our region, evaluation of prenatal diagnosis of chromosomal abnormalities in women of 38 years and younger (chromosomal prenatal diagnosis is offered to women > or = 38 years) with no personal or familial history of chromosomal anomaly was performed in 119,099 consecutive pregnancies of known outcome from 1980 to 1987. At least one ultrasonographic examination seeking congenital malformations was performed in more than 95% of the pregnant women studied. The total number of chromosomal anomalies during the study period was 199, 123 of these being Down syndrome. Only 41 (34.5%) of the 119 fetuses with chromosomal abnormalities and congenital malformation examined had been found to have a malformation at ultrasound examination. This low sensitivity was different for the diverse chromosomal abnormalities. Only 10 out of the 54 fetuses with Down syndrome and malformations (18.5%) were detected and only 3 out of 24 (12.5%) atrioventricular canal defects in those trisomic 21 patients were detected. Only 5 out of 11 (45.4%) fetuses with trisomy 13, 13 out of 26 (50.0%) fetuses with trisomy 18, 7 out of 12 patients with monosomy X (58.3%) and 6 out of 27 (22.2%) fetuses with other chromosomal abnormalities were diagnosed. Moreover, the time of detection of these anomalies was early enough to allow amniocentesis and termination of pregnancy in the case of a chromosomal abnormality in only 15 out of these 41 patients, including 7 cases of cystic hygroma in fetuses with monosomy X. This low sensitivity is not the result of the quality of the ultrasound equipment. It may be explained by the inadequate qualification of some operators and by the insufficient duration of the routine examination. In conclusion, our study has shown that the sensitivity of the detection of chromosomal abnormalities by routine prenatal ultrasound screening is low. Other screening methods are needed.

IS ROUTINE ULTRASOUND WORTHWHILE DURING PREGNANCY

Routine prenatal ultrasound screening can detect a variety of abnormalities, but it is unclear whether this information translates into better perinatal outcomes. This multicenter trial randomized over 15,000 women with low-risk pregnancies to have two routine ultrasound …