In 1980 the Federal Republic of Germany initiated a two-stage ultrasonographic screening program as an integral part of antepartum care offered to every pregnant woman in the country. Similar policies have been either adopted or recommended in several other European nations. Consideration was then given in the United States as to whether routine ultrasound sccaning in pregnancy should be feasible.
In 1984 a consensus conference convened by the National Institutes of Health (NIH) in the United States addressed the issue of performing ultrasonography on all pregnant women. The panel listed 28 clinical situations in which the use of ultrasonography was potentially beneficial, but it did not find evidence that routine ultrasonography decreased perinatal morbidity or mortality. The rate of detection of twin gestations and congenital malformations was increased with ultrasonography, and pregnancy could be dated more accurately, but outcome was not improved. The panel therefore recommended that ultrasonographic examinations should be performed during pregnancy only for specific medical indications and that "randomized, controlled clinical trials of routine ultrasound screening during pregnancy should be conducted in the United States."
The Routine Antenatal Diagnostic Imaging with Ultrasound Study (RADIUS) appeared in the American Journal of Obstetrics and Gynecology in 1993 and was one of the most frequently quoted article on the topic of Routine ultrasound screening in pregnancy. It was a large and well-designed study which found that routine ultrasound scanning of a group of low-risk women provided no benefits in reducing neonatal deaths or reducing the incidence of moderate or severe illness. screening.
The study showed that:
" Major congenital malformations occurred in 2.3% of the 15,281 fetuses and infants in this study. Antenatal ultrasonography detected 35% of the anomalous fetuses in the screened group versus only 11% in the control population (relative detection rate 3.1; 95% confidence interval 2.0 to 5.1). Ultrasonography screening did not, however, significantly influence the management or outcome of pregnancies complicated by congenital malformations. Specifically, only 9 abortions were performed for anomalies among 7685 fetuses in the screened group whereas 4 pregnancies were terminated for fetal anomalies detected among 7596 control subjects. Ultrasonography screening also had no significant impact on survival rates among infants with potentially treatable, life-threatening anomalies despite the opportunity to take precautionary measures such as delivery in a tertiary center ".
It detected more problems than were found in a similar group of unscanned women, but the information often came too late to be useful. And it is not inexpensive. About half of the $1 billion spent on ultrasound for pregnancy each year goes for routine
The American College of Obstetricians and Gynecologists and the American Academy of Family Physicians advised against routine screening unless there is medical justification
Read also an important Editorial by Richard Berkowitz in the September 16 issue of the New England Journal of Medicine addressing the same subject.
In another large database in Europe, the EuroFetus Study which was first reported at the New York Academy of Sciences conference in 1997 and later in the American Journal of Obstetrics and Gynecology in 1999, it was found that ultrasound screening in Europe was far more effective at identifying problems than screens done in the United States. Also, the screening costs much less in Europe.
In the study, with 60 European hospitals participating, ultrasound screening performed on healthy pregnant women between 18 and 22 weeks of gestation detected 56% of 4,615 congenital structural anomalies, including 73% of all major abnormalities. 210 of 378 chromosomal anomalies were detected before birth. The findings strengthen the case for ultrasound screening and raise questions about the way it is done in the U.S. The study showed that European doctors found fetal disorders at strikingly higher rates than their U.S. counterparts. Looking back at 3,685 infants born with birth defects, the study found that defects in 61.4% of the infants were detected by ultrasound screening--twice the rate found in the U.S. study. And 56% of those defects were detected within 24 weeks of pregnancy, when it is still legal for an American woman to have an abortion. (It's rare that anything can be done to correct birth defects.) In contrast, in the RADIUS study, just 17% of the defects identified were found by the 24th week.
In the Eurofetus database, all sonograms were done in hospitals--usually by certified technicians. In the U.S., they're often done in doctors' offices. Even the RADIUS study, though it found a smalll U.S. detection rate overall, showed that hospitals and high-quality laboratories detected three times as many abnormalities as doctors' offices did.
Another point relating to the lack of cost-effectiveness as found in the U.S. study is that the average cost of a routine sonogram in Europe is about $50, vs. $200 in the United States.
In a paper "Routine Ultrasound Screening In Low-Risk Pregnancies: Imperatives for Further Study" which appeared in the April issue of Obstetrics and Gynecology, Jeffrey Ecker and Fredric D. Frigoletto from the Massachusetts General Hospital at Harvard Medical School in Boston, concluded that the medical benefit of ultrasound screening in low-risk pregnancies remains questionable and call for further studies to determine for which population(s) and for what specific conditions ultrasound is most beneficial.
Salvatore Levi in his paper "Routine ultrasound screening of congenital anomalies. An overview of the European experience" which appeared in the Annual of the New York Academy of Sciences in 1998 pointed out that:
" Results from ultrasound in low-risk pregnant women are significant when routine screening is performed on a large population because the anomalies are rare. Professionals expect from routine ultrasound objective information that cannot usually be obtained by clinical procedures. Parents seek reassurance about the absence of fetal congenital anomalies and overall fetal health. Therefore, Europeans view routine ultrasound as a part of obstetrical care, capable of filling important gaps by delivering much key information for improving obstetrical practice. Fetal anomalies screening (FAS) requires higher education and qualifications than obstetrical ultrasound. The health insurance systems support ultrasound screening and allow its spread in most European countries; approximately 98% of pregnant women are examined by ultrasound and, frequently, two to three times (usually once per trimester). Detection rate of congenital anomalies is about 28% in geographical areas (private practice and hospitals), 60 to 80% in Ob/Gyn's ultrasound labs. Routine ultrasound screening policy has not proved to result in an immoderate use of ultrasound; on the contrary, chaotic use of routine ultrasound can lead to an unproductive and excessive number of scans. New trends in FAS, such as the early detection of fetal defects and chromosomal anomalies, bring more arguments for routine screening. Effectiveness should increase by enhancing education and training and the systematic referral for FAS to accredited laboratories ".
Read also the book: Ultrasound Screening for Fetal Anomalies: Is It Worth It? Screening Revisited after the Eurofetus Data by:
Salvator Levi (Université Libre de Bruxelles, Belgium) and Frank A. Chervenak (The New York Hospital-Cornell Medical Center, New York), Eds.
( Editorial Review of this book from Book News, Inc. :
The debate centers around whether or not the results are worth the effort and expense of the procedure, rather than worth any negative effect the procedure might have on the fetus. A 1993 US study showed only a 35% detection rate and concluded that screening was not effective enough, but a 1993 European study showed a 61% rate, which reversed many scientists' minds. The 25 papers here, from a June 1997 meeting in New York City, cover the relevance of fetal anomalies to clinical practice, whether prenatal diagnosis affects perinatal outcome, critical analysis of methods and results, lessons from the Eurofetus database, the need for policies concerning congenital anomaly screening, the consequences of detecting or missing anomalies, and challenges in ultrasound screening. Five additional poster papers discuss a variety of issues. Book News, Inc.«, Portland, Oregon.)
The issue of Routine Ultrasound Screening in pregnancy remains controversial. Its is likely the arguments and conclusion will be different for a different population. More work are forthcoming.
Back to History of Ultrasound in Obstetrics and Gynecology.