Risk Management Articles

"Limited" Fetal Ultrasound Exam:
Risks May Exceed Benefits
by Michael Lem M.D.,
Board Certified in Obstetrics & Gynecology

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Your patient, Mary Smith, and her husband are expecting their third child.Mary is a healthy, 30-year old mother of two; both children were delivered vaginally at full term. Mid-way through her second trimester, Mary and her husband are curious about the gender of their future child. Although Mary appears to have no clinical indications for an ultrasound examination, they have asked you to determine the sex of the fetus. If you comply, utilizing your own staff and equipment, what are the risks?

Expectant parents want assurance that they will have a healthy child, and clinicians are eager to respond. But in our litigious society, performing a "limited" ultrasound examination must be approached with great care. CAP/MPT continues to receive claims for missed diagnoses of fetal anomalies, overlooked or misidentified in the course of "limited" exams. Will the "limited" exam supply the evidence that converts your otherwise defensible liability claim into a loser? Routine screening ultrasounds have not been shown to decrease perinatal morbidity or mortality.1 Although ultrasonography has revolutionized the care of high-risk pregnancies, routine examinations have not improved outcomes for low-risk patients. Also, parental curiosity about gender does not qualify as a clinical indication for ultrasonography during pregnancy.2 Nevertheless, expectant parents know that their baby's sex can be determined with an ultrasound. Not surprisingly, expectant parents ask their obstetrician for an ultrasound exam, regardless of the health of the mother or fetus.

In addition to satisfying your patient's curiosity, you know that second trimester ultrasound can detect fetal anomalies, provide for early diagnosis of multiple gestation, and perhaps provide other benefits. Add in the prospect of increasing office revenues and it is not difficult to rationalize the acquisition of ultrasound capability. But, before you leap headlong into this technology, you may wish to consider the following issues.

Is it prudent to offer a "limited" ultrasound procedure that falls short of a thorough examination of fetal anatomy? Merely offering the examination implies a degree of professional skill. Are you and your staff qualified to proceed beyond the "limited" exam, if necessary? The quality of ultrasound examination appears to depend more on the experience of the operator than on the technical capabilities of the equipment.3 While a simple determination of fetal gender may not require exceptional skill, the operator will be asked to exceed the limits of the exam. Few expectant parents will be content with merely learning the sex of the fetus: "If you notice any problems during the ultrasound, you'll certainly tell us, won't you?" "Everything looks O.K., right?"

Without a frank discussion, and use of a customized informed consent document, your "limited exam" may suddenly expand, both in scope and in risk. Before you start the exam, does your patient understand that additional testing and expense may be necessary if you detect a condition that requires follow-up? If you complete the limited exam, pronounce the fetal gender and turn off the machine, have you not reassured the parents, nonetheless?

Will you perform the ultrasound examination, or delegate this function to a technician? How much time away from your practice can you devote to training in ultrasonography? What is an appropriate charge for a "limited" exam? Have you considered the options of videotape interpretation by a trained ultrasonographer, or real-time fetal telemedicine?

To avoid sending the implied message that "everything's fine," more planning and preparation may be required than is commensurate with the purpose of the limited exam, or the revenue it may produce.


1 Ewigman BG, Crane JP, Frigoletto FD, et al: Effect of prenatal ultrasound screening on perinatal outcome. N Eng) J Med 329:821-827, 1993.
2 U.S.Department of Health and Human Services: Diagnostic Ultrasound imaging in pregnancy. National Institutes of Health publication No. 84-667. Bethesda, MD, National Institutes of Health, 1984; American College of Obstetricians and Gynecologists: Ultrasonography in pregnancy. ACOG Technical Bulletin 187. Washington DC, ACOG, 1993.
3 Bemaschek G, Stuempflen I, Deutinger J, The influence of the experience of the investigator on the rate of sonographic diagnosis of fetal malformations in Vienna. Prenat Diagn, 16:807-811 1996.

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