Alliance for the Improvement of Maternity Services (AIMS)

Return to Home Page

ULTRASOUND IN OBSTETRICS: A QUESTION OF SAFETY

In December of 2000, decades after ultrasound was approved by the FDA for use in obstetric that Agency acknowledges that no one knows the delayed, long term effects of diagnostic levels of ultrasound on human development.

Millions of women and their unborn children are being exposed to diagnostic ultrasound during pregnancy and childbirth without the women being advised prior to exposure that there has been no well-controlled scientific investigation carried out to study the delayed, long-term effects of ultrasound on human development. Ova, embryos and fetuses are often exposed to prolonged sonography because the physician or technician lacks sufficient expertise to evaluate what he or she is seeing.

The FDA has yielded to pressure from industry and organized medicine to relinquish control over the amount of sonic energy that can be emitted by the new ultrasound devices used in obstetrics. The new ultrasound machines will beep at certain levels of energy output but essentially there will be little or no limit on the energy the health care provider may choose to use.

Despite the fact that the FDA's Center for Devices and Radiologic Health acknowledged the potential risks of ultrasound used in obstetrics in its 1982 publication "An Overview of Ultrasound", edited by Stewart and Stratmeyer, there is no evidence that health care providers are obtaining women's truly informed consent to the use of ultrasound in pregnancy.

There are no state or federal regulations which require periodic calibration of ultrasound devices used in obstetric care. Nor are there any regulations that require a record to be kept of basic information such as:

• The indication for the procedure

• The written consent of the patient

• The name of the manufacturer and the model number of the ultrasound equipment used

• The type of ultrasound employed

• The proposed intensity, as well as the actual intensity of exposure

• The proposed and actual length of exposure

• Maternal height, weight, and temperature

• Identification of the hospital or the office where the procedure is carried out

• Identification and qualification of sonographer

• Date of exposure

Numerous studies have been carried out to evaluate the effectiveness of routine diagnostic ultrasound. None has shown the routine use of diagnostic ultrasound to improve maternal and infant outcome over that achieved when diagnostic ultrasound was used only when medically indicated.

Are women overly concerned regarding the safety of ultrasound used in obstetrics? A letter published in the July 1988 issue of the British Journal of Obstetrics and Gynaecology, from Dr. Robert Bases, Chief of the Radiobiology Section, Albert Einstein College of Medicine, calls attention to the 1984 review by Stewart and Moore of over 700 publications since 1950 which demonstrate the present chaos in delineating and controlling exposure conditions and the bewildering range of ultrasound bioeffects. Bases states in his letter:

"The increased frequency of sister chromatid exchanges induced by pulsed ultrasound in human lymphocytes, first described by Liebeskind et al (1979), has been amply confirmed in reports from four independent laboratories involving studies of pulsed as well as continuous wave ultrasound (Haupt et al 1981; Ehlinger et al 1981; Ozawa et al 1984; Stella et al 1984). Recently further evidence that sister chromatid exchanges in human lymphocytes are induced by high-intensity pulsed ultrasound has been presented by Barnett et al (1988), who are now able to confirm the previous results."

"Free radical production in amniotic fluid and blood plasma by medical ultrasound, probably following gaseous cavitation, has been detected by Crum et al (1987). This provides a likely mechanism for the origin of the DNA damage. Because of these confirmations and a report by Ellisman et al (1987) that diagnostic levels of ultrasound may disrupt myelination in neonatal rats, the need for regulation, guidance, and properly controlled clinical studies is clear."

The implications of premature ovulation after ovarian ultrasonography, reported by Testart et al, are disturbing. If ultrasound can affect the adult ovary, what then is the effect of ultrasound on the ova of the female fetus?

 

Even if we begin today to carry out a well-controlled investigation into the delayed long-term effects of obstetric ultrasound it will be 20 or 30 years before we will know whether ultrasound will be the DES of the next generation.

Even where there is a medical indication of need the woman has a right to be informed, and her health care provider has a legal obligation to advise her, of the potential risks and relevant areas of uncertainty regarding the latent effects of ultrasound. "Weasel wording", which implies that proper research has been carried out and no risks found, rather than a clear statement regarding potential risks is still the norm in most health care facilities.

The consent form would be invaluable in carrying out an investigation as to the delayed, long term effects of ultrasound, not just in the case of obstetrics but for all uses of ultrasound. The consent form offers several benefits.

1. It would help to insure that women will be advised of the risks and areas of uncertainty before granting consent to diagnostic ultrasound.

2. It would create a data base for a long term follow up of exposed offspring.

3. It would help to protect the provider from malpractice suits if time proves ultrasound to be harmful to human development.

4. It would shift or share the potential liability by identifying the manufacturer of the device.

American women should not assume that health care providers always know what is best for them. Information needed by the woman, if her consent is to be truly informed, must include the fact that no properly controlled scientific investigation has been carried out to evaluate the delayed long-term effects of ultrasound.

All of us, whether we are health care providers, scientists or consumers, hope that time will prove ultrasound to be safe. However, until well-controlled research has established ultrasound to be without harm women must be informed of the areas of uncertainty concerning themselves and their babies.

©2000 DORIS B. HAIRE