Risks of Ultrasound Scanning

Beverley Beech

Midwifery Today E-News, volume 1, Issue 31, July 30, 1999.

Saari Kemppainen: 20 miscarriages after 16-20 weeks, none in the control group. Davies: 16 perinatal deaths compared with 4 perinatal deaths in the control group. Lorenz: Preterm labour was more than doubled in the ultrasound group -- 52% compared with 25% in the controls. Taskinen: A significant increased risk of spontaneous abortion amongst physiotherapists who use ultrasound for at least 20 hours a week and deep heat therapies for more than 5 hours a week.

Apart from the last two studies the others are random controlled trials. For more information and discussion about the risks of scanning see Ultrasound Unsound? which Jean Robinson and I wrote about the risks. Copies available from AIMS Publications, 2 Bacon Lane, Hayling Island, Hants, PO11 ODN. (#6.25 for orders outside the UK; #5.75 for orders within the UK).

I do not agree with the statement that "a lot of embryos have been exposed to ultrasound over the last 25 years with no documented ill effects." Lieberskind's research indicated changes in cell structure that persisted over 10 generations and although researchers attempted to rubbish the research it was repeated by other researchers, and now we have research from Ireland that also shows affected cells.

There is a widespread assumption that ultrasound is beneficial, yet there is no evidence that infant outcomes have been improved by routine ultrasound examinations. Researchers have enthusiastically focused on what ultrasound could find but have paid little or no attention to the potential adverse long-term effects. As a result, despite ultrasound being enthusiastically used over the last 30 years, there is no good research that addresses the anxieties that ultrasound may be responsible for dyslexia, learning difficulties and behavioural problems.

The Saari Kempaainen study revealed that 150 women were diagnosed as having placenta praevia; when they got to term only 4 women actually had it. In the control arm the women who were not exposed to ultrasound also had 4 women whose placenta praevias were discovered when they went into labour. Both sets of women had caesarean sections and there was no difference in outcomes. The researchers did not investigate the amount of stress a diagnosis of placenta praevia could have caused in the 146 misdiagnosed women. This research shows that early diagnosis of placenta praevia is irrelevant and a complete waste of time, yet doctors and midwives persist in telling women they have low lying placentas.

A study by Jahn revealed that out of 2,378 pregnancies, only 58 of 183 growth retarded babies were diagnosed before birth, and 45 fetuses were wrongly diagnosed as being growth retarded when they were not. Only 28 of the 72 severely growth-retarded babies were detected before birth. Furthermore, the diagnosed babies were more likely to be delivered by caesarean section (44.4%) compared with 17.4% for the babies who were not small for dates. If a baby actually had IUGR the section rate varied hugely according to whether it was diagnosed before birth (73.1% sectioned) or not (30.4%). Preterm delivery was 5 times more frequent in those whose IUGR was diagnosed before birth than those who were not.

The average diagnosed pregnancy was 2.3 weeks shorter than the undiagnosed one. The admission rate to intensive care was 3 times higher for the diagnosed babies. This important study provides further evidence that scans are not benefiting babies or those mothers who were subjected to caesarean sections.

References:

Davies JA et al. (1992, Nov). Randomised controlled trial of Doppler ultrasound screening of placental perfusion during pregnancy The Lancet, Vol.340: 1299-1303
Jahn A et al. (1998). Routine screening for intrauterine growth retardation in Germany: low sensitivity and questionable benefit for diagnosed cases. Acta Obstet Gynae Scand. 77: 643-689
Liebeskind DE et al. (1979a). Diagnostic ultrasound: effects on the DNA growth patterns of animal cells, Radiology, 131: 177-184
Lorenz RP et al. (1990, June). Randomised prospective trial comparing ultrasonography and pelvic examination for preterm labor surveillance. Am. J. Obstet. Gynecol: 1603-1610
Olsen O and Clausen JE. (1997, Nov). Routine ultrasound dating has not been shown to be more accurate than the calendar method. British Journal of Obstetrics and Gynaecology, Vol 104: 1221-1222
Saari-Kemppainen et al. (1990). Ultrasound screening and perinatal mortality: controlled trial of systematic one-stage screening in pregnancy, The Lancet, Vol 336: 387-391
Taskinen H et al. (1990). Effects of ultrasound, shortwaves, and physical exertion on pregnancy outcome in physiotherapists J. of Epidemiology and Community Health, 44: 196-201


Ultrasound? Unsound is also available from Midwifery Today at a cost of $12 plus $2.50 S&H in the United States, $3.00 S&H to Canada and Mexico, and $3.25 S&H (ground) to all other international addresses. Call 1-800-743-0974 to order. Mention code 940.


Reprinted from Midwifery Today E-News (Volume 1, Issue 31, July 30, 1999)

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