Читать книгу Informed Choices in Motherhood - Fiona Lee - Страница 26

The authors of a 2010 Cochrane review on fetal ultrasounds have stated this:

“Subjecting a large group of low-risk patients to a screening test with a relatively high false positive rate is likely to cause anxiety and lead to inappropriate intervention and subsequent risk of iatrogenic morbidity and mortality” (Alfirevic, Stampalija and Gyte, 2010).²⁵

In their article ‘Routine ultrasound in late pregnancy (after 24 weeks’ gestation)’, these authors found that “there is no evidence that routine ultrasound in late pregnancy improves perinatal outcome. Its use may increase the rate of caesarean section, and hence the risk of iatrogenic morbidity” (Bricker et al. 2008).²⁶

Like many other pregnancy and birthing interventions, we have been conditioned to think that what we are told to do must be the right thing to do. There is plenty of research to suggest that ultrasounds are not perfect and are certainly not recommended for routine use in low-risk pregnancies.

A Cochrane review on ultrasounds in 2015 also found the following:

"No clear benefit in terms of a substantive outcome measure like perinatal mortality can yet be discerned to result from the routine use of ultrasound" ²⁷ (Alfirevic et al. 2015).

There is evidence which suggests that ultrasounds can cause higher than safe levels of heat. The sonar beam can cause heating in the tissues being scanned. Doppler ultrasound which uses continuous rather than pulsed waves, has been found to cause significant heating, (especially in the baby's developing brain.)²⁸ During normal pregnancy increases in whole-body temperature up to 2.5 degrees C (36.5F) are considered safe. Heating in late-pregnancy fetal tissues exposed to normal pulsed and continuous Doppler ultrasound may be 1.4 - 5.8 degrees C (significantly higher than what is considered to be 'safe' levels.)

Both animal and human studies have shown that elevated temperature can cause abnormal development and even birth defects.

A Cochrane Review of routine ultrasound in late pregnancy concluded the following:

“There is no evidence that routine ultrasound in late pregnancy improves perinatal outcome. Its use may increase the rate of caesarean section, and hence the risk of iatrogenic morbidity. As a result of this review, it is not clear what aspects of late pregnancy ultrasound may be valuable in centres where it is undertaken” (Bricker et al. 2008).²⁹

One of the other issues with studies observing the effects of prenatal ultrasounds is that the scanning intensities today are up to 6-8 times higher than they were in the 1990s, when all of the large population-based studies assessing ultrasound safety were done.

Even the FDA (U.S. Food & Drug Administration) warns against the routine and medical unnecessary use of fetal ultrasounds. In a statement on their website, they warn that the long-term effects of heating and cavitation are unknown and that ultrasound scans should be done ‘only when there is a medical need, based on a prescription’.³⁰

A 2002 review of the safety of ultrasound in the prestigious journal of Epidemiology concluded:

“Until long-term effects can be evaluated across generations, caution should be exercised when using this modality during pregnancy.” ³¹