Are Ultrasounds Safe During Pregnancy?

If you’ve had an ultrasound during pregnancy you may remember that your baby kept turning away from the transducer (probe), and with persistence the technician continued to get a good view. Why do you think the baby was turning away?

What is an ultrasound?

Ultrasounds take a photo of your baby by bouncing high-frequency sound waves off it and translating the echo returns into a picture. The sound vibrations range anywhere from 20,000 to millions of vibrations per second. It’s still unclear what the long term side effects of the sound vibrations are, we do however know that in the short term cells behave abnormally after just one diagnostic ultrasound exposure. Unborn babies, just like us, are made up of cells.

In 2006 a prominent study was done on pregnant mice. (1) The study suggested that ultrasound exposure in the womb can cause brain abnormalities in the developing fetus. 

Researchers from Yale University School of Medicine report that a small, but significant, number of nerve cells in fetal mouse brains did not migrate to the correct location after being exposed to prolonged ultrasound waves. This process of cell migration, known as neuronal migration, is essential for proper brain development.

How Many Should You Have Done During Pregnancy?

The average number of ultrasounds a doctor orders during a normal pregnancy are 6-8. One is simply to get an “exact” due date, although you already know the first day of your last period. Another is just to get a position for the baby, although trained professionals should be able to feel from the outside where the baby is positioned. The average cost per ultrasound is $350, could this be an incentive?

The long-term effects of repeated ultrasound exposures on the human fetus are not known. "In light of all that remains unknown, having a prenatal ultrasound for non-medical reasons is not a good idea," the FDA said. It is up to you as the gatekeeper for your baby what is medically necessary and what is not.

In my professional opinion 3 should be the standard, or maximum amount for a normal pregnancy. One in the beginning to confirm status and connect the parent to the experience (this can also be done by listening to hearts tones only with a doppler), one at the genetic screening (if you are participating in Genetic Screening), and one late in the 3rd trimester to confirm there is no severe placenta previa (placenta blocking the birth canal).

Apart from the unknown side effects of ultrasounds on the fetus, these procedures can be dangerous when information is misinterpreted by care providers. For example being told you have a “big baby”. This is a common statement made to many pregnant people that can lead them to feel cornered into consenting to inductions or c-sections. Assessing accurate size and weight of a baby in an ultrasound has a 70% margin of error. Always gather a second opinion before consenting to extreme medical procedures like induction, vacuum extractions or caesarean section, and know that 8lbs is not a “big baby”.

With love and info,

Eyla

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References:

1. https://www.webmd.com/baby/news/20060807/ultrasound-affects-fetal-brain-in-mice#1

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1971756/

https://www.fda.gov/radiation-emitting-products/medical-imaging/ultrasound-imaging