How we may be missing some harmful effects of ultrasound--a hypothesis

In spite of documented effects of ultrasound on living cells in vitro, we have not been able to consistently demonstrate adverse effect after in-utero fetal exposure. This may be because we have used traditional obstetricians' 'week' as the time frame of reference and/or because we have based most studies on the concept of 'biologically plausible' hypotheses. However, large and vulnerable transformations occur in-utero in very short time frames during organogenesis and our knowledge of the functionality of organs at various stages of development is still rudimentary. Using time frames in 'weeks of gestation' may cause large effects to appear small and insignificant. In first trimester fetal exposures, a time frame of '1 day' may be more appropriate. We may need to re-evaluate the safety of diagnostic ultrasound using much shorter in-utero time frames. This may either expose hidden adverse effects of ultrasound or give further reassurance of its safety.