There have been three studies* so far that show a significantly higher rate of left-handedness in children exposed to sonograms during pregnancy. The question this raises is do/can sonogram energy damage, or at least change, the neurological development of a fetus.

* K.A. Salvesen, L.J. Vatten, S.H. Eik-Nes, K. Hugdahl, L.S. Bakketeig, “Routine ultrasonography in utero and subsequent handedness and neurological development,” British Medical Journal, Vol. 307, 1993, 159-64. H. Kieler, O. Axelsson, B. Haglund, S. Nilsson, K.A. Salvesen, “Routine ultrasound screening in pregnancy and children’s subsequent handedness.” Early Human Development, Vol. 50, 1998, 233-45.