Please make every effort to be informed before you proceed with this.
from http://www.mothering.com/articles/pregnancy_birth/birth_p...
"Ultrasound waves are known to affect living tissues in at least two ways. First, the sonar beam heats the highlighted area by about 1°C (2°F). This is presumed to be insignificant, based on whole-body heating in pregnancy, which seems to be safe up to 2.5°C (5°F).21 The second effect is cavitation, where the small pockets of gas that exist within mammalian tissue vibrate and then collapse. In this situation "...temperatures of many thousands of degrees Celsius in the gas create a wide range of chemical products, some of which are potentially toxic."22 The significance of cavitation in human tissue is unknown.
A number of studies have suggested that these effects are of real concern in living tissues. The first study indicating problems analyzed cells grown in the lab. Cell abnormalities caused by exposure to ultrasound WERE SEEN TO PERSIST FOR SEVERAL GENERATIONS.23 [Are you pregnant with a girl? She'll have all the eggs she'll ever have before she's born, so this applies to your potential grandchildren.]
Another study showed that, in newborn rats (who are at a similar stage of brain development as humans at four to five months in utero), ultrasound can damage the myelin that covers nerves,24 indicating that the nervous system may be particularly susceptible to damage from this technology. In 1999, an animal study by Brennan and colleagues, reported in New Scientist,25 showed that exposing mice to dosages typical of obstetric ultrasound caused a 22 PERCENT REDUCTION IN THE RATE OF CELL DIVISION, AND A DOUBLING OF THE RATE OF CELL DEATH in the cells of the small intestine.
*****Studies on humans exposed to ultrasound have shown possible adverse effects, including premature ovulation,26 preterm labor or miscarriage,27, 28 low birthweight,29 poorer condition at birth,30, 31 dyslexia,32 delayed speech development,33 and less right-handedness,34, 35 a factor which in some circumstances can be a marker of damage to the developing brain. In addition, one Australian study showed that babies exposed to five or more ultrasounds were 30 percent more likely to develop intrauterine growth retardation (IUGR)--a condition that ultrasound is often used to detect.36*****
Two long-term randomized controlled trials, comparing exposed and unexposed children's development at eight to nine years of age, found no measurable effect from ultrasound.37, 38 However, as the authors note, intensities used today are many times higher than in 1979 to 1981. A later report of one of these trials39 indicated that scanning time was only three minutes. More studies are obviously needed in this area, particularly in Doppler ultrasound, where exposure levels are much higher, and in vaginal ultrasound, where there is less tissue shielding the baby from the transducer.
A further problem with studying ultrasound's effect is the huge range of output, or dose, possible from a single machine. Modern machines can give comparable ultrasound pictures using either a lower or a 5,000 times higher dose,40 and there are no standards to ensure that the lowest dose is used. Because of the complexity of machines, it is difficult to even quantify the dose given in each examination.41 In the US, as in Australia, training is voluntary (even for obstetricians), and the skill and experience of operators varies widely."