Based on the high rate of false diagnoses in addition to the risk of ultrasound itself (especially when you have already had several) I, personally, would decline. If you are planning a home birth, there are very few things that you have to worry about that would need immediate medical attention. If you are birthing in a hospital, then I assume that would bring a measure of security that would cause you to worry even less. I have seen too many friends/family stress and worry about false diagnoses of heart or kidney defects, supposed "complete" placenta previa, etc - only to have a perfectly normal delivery and a totally healthy babe. We are declining any further ultrasounds during this pregnancy and will do so with future children, barring trauma like a car accident or excessive bleeding or something equally terrible.
I have a TON of research compiled on ultrasound, some of which are statistics on false diagnoses. If you'd be interested in seeing it, I'd be happy to email you the word document. Just pm me!
ETA: ultrasound is NOT non-invasive. During an ultrasound, baby is exposed to non-ionized radiation, heat, and excessively loud noise. That is why you hear so often of babies "hiding" from ultrasounds - they are trying to escape the pain! Ultrasound on a baby can cause cavitation, sinistrality, IUGR, and preterm labor, among MANY other things. The same ultrasound used on babies is used to dissolve kidney stones and the same exposure to a man's testicles can sterilize him for six months or more. What is that power doing to your baby? Not worth the risk IMO.
Last edited by KelseyH; 12-05-2012 at 08:08 PM.