I am 37 years old, 4 weeks pregnant, and have scheduled my first appointment with my OBGYN who will only see me at 6 weeks. I was told that my doctor will do a urine test and a transvaginal ultrasound at this first appointment to confirm the pregnancy and take a measurement. I have heard from a very trustworthy source to avoid this ultrasound because of the dangers of miscarriage, and to wait until the end of the first trimester to have any ultrasound.
I am quite healthy but because of my age I'm feeling very careful and obviously want to minimize any risks of miscarriage. What are the dangers of an ultrasound on the fetus? Do you recommend to your patients that they minimize if possible the amount of ultrasounds they have throughout a pregnancy?
I do recommend minimizing ultrasounds during pregnancy. That said, if there is a major question about when the child was conceived, a first trimester ultrasound is the gold standard for dating.
Once a woman is about 7-8 weeks along, that can be done abdominally, and as long as everything seems okay before that, that is soon enough to date the pregnancy. For planned out-of-hospital birth, I also recommend an ultrasound about 20 weeks to verify that the anatomy is all as it should be, because we would rather not be out of the hospital if something is going on that can be corrected if specialized help is immediately available.
On the other hand, for a woman with good dates who is planning a hospital birth, it is totally up to the woman whether or not she has any ultrasound at all unless there is a clear medical need to find out what is going on. Just my opinion.