Background:
I am 40, pregnant, and due May 20, 2006.  My OB suggests that I start
BPP's (biophysical profiles) that involve a sonogram weekly starting
at week 32.  I think this is a lot.  I already had quite a few
ultrasounds/sonograms.  I had 3 transvaginal sonograms after
concieving at the fertility clinic (I used iui insemination.)  I had
one transvaginal ultrasound exam at my first OB visit, I have had 2
ultrasounds at my maternal-fetal specialist at 18, and 25 weeks, and I
am scheduled for another at 32 weeks.  The one at 25 weeks was an
extra because my OB thought my belly measured a bit big, but on my
last visit I had another OB in the office that said I measured OK.  So
far all of my tests and ultrasounds have shown a healthy, but bigger
than average baby.  I skipped doing an amnio since my first trimester
screening and all the other tests showed good results.  I am concerned
with the number of ultrasounds I have had and possible effects on the
fetus.

Now for the question(s):
How common is it for OB's to recommend a biophysical profile EVERY
week, starting at 32 weeks? (considering my being 40 makes me high
risk, but so far all tests are good)  How often are biophysical
profiles usually done for my situation?

(I have done my own research about unknowns and possible risks of
sonograms/ultrasounds.  That is not really what I am looking for.  I
thought once a week sounded like a lot, and I would like information
on current practices to go along with what I know about the risks to
help me make a decision, and maybe tell the OB I only want to do one
every 2 weeks, or at certain specific weeks.)