I don't know... If you'd asked me weeks ago, I would have said yes, I bought into it. But I don't know anymore...
I've had three confirmed genders with my pregnancies, (this one is currently unknown, but suspected).
With Greg, his heartrate was always around 133. Pregnancy #5, which DNA testing showed was a boy, also had a heartrate of 133-135. Devon was consistently 160, with a 155, or a 165 thrown in here and there. Definately a girl there.
This one... I don't know... Started out at around 150. Went up to 170. Went down to 160. Went down to 155. Stayed 155 for a while. After my surgery on the 13th for my Sharodkur, it was 144. A subsequent scan the next day was 137... So what the hell?? It is NOT consistent whatsoever.
AND... I am pretty sure there was a dinkle on one of my last, post op, scans. The tech said it would be illegal to tell me yet as it could be swollen labia. So we are leaning towards boy now, with a heartrate that has been ALL over the place!