both my boys were 140 to 150 and so is the girl I’m carrying. I asked my doc about this heart rate thing, with my last pregnancy. He said the only way it would come close to predicting gender, is if you listen to the hear rate every minute (take a minute by minute reading), for about 12 hours straight, the divided to get an ‘average’. That the 30 seconds it takes to get the heart rate is not an accurate way of telling gender.
Right now I am almost 16 weeks and I don’t know what the gender of my child is, this will be my second baby. My husband and I are going in on December 10th, but when I was 12 weeks the baby heart beat was over 150 and when I was in for my 8 week it was 167. My doctor is betting that we are having a girl.