C.W.
Too funny, because I always was interested in that too. My daughter's first heart rate was in the 150s and my Son's was around 110. When I asked the PA with my son, she just kind of smiled and said she wouldn't put money on it but sounded like a boy to her. I always heard girls 140s and above and boys 110-130s. But I know my nephew was in the 150s, so it doesn't always work.