Medical Truth or Old Wives Tale?

Yesterday morning I had my first appointment with my high risk (perinatologist) doctor. This doctor will monitor the babies physical development and look more in depth at everything going on in my uterus. I will still see my normal OB (Dr. Volker) every few weeks, but in addition to Dr. Volker I will see this doctor every two weeks until I get close to delivering, than it will be every week. Anyway, during my ultrasound the technician was 90% sure that baby "b" is a boy. I am so excited! We really wanted at least one boy! Rob's only brother Scott and his wife Carrie just had their fourth child- a girl, so they now have 4 girls. There was some pressure from Grandpa Fred about having the Finlinson name carry on. So were thrilled that there will be a new Finlinson baby boy! I am only 13 weeks pregnant so it was still a little early to be 100% sure by looking at the baby. But 90% sure is enough for me to feel comfortable buying some baby clothes!

So what about baby "a"....well this baby is a little stubborn. He/she would not turn around so that we could take a look at the lower anatomy. I am determined that baby "a" is a girl. When they listened to the heart beats, baby "a" was at 182 bpm and baby "b" was at 150 bpm. Now legend has it that girl's have a faster heart beat and boys are usually a little slower! Based on this legend or myth, I am thinking that baby "a" is a girl. What do you think? I need your comments on this one. Is the faster heart beat something based on medical truth or is it an old wives tale? I won't get another shot at seeing baby "a" for another two weeks and I am looking for validation on my opinion! So please, tell me what you think!