any truth to the heart rate?

Amy Jo • 29, married to the love of my life, mommy to an amazing baby boy 8•11•15, now expecting #2 in April ❤️
Just wondering if there's any truth to if the heart rate Therory? I've heard that girls heart rates are faster than boys. My sons was always in the low 160's and then went down the further along I got. This one has been 157-159. Has anyone had boys with faster heart rates or girls with lower heart rates?