Heart Rate as a Gender Predictor? Britt... you little stinker...

Scientific data to counter the theory as found in multiple studies, the latest being 2006.

Our baby had a heart rate of 170 at 8 weeks, 5 days...

As the old wives' tale has it, if your unborn baby's heart rate is higher, above 140 beats per minute, that means you're carrying a girl. A lower heart rate below 140 bpm means you're having a boy.

It's hard to resist such an easy test, and ever so tempting to over-analyze the pitter patter of that tiny heart. In early pregnancy, the reassuring sound of that heartbeat is just about the only thing we've got to show a baby's even there. 

But don't get your hopes up, or have your hopes dashed, based on your baby's heart rate, because it has absolutely nothing to do with what your baby has between its legs. This particular old wives' tale was found to be completely false by a medical study 20 years ago. Another medical study in 2006 confirms that fetal heart rate has nothing to do with the baby's sex.

Here is a cool chart that shows the weeks of Pregnancy/heart rate (bpm), with a blue box for a boy and a pink box for a girl studied over 500 births... looks like it's still a coin-flip at this point.