Old Mexican beliefs


So today Is the super snow full moon and in my Mexican family I have been told that when you are pregnant you should put a metal safety pin on your shirt and wear it on top of your stomach through the full moon to avoid the baby being affected in any way. I’ve always been skeptical about this ritual. Just want to hear what y’all think about it? Or if y’all think a full moon has some type of positive/negative on the unborn baby?