Girls, hi! Mom always told me that you shouldn't lift your hands up du…

Girls, hi! Mom always told me that you shouldn't lift your hands up during pregnancy. They say it will cause umbilical cord compression. And I remember this since I was 14 years old, somewhere ? And now I read tons of posts about someone having one cord wrap, someone having two ?? These facts somehow relate or is lifting your hands up just an exaggeration? What causes these cord wraps in such cases anyway?