The doctor gave me the results of the first ultrasound with my first child. He said she had a possible heart defect and possibly downs syndrome because she never opened her fists during the ultrasound. I prayed and believed G-d for a healthy child, and she was born healthy and strong willed (probably why she keeps her fists balled).
My 7th child had a tiny, red, half-circle birthmark on each palm, because he kept his hands clenched so tightly before birth. The marks have faded now - he's 2-1/2 - but he's still a hard-charging, sock-'em-in-the-jaw kind of boy!