How can I remove unwated parts of a string in a pattern match?

Select or download this

weight gain

Select or download this

4;T;X;15;O20;O26.0;O26.0;O260;Excessive weight gain in pregnancy;242;U
+NDEF;UNDEF;2-067;1-089
4;T;X;15;O20;O26.1;O26.1;O261;Low weight gain in pregnancy;242;UNDEF;U
+NDEF;2-067;1-089

Select or download this

if($big_string=~/$small_string/) {print "Found match\n";}

Select or download this

Excessive weight gain in pregnancy
Low weight gain in pregnancy

Select Code to Download