$re = '/(gclid|utm_[a-z]+)=[-_A-z0-9+()%.]+&?/';
$str = '"http://wearychef.com/chicken-spaghetti-casserole/?utm_source=MadMimi&utm_medium=email&utm_content=7+Easy+Dinner+Recipes+Featuring+Chicken+Spaghetti+Casserole+(PLUS+A+Call+For+Feedback)&utm_campaign=20150620_m126272097_06202015+chicken+spaghetti+and+menu+126&utm_term=Chicken+Spaghetti+Casserole"';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php