Count records returned from a SQL procedure in PHP

Good afternoon,

I'm a beginner in PHP and I'm running the code below, the records are returning correctly, however I can not count the number of records returned and print on the screen. It prints the -1 amount, before I was doing a simple select instead of using the procedure and was counting normally.

$sql = "Exec [rh].[SP_Gas_Vagas_Inicio] '$usuario','$perfil';";
$result = odbc_exec($connect , $sql);
$qtd = odbc_num_rows($result);

Can anyone help me?