The element variable {ce_first} is parsed inside every element and will be true (1) or false (empty) in a conditional to indicate if it is the first element for this entry.
Simplified case example:
{exp:channel:entries channel="your_channel" limit="10"} {custom_field} {heading} {value} <p>{if ce_first}This entry has <strong>{ce_count}</strong> elements.{/if}</p> {/heading} {/custom_field} {/exp:channel:entries}