The text plays on the acronyms 'IRA' which typically stands for the Individual Retirement Account, and the words 'Ignore', 'Retry', 'Abort' which are options that might appear in a computer dialog box. It uses these terms in a different context to suggest a humorous and inappropriate set of options in response to a girlfriend's pregnancy.
Girlfriend pregnant : ( I ) gnore ( R ) etry ( A ) bort ?