Your eligibility for Advance Parole, which allows you to travel outside of the US while waiting for your residency/adjustment of status application to be approved, all depends upon your immigration status BEFORE you submitted your adjustment application. If you were out of status and had accumulated more than 180 days of “unlawful presence,” you should not travel until after your residency application is approved, because if you do leave the US, you could be prevented from returning for 3 years or longer.
This area of US immigration law is very complicated and, considering what is at stake, you should be sure to speak to an attorney before applying for Advance Parole or traveling outside of the US.
Edward Weiner
Attorney at Law
http://www.immigration-aux-usa.com/