UNDATED (AP) Separated Bismarck twins Abygail and Madysen Fitterer are five months old today.

The twins remain in serious condition at the Mayo Clinic in Rochester, Minnesota, after undergoing successful separation surgery last week.

The girls are the daughters of Stacy and Suzy Fitterer.

They were born joined at the chest and shared their front chest wall. Their livers also were joined and they shared part of an intestine.

Doctors say the girls are making gradual improvement.

The twins and their family have been at the Mayo Clinic since October. The girls are expected to be in intensive care for a few more weeks.

(Copyright 2007 by The Associated Press. All Rights Reserved.) APNP 01-08-07 0805CST | save this article / add to your favorites list