Updated

Two twin sisters are seeing double — or make that quadruple — after delivering two sets of twin boys Tuesday.

Twenty-one-year-olds Ashlee Spinks (search) of Indianapolis and Andrea Springer (search) of Conyers, Ga., delivered their boys by scheduled Caesarean sections Tuesday about an hour apart at Northside Hospital.

The women were six months pregnant when they found out they were both going to have twin boys due on the same date — Jan. 1, 2005.

Spinks came to Georgia several weeks ago to share the pregnancy with her sister, and Spinks' husband, Bert Means, flew into town Monday to join the birthing party.

The two couples said twins run in the families of all four parents, and that they did not use fertility drugs to conceive the babies.

Dr. Larry Matsumoto (search), a physician who specializes in high-risk pregnancies, said the chances of twin sisters being pregnant with twin boys due on the same date are probably one in a million.