Cynthia Sigler's son Jayden weighed in at 13 pounds and 14 ounces. He was delivered on Thursday by cesarean section at the Tri-City Medical Center.
Doctors had a hunch that Jayden was going to be a big one, but they were thinking 9 pounds or maybe 11 pounds at the most.
Even the doctor, who has delivered some 20,000 babies, says this is the biggest one yet.
Jayden's birth weight is almost twice that of his sister, Jailyn, now 2½. She was 7 pounds, 2 ounces at birth.
Both mom and baby are doing just fine, though she jokes she'll probably have to exchange some of his newborn clothes.
The Associated Press contributed to this report.