Congrats to Josefina and Greg Walker of Stockton, who on Monday became the parents of rare identical Leap Year twins.

The twins - named Sofia and Isabella - were born at UC Davis Medical Center, according to a press release from the hospital. They shared an amniotic sac in the womb, a rare condition that affects about 1 percent of all twin pregnancies in the United States, and they were delivered through cesarean section at 32 weeks gestation.

“We feel blessed,” said Gregory Walker, who spent time this afternoon with the babies in the Neonatal Intensive Care Unit at UC Davis Children’s Hospital, in a press release. “The rarity of this particular type of twins is 1 in 40,000 to 1 in 65,000 births. We feel very special.”