Another boy was delivered by a doctor who is now his great-grandmother, hospital officials said.
New kids came to parents at about 12:00 a.m. -- give or take a second or more -- at Sutter Delta Medical Center in Antioch and Alta Bates
Summit Medical Center's campus in Berkeley and the Santa Clara Valley Medical Center in San Jose, said spokespersons for each facility.
At Sutter Delta, 20-year-old Kara Jeter, of Bakersfield, said she drove to Antioch last Wednesday with her boyfriend fully expecting that her grandmother who works at the hospital, Dr. Debra Stewart, would deliver her son.
In the last few days while staying at her grandma's home in Antioch, she started feeling contractions on and off until she it was time Sunday night, Jeter said.
The boy, named Harley after his 19-year-old father, Thomas Harley Sparks, was born caesarian by his great-grandmother within seconds after midnight and Jeter's grandmother had the honor of carrying him to her, she said.
"I feel special and it's something I'll get to tell my son when he gets older," Jeter said, adding that she also was "hoping for a New Year's baby.
The boy weighed 8 pounds, 2.5 ounces and was 21 inches long, according to hospital spokeswoman Angela Lombardi.
Christina Susim, 29, had a girl weighing only 4 pounds 9 ounces and 17.5 inches long seconds after the clocks reached midnight at Alta Bates' Berkeley campus, hospital spokeswoman Carolyn Kemp said.
The girl, who is yet to be named, spent only 33 weeks in the womb and was placed into the infant intensive care unit but is doing fine, Kemp said.
"It's a little early," Kemp said. "This baby was trying to be born."
At the Santa Clara Valley hospital in San Jose, a nursing shift supervisor, who declined to give her name, said that a boy was born there about three seconds after midnight.
The boy was 8 pounds, 20 inches, said the supervisor, who had no further information.
The first baby of 2013 at ValleyCare was Ahmani Trosclair, who arrived at 4:56 a.m., said Denise Bouillerce, marketing and public relations manager for the hospital.
Ahmani, the daughter of Naecionna Trosclair of Hayward, weighed 7 pounds 11 ounces at birth and measured 22 inches.