These California twins have different birth years. ‘I’ve never had this before,’ doctor says

Twins born just minutes apart in Delano will spend a lifetime explaining why their birth years don’t match, as one was born in 2017 and the other in 2018 – the first baby believed to be born in Kern County in the new year.

Joaquin Ontiveros, Jr., was born at 11:58 p.m. on Dec. 31, according to a report from 23ABC. He weighed 5 pounds, 9 ounces and was 18 inches long. His twin sister, Aitana de Jesus Ontiveros, was born at 12:16 a.m. on Jan. 1. She was 16 1/2 inches long and weighed 4 pounds, 10 ounces.

The babies were born at Delano Regional Medical Center. The parents of the twins told 23ABC the babies arrived about a month earlier than expected.

In Sacramento, the first baby of 2018 came at 12:15 a.m. at Sutter Medical Center, according to Fox40. Ignacio Calderon Pulgar, who was born a week early, weighed 8 pounds, 7 ounces and was 21 inches long with a full head of hair.

So, how rare is it for twins to be born in separate years? According to a blog post on Freakonomics by Louise Firth Campbell and Amram Shapiro, co-authors of The Book of Odds, the chances of this occurring are about one in 59,000.

“I’ve been doing this for 35 years, and I’ve never had this before,” said Seyed Tamijidi, the doctor who delivered the twins, in a bakersfieldnow.com report.

This story was originally published January 2, 2018 at 5:32 PM with the headline "These California twins have different birth years. ‘I’ve never had this before,’ doctor says."