A Michigan couple who already had 12 sons have kept the all-male streak alive with the birth of boy No. 13 on Wednesday.

Jay Schwandt told The Associated Press that his wife Kateri gave birth Wednesday morning, four days after her due date.

The couple had said they were sticking to the tradition of not knowing the baby's sex ahead of time.

The 40-year-old father confirmed the birth in a text message to The Associated Press, saying the family will release details Thursday on ABC-TV's "Good Morning America."

"Ok, so the boys know now!" Schwandt said in a post on Facebook. "It's a BOY! Now we need to choose a name! BLESSED beyond belief!"

The Schwandts live in Rockford, north of Grand Rapids.

Kateri Schwandt, 40, says she has a lot of experience with large families, as one of 14 children herself.

In an interview last week, she said she finds motherhood to be "very rewarding."

"Your children are a little piece of you. Every day is Mother's Day," she told The Grand Rapids Press. "They will bring me flowers that they pick in the yard. Even if it's a dandelion, it's special because they were thinking of Mom."