It wasn't an unusually busy weekend for the delivery unit of the University of Minnesota Medical Center, where 19 babies were born between 9 p.m. Friday and 7 a.m. Monday.

But somewhere along the line, nurses noticed a trend.

Boy, boy, boy, boy, boy, boy ... boy?!

In a run that defied odds, the Minneapolis hospital assisted with 19 consecutive births of baby boys.

"They noticed [Saturday night] after about seven babies, and then they just kept watching," said Lisa Archer, a nurse manager for the labor and delivery unit.

The run ended around 7:30 a.m. Monday with the birth of Ladan Ibrahim, the second daughter for Mohammed Guled and Naima Bashir. It just so happens that Guled is the chief executive of a Bloomington-based company that sells diapers. He was so awed by the improbable streak that he decided to donate three months' worth of diapers to the 19 families with new baby boys.

Assuming that each birth has a 50-50 chance of producing a boy, the probability of a streak like Fairview's is one in 524,288.

Of course, gender isn't quite 50-50 when it comes to births. Historically, slightly more births result in boys than girls, both statewide and nationwide. (In 2009, for example, Minnesota had 34,995 male single births and 33,017 female single births.)

Archer said nothing other than random chance explains the improbable weekend.

"We don't run a special on boys," she joked.

Hospital officials couldn't recall a comparable streak in the past.

Guled and Bashir didn't know the gender of their baby until she arrived -- nor did they know about the streak until one member of the delivery team exclaimed, "Wow, it's a baby girl. Finally!"

The boy's name they had agreed upon means "victory," he said. But Ladan means "special."

"It turned out," Guled said, "to be a really special day."

Jeremy Olson • 612-673-7744