She was long overdue.

When it comes to having a baby girl the odds are usually 50-50. Unless you’re a part of this Michigan family. Then, the odds are about 1 in a million (give or take).

For over a century, the Clark family has only welcomed boys. The last time a baby girl was born into the family was 138 years ago.

That is, until now.

The Gender Reveal Party

gender reveal party
Andrew & Carolyn Clark|Facebook

Andrew Clark comes from a long line of male-dominated births, dating back to his great-great-grandfather.

So when he started dating his now-wife, Carolyn, he warned her about the long-standing tradition, telling her, “Oh, we don’t have girls. Legitimately, we have not had a girl in our direct line in over 100 years.”

Challenge accepted.

With the odds stacked against her the size of Mount Everest, Carolyn was determined to end the daughter drought.

Not surprisingly, their first child was a boy, Cameron, who is now 4 years old.

After suffering a miscarriage, the couple learned they were expecting again. “We honestly didn’t care if we were having a boy or girl at this point,” Carolyn told GMA. “We just were thankful to be pregnant and just praying for a healthy pregnancy and a healthy baby.”

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In September, family and friends gathered together for a gender reveal party. They were each given a cookie containing either blue or pink frosting. Everyone assumed it would be blue.

It wasn’t. It was pink. The Clarks were finally having a girl.

The response to the baby news? Shock and awe. And a whole lot of jumping and screaming.

“We kept it a secret to ourselves as well. So I just assumed it was going to be blue in the center of the cookies and it’d be another boy in the lineage,” Andrew shared. “I was shocked. I think I just stared at the center of that cookie like, it’s really pink. So it was a good surprise for us.”

Birth of Baby Girl Breaks a Century-Long Tradition

Even with confirmation from their doctor, the Clarks still couldn’t quite believe their luck. Throughout the pregnancy, they were plagued with doubts.

“I think every ultrasound she was like, ‘Double check that it’s a girl. I don’t believe in it,'” Andrew said.

Well, turns out, it was a girl. Audrey Marie Clark was born on March 17 — St. Patrick’s Day — with the luck of the Irish clearly on her side.

Weighing in at 6 pounds 8 ounces, Audrey is a healthy bundle of joy and the family couldn’t be more thrilled.

“It was just joy, you know, just that she was here and healthy,” said Carolyn. “It made it even more special that it was a girl because it was like, you were worth the wait and all the struggles.”

What Are the Odds?

While the Clarks are certainly an anomaly, the scales are actually slightly tipped in favor of having a boy, according to science.

The World Health Organization reports that there is a 51% chance of having a boy and a 49% chance of having a girl.

Researchers from Newcastle University in England believe that this might be due to a gene that controls the balance of X- and Y-carrying sperm.

After studying more than 927 family trees dating back to the 1600s, they discovered that the sex ratio for families followed the father’s side, not the mother’s side.

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“Men inherit a tendency to have more sons or more daughters from their parents. This means that a man with many brothers is more likely to have sons, while a man with many sisters is more likely to have daughters.”

In other words, it’s all in the father’s genes. Men carrying a gene that leads to their sperm having more Y chromosomes have more sons.

It seems to be the case in the Clark family.

Boy or girl, the Clarks, like all parents, are just happy to have a healthy baby. The fact that they were the ones to finally break the 138-year streak is “icing on the cake.”

But even so, they may want to start buying lottery tickets. Seems the odds are in their favor.