In an incredible coincidence, four sisters have all managed to be born on the same date – 25th August, over a span of nine years.

None of the births were planned or c-sections, and two of the girls arrived earlier than their due dates. Amazing!

Mum Kristin Lammert, 35, gave birth to her fourth daughter, Valentina on August 25, one month early – arriving on the birthday of her sisters, Sophie, nine, Giuliana, six, and three-year-old Mia.

“The birthday of my dog that I had growing up was August 25,” Kristin told PEOPLE. “Then 10 years later, Sophia was born and we thought that was so cool. When Giuliana came, she was a little bit early. And when Mia came, she was extra early. Now Valentina’s extra, extra early. We really can’t grasp the concept ourselves.”

Kristin share the news of her newest daughter’s birth on social media, calling her daughters the Grand Slam Birthday Lamms.

“Yes, it happened to happen, yet again!!! I can guarantee you that nobody is more shocked than us right now… We are convinced that she wanted to join the big birthday party, so she decided to come about a month early!! She’s so healthy and strong!”

According to the family, the odds of having four girls all born on the same date is 1 in 1.285 billion.

Baby Valentina ended up coming earlier than her September 25 due date, after Kristin started experiencing worrying symptoms on her last day at work on August 23. Tests revealed she had severe preeclampsia.

“The only cure for preeclampsia is delivery of the baby,” Kristin explained. “So they hooked me up to a bunch of things and they were monitoring myself and the baby to make sure I was going to be okay. So they couldn’t send me home.”

Kristin and her husband Nick realised on August 24, that it was looking like their fourth bundle of joy would indeed arrive on August 25.

“My husband and I looked at each other and started cracking up,” Kristin said. “We cannot believe this is going to happen again.”

“But we also knew that there was no chance that they were going to allow me to continue being pregnant past the 25th, because at that point she had to come. We already knew that they weren’t going to let me leave until the baby was born. So if she didn’t come on her own, it was going to have to possibly be a C-section. But the chances of them allowing me to stay pregnant an additional 24 hours were slim.”

Valentina arrived the next day, and the little fighter was well enough to stay out of the NICU.

“It’s miraculous that she’s here safely, thriving and growing as she should be,” Kristin said. “It’s miraculous that I’m healthy and alive. And then when you throw in the shared birthday factor, that’s miraculous and so unlikely in itself, and blows my mind every time I realise our reality.”

Do you have any amazing coincidences in your family? Let us know in the comments below.