The unusual reason this man cried watching his wife give birth is moving mums everywhere.

These photos of a man watching his wife give birth have gone viral – and it’s more about the story behind the birth than the photos themselves.

Kirstie Clark, of Kirstie Perez Photography in Texas, was the birth photographer. She was there in the background, snapping away, as the woman delivered a baby boy, and her husband, in tears, looked on. Afterwards, Clark spoke to the new dad.

“I told him I captured him crying seeing his son and he said, ‘That’s not why I was crying,’” she explained on Facebook.

“Puzzled, I asked what he meant. He teared up again and said, ‘This is the first time I have seen her smile in 10 months.’”

Stunning. Image: Kirstie Clark with KPP (Kirstie Perez Photography)

The man told Clark his wife had endured an incredibly difficult pregnancy.

“He helplessly watched his wife vomit profusely for 285-plus days. He witnessed her lose 30 pounds [more than 13kg] in pregnancy not being able to nourish herself due to hyperemesis gravidarum and preeclampsia.

“She was hospitalised four times for dehydration throughout her pregnancy. Ate more dinners on the front steps of their home than he could count because any scent literally made her ill.

“After months of simply being there for her as much as possible, he supported her during birth.”

The happy family. Image: Kirstie Clark with KPP (Kirstie Perez Photography)

Clark wanted to share the photos and the story with other people, and she had a message.

“Men, please understand how powerful your empathy can be.

“To all of the mothers who have traumatic pregnancies and still find a way to smile… thank you for sacrificing yourself and enduring to bring your precious child into the world. That is no easy feat.”

Clark tells Mamamia that the woman “graciously” shared the photos, and the response has been “remarkably overwhelming”.

“I think people connected to this because it shows truth – the ugly and devastating side to pregnancy for some mums that go through hell for their children without warning,” she says. “Women all over the world feel heard and validated through my client’s birth.

“It’s been amazing. So many women feel heard and can possibly heal from knowing they are not and were not alone.”