PHOTOS: The amazing water birth of twins

Robin Baker has witnessed the arrival of more than 70 babies, but the US photographer describes this birth as "one of the most incredible moments" of her career. It's easy to see why.

The incredible images show a father helping his wife deliver twins at home in their bathtub.

The babies, a boy and a girl, were born so quickly that the unnamed couple's birth team did not arrive in time for the birth. The mother and father spoke to a doctor on the phone as they prepared for their babies' arrival. 

Fortunately the parents had delivered their older child at home just two years earlier and knew what to do second time around. 

"In between contractions and taking photographs, I was focused on helping them prepare a space to birth," Baker told US PopSugar about the unique delivery.

"I'm also an experienced home birther, so I knew what needed to be done. The parents were calm, peaceful, and brought their babies into the world effortlessly!"

To make the birth even more special, the second baby to arrive was born en-caul, or still inside the amniotic sac. This only happens in about one in every 80,000 deliveries.

"They had 30 minutes of bonding time with Baby A before Baby B made his way into his fathers hands still en-caul," Baker explained.

"The mum reached down and removed the sac, and Dad turned the baby to release the nuchal cord and then handed him to mum. The atmosphere was peaceful and joyous. 

"It was truly one of the most incredible moments of my career.

"Since so many twins are born in the operating room, this birth was very special. Women are incredible when they follow their body's natural instincts."