Delivered at 26 weeks via an emergency Cesarean section in the Maxine Dunitz Children’s Health Center at Cedars-Sinai Medical Center in California, little Silas Johnson was born completely enclosed in his amniotic sac.

Dr. William Scott Binder, a neonatologist working at Cedars-Sinai Medical Center has over 10 years’ experience taking care of newborns yet still could not help but be in awe during Silas’s birth last December. The infant was born “en caul,” that is, still completely enclosed in his amniotic sac, and today, at only a few weeks old, Silas has already become an online sensation as the world admires the photos of his fascinating birth.

“It was a moment that really did, even though it’s a cliché, we caught our breath. It really felt like a moment of awe,” Binder told CBS Los Angeles. “This was really a moment that will stick in my memory for some time.”

silias 2
En caul births are estimated to occur in less than one in 80,000 childbirths, Cedars-Sinai said. Photo courtesy of Cedars-Sinai Medical Center

Although the moment lasted just seconds before doctors needed to burst the amniotic sac to allow Silas to breathe oxygen, the quick photography skills of Binder have allowed the world to see what he and his team witnessed in the delivery room. In fact, it wasn’t until hours later when the child’s mother, Chelsea Phillips, saw Binder’s photographs that she even became aware of the extraordinary circumstances surrounding her delivery.

“It was definitely like a clear film where you could definitely make out his head and his hair. He was kind of in a fetal position and you could see, like, his arms and his legs curled up,” Phillips told CBS. “It was actually really cool to see.”

Normally, during birth, the amniotic sac breaks and fluid rushes out, which is where the term “breaking water” comes from. Sometimes the sac, known as the caul, is still partially attached to a child during birth, but in an en caul birth the amniotic sac is still entirely enveloping the newborn child.

En caul births are usually harmless, and the caul is soon removed by either the midwife or doctor involved in the delivery. Throughout history those born still enclosed in these sacs have been associated with good luck and predicted to be destined for greatness. Cauls have come to be regarded as a good luck talisman for sailors and were once sold by women for great sums of money to men about to set bark on a long sea trip.

En caul births are more common in premature deliveries like Silas's, but are usually not seen in C-sections where the scalpel tends to pierce the sac. Baby Silas was kept in the neonatal care unit for a few weeks has reportedly gone home in perfect health.

Correction: In a previous version of this story it read that Dr. Binder had over 10 years of experience delivering children as a neonantologist. It has now been corrected to read that Dr. Binder has had over 10 years of experience taking care of newborns.