An Indian woman has given birth to five baby girls. Quintuplets are extremely rare and are likely to occur naturally only once out of tens of millions of births.

Amita Kumari, 27, gave birth to the girls at Rajendra Institute of Medical Sciences in eastern Jharkhand state on Monday.

The hospital made the announcement on Twitter alongside a picture of the babies.

“A woman from Chatra has given birth to five children at the department of obstetrics and gynecology at RIMS. The babies are under the supervision of doctors in the neonatal intensive care unit. A successful delivery was conducted under the leadership of Dr Shashi Bala Singh,” the hospital said.

Doctors performed an ultrasound and found the woman was carrying five fetuses. She gave birth naturally at seven months.

Dr Rajiv Mishra, a professor in the department of neonatology at the hospital, said that three of the babies were kept under observation at the hospital’s neonatal intensive care unit while two were shifted to another hospital because of limited resources.

“The first, third, and fifth baby are with us. The first and third babies weigh 1.1 kilograms each, and the fifth one weighs 750 grams. They are premature babies, very tiny,” Dr. Mishra told The National.

The other two babies weigh 900 grams each.

Dr. Kiran Shankar Das, assistant professor at the neonatal department, said that the babies would require at least 45 days to two months of observation.

“They were born at 27 weeks of gestation. One baby is on a ventilator, and the other two are stable. Their survival chances are 50 percent to 60 percent,” he said.

While twins, triplets, quadruplets, and quintuplets have become more common with IVF treatment, Dr. Das said that this was not the case this time.

“The mother was on fertility treatment, she was on ovulation-inducing drugs, but not IVF,” he said.

“This is the first case of quintuplets being born in the hospital. We delivered quadruplets a few months back in the hospital,” he said.

The chances of conceiving quintuplets naturally are extremely rare – about one in 55 million births. There have, however, been a handful of cases of such births in the country.

In 2015, a woman in northern Punjab gave birth to five girls in 10 minutes.

And a 25-year-old woman in Jaipur in western Rajasthan gave birth to five babies, although one was stillborn.