An estimated 48,000 babies are expected to be born in squalid refugee camps in Bangladesh where hundreds of thousands of Rohingya Muslims fled violence from Buddhist-majority Myanmar.

The global charity, Save the Children, revealed the new figures on Friday, showing that the Rohingya families, who rely on food rations in overcrowded flimsy tents, are expected to give birth to these babies in 2018.

Most of the children will be born without health facilities, and will be at inexorable risk of getting sick, undernourishment and thus putting them under threat of dying before they reach five years of age, the agency said in a statement.

"We're expecting about 130 live births per day across 2018. Most babies will likely be born at home in basic tents, in part because of the shortage of quality, 24-hour health facilities able to handle and manage basic emergency obstetrics, as well as challenges accessing health care," Save the Children's health adviser in Cox's Bazar, Rachael Cummings, said.

According to UN estimates, more than 655,000 Rohingya Muslims crossed into Bangladesh after the Myanmar army launched a crackdown on suspected Muslim insurgents blamed for carrying out attacks on security posts in restive Rakhine state on August 25.

Cummings termed the possible disadvantages for the babies "truly heartbreaking," saying they would battle the odds stacked against them.

The charity urged the international community to scale up assistance for the expectant mothers and their babies who will be in dire need of medical care.