A new report sponsored by the World Health Organization and several child-welfare charities says Pakistan has one of the world's highest rates of preterm birth, with nearly 16 for every 100 babies born.
Only India and China had a greater number.
Belarus had the lowest preterm birth rate of 184 countries included in the report, with just over four per 100 babies born.
The report estimates that 15 million babies are born early every year, with more than 1 million dying.
It also says that 75 percent of those deaths could be avoided through inexpensive maternal and neonatal health care.