Even when a baby comes bellowing into the world at a hearty eight pounds, parents worry about its vulnerability. This worry is compounded for parents of preemies -- tiny babies weighing 5 pounds, 8 ounces, or less, typically born before 37 weeks.
About one in 12 U.S. infants are born with low birth weight, which carries the risk of infection, developmental delays, and even death, according to the March of Dimes. In fact, the number of babies born during the late preterm period of 34 to 36 weeks has risen 20 percent since 1990, according to the U.S. Centers for Disease Control and Prevention.
Here we walk you through the various causes of low birth weight in hopes that a greater understanding of the problem can help in its prevention, starting with No. 1 low birth rate risk: multiple pregnancy.