Two blood-building drugs injected soon after birth may give premature babies a lasting long-term edge, boosting brain development and IQ by age 4, a first-of-its-kind study found.

The study was small but the implications are big if larger, longer studies prove the drugs help level the playing field for these at-risk newborns, the researchers and other experts say.

Preemies who received the medicines scored much better by age 4 on measures of intelligence, language and memory than those who did not. The medicine-receiving group’s scores on an important behavior measure were just as high as a control group of 4-year-olds born on time at a normal weight.

The results are “super exciting,” said Robin Ohls, the lead author and a pediatrics professor at the University of New Mexico. She said it is the first evidence of long-term benefits of the drugs when compared with no blood-boosting treatment.

Although the treated babies didn’t do as well as the normal-weight group on most measures, their scores were impressive and suggest greater brain development than the other preemies, Ohls said.

They scored about 12 points higher on average on IQ tests than the untreated infants but about 10 points lower than the normal-weight group. On tests measuring memory and impulsive behavior, the treated babies fared as well as those born at normal weight.

Here is how those differences would show up in a preschool setting: The untreated group would be the children who struggle a little in class, while those who received the medicines would do well — but not as well as those born at a normal weight, said Michael Schreiber, an expert in neonatal-perinatal medicine and pediatric critical care at the University of Chicago’s Comer Children’s Hospital.

Survival of extremely tiny preemies has improved significantly in the past 50 years, but treatment for medical problems and developmental delays linked with prematurity has not kept pace, Schreiber said. He was not involved in the study.

He said larger studies that include more diverse patient populations are needed to determine whether the drugs can help a broader range of preemies.

The study involved 53 children, most white or Hispanic, born more than a month premature and weighing less than three pounds at hospitals in Colorado, New Mexico and Utah. Two dozen normal-weight children also were included.

Results were published Monday in the journal Pediatrics.

Shortly after birth, the preemies were randomly assigned to receive injections of either erythropoeitin three times weekly, darbepoetin once a week for several weeks, or no treatment. The drugs build red blood cells and are approved to treat anemia caused by cancer treatment or resulting from other conditions.

Preemies lack the ability to make new red blood cells and often need frequent blood transfusions to replace blood taken for lab tests. The drugs, in doses similar to the ones studied, are sometimes used to try to reduce their need for transfusions.

The drugs can increase endurance by boosting oxygen levels in the blood and have been implicated in some doping scandals.

Sandra Juul, a pediatrics professor at the University of Washington, is leading a larger multi-center study of both drugs in preemies and said it is too soon to recommend the medicines for treating developmental delays.

Still, because almost half of infants born extremely early have significant developmental problems, any treatment that could improve their lives “is incredibly important,” Juul said.

— Associated Press