Pediatricians track survival of the ‘tiniest’ of preemies

There are many reasons for a premature birth: sickness or physical anomolies in the mother or fetus; more childbearing among women of “advanced maternal age”; more women carrying multiple fetuses, especially as a result of in-vitro fertilization.

In 40 percent of premature births, the cause is “unknown,” according to the March of Dimes, which started a Prematurity Campaign in 2003.

While data is collected about low birthweights in general, there is nothing specific for the very smallest babies, Dr. Bell told The Washington Times.

In 2000, he founded the Tiniest Babies Registry to gather information about the rarest of infants — those weighing less than 400 grams who lived past the point of hospital discharge.

In the beginning, he said, the registry identified 15 patients, including two born in the 1930s. (One baby was weighed on a grocery scale.) Today’s tally includes 80 patients from the United States and 30 from nine other countries. The smallest infant started life at 260 grams, or less than 10 ounces.

The vast majority of these tiny infants are girls, although the reasons for this are not understood.

“Our best guess is that something about the hormonal milieu affects the maturation rate of the lungs and other key organs,” said Dr. Bell, who teaches at the Department of Pediatrics at the University of Iowa. “Premature girls mature faster than boys, just as preadolescent girls typically reach puberty at a younger age than boys.”

In the Pediatrics study on outcomes of babies born before 25 weeks’ gestation, some 411 babies born between 1999 and 2001 were compared with 405 babies born between 2002 and 2004.

“Adverse outcomes … were common” in both groups, with cerebral palsy in more than 10 percent of the babies, and neurodevelopmental impairments in more than half, the study found.

Care for these miracle babies is costly — in 2005, the Institute of Medicine estimated that the overall cost of preterm births in the U.S. was $26 billion, or $51,600 for every child.

There are also other concerns: In a hospital intensive-care unit filled with sick, needy babies, is it right that most of the care goes to one very sick infant? Who should decide what kind of care is given for a very premature baby? Who should pay for this care? How should these decisions be made?

In the United Kingdom, a council has decided, essentially, that intensive care should not be given to babies born before 22 weeks’ gestation, and rarely to babies born at 23 weeks. Care is readily given to preemies born at later weeks because they have demonstrably better chances for survival and health, the U.K. guidelines said.

In the United States, “I don’t think we’ll get a consensus anytime soon” on national guidelines for the care of preterm infants, but the same questions are being asked all the time, said Dr. Brian S. Carter, professor of Pediatrics (Neonatology) at Vanderbilt University School of Medicine in Nashville, Tenn.

So far, the United States is seeing improvements in survivability in its preterm babies — the fact that so many of the tiniest babies in the registry are U.S.-born underscores that point, he said.

But as studies show, there is not a significant decrease in morbidity, or negative physical and mental outcomes, for babies born before 25 weeks, he said.

One promising avenue is to intensify care for pregnant women so they can sustain their pregnancies longer, especially past 25 weeks, Dr. Carter said. There can be a significant difference at between being born at 22 weeks and 0 days, and 22 weeks and 6 days, he said. “Every day matters.”