The Need for Better Followup Studies on Prematurity

By Helen Harrison

The state of preemie follow-up, especially in the US, has been shocking, there's just no other "nice" way to put it. Here is an excerpt from a chapter I recently contributed to a book entitled "Infant Development and Risk" 2nd Edition eds Widerstrom et al., Paul Brookes Publishing Co., 1997:

Relatively few survivors of the NICU receive comprehensive long-term follow-up to determine the outcomes of neonatal treatment (Escobar, 1992). Most existing follow-up studies have been criticized for the small numbers of infants followed, the short duration of follow-up, inconsistencies in reporting and defining disabilities, the absence of control groups, and the many children who are 'lost to follow-up' -- all are factors that tend to bias outcome statistics toward optimism. (Aylward et al, 1985; Collin et al, 1991; Escobar, 1992 (3); Gross et al, 1992; Wariyar and Richmond, 1989)."

Dr. Gabriel Escobar (with Kaiser Permanente in California) has done a meta- analysis of all English language follow-up studies from the 1960s through the early 1990s. He found 1136 references to very low birthweight outcomes but could only identify 111 studies that met minimum requirements for a scientifically valid sample (that is, studies that did not exclude infants on a non-random basis).

Escobar wrote: "This may seem like a lot of studies -- the total number of births was 20,099 -- but closer inspection revealed that only 7000 or so infants were actually followed for more than 12 months. This means that, since 1960, on the average, only about 250 such infants were followed annually; [however] in the United States [there are] between 35,000 and 40,000 such births per year."

Escobar also points out that many studies do not investigate or list problems that would be of great concern to parents, such as cerebral palsy, and that most studies end too early to diagnose relatively serious problems, such as retardation.

However, that situation is changing. There are a number of well-conducted large studies currently underway in the US, Canada, the UK, Australia and elsewhere. New data is coming from these preliminary studies which shows prematurity has a far greater impact on behavior, cognition, motor skills, sensory capabilities and later health than has been previously recognized (at least among the general population of physicians.)

One of my challenges in rewriting The Premature Baby Book (which I'm currently working on during those 5 minutes or so each day when I'm not online) is trying to figure out how to present this new, not-very-optimistic data to parents in ways that won't be totally overwhelming. (The information in the first edition was disturbing enough to some parents!) So it is a constant tug of war between presenting the information with total honesty and trying to preserve what's left of the sanity of new preemie parents.

Last spring I was preparing for a meeting in Amsterdam with the PORT Project (premature outcomes research team), an international group of neonatologists and psychologists who are looking at school-age outcomes of premature infants born weighing less than 1500 grams, with particular emphasis on those weighing below 1000 grams. I am a consultant to this group, and I asked preemie-child members at the time for permission to compile and forward their posts to the PORT Group researchers. I hoped to give the doctors an idea of the sorts of concerns that were important to us as parents, as opposed to the sometimes arbitrary categories used by clinicians. I wanted the doctors to understand how our children's prematurity impacts their lives in practical ways. I wanted to emphasize the actual functioning of the children as opposed to whether or not they fell into some strictly defined category. For example, many of our children have learning problems but they may not fit the definition of "learning disability" used by a particular school system or a particular follow-up study. Many of our children have significant motor problems that don't meet the criteria of CP as used by certain follow-up clinics and physicians, and so forth.

They were extremely interested and impressed with what all of you had to say. (One doctor suggested I forget about the second edition of my book for a while and just write about school-age preemie behavior based on these quotes!)

References:

Aylward et al. Who goes and who stays: Subject loss in a multicenter, longitudinal follow-up study. Developmental and Behavioral Pediatrics.1985;6:3-8.

Collin et al. Emerging developmental sequelae in the 'normal' extremely low birth weight infant. Pediatrics. 1991;88:115-120.

Escobar GJ. Prognosis of surviving very low birthweight infants: Still in the dark. British Journal of Obstetrics and Gynaecology. 1992;99:1-3.

Gross et al. Impact of a matched term control group on interpretation of developmental performance in preterm infants. Pediatrics. 1992;90:681-687.

Wariyar and Richmond. Morbidity and preterm delivery: The importance of 100% follow-up. The Lancet. 1989:1(8634), 387-388.

Helen Harrison is the well known author of The Premature Baby Book, often referred to as the "Bible of Prematurity" by older preemie parents. These observations are excerted with permission from posts to the prematurity parents support internet mailing lists on prematurity: Preemie-child and Preemie-L.

Prematurity Research