The Outcomes of Very Preterm Infants: Is It Time to Ask Different Questions?

Abstract

* Abbreviations: CP — : cerebral palsy NDD — : neurodevelopmental disability VPT — : very preterm The birth of a very preterm (VPT, <32 weeks) infant is a medical emergency associated with life-threatening complications and high costs of care. Decision-making by providers and parents requires information on possible outcomes. Here we describe the evolution of outcomes assessments for VPT infants, their limitations, and alternative strategies. Much of the literature on the follow-up of very low birth weight (<1500 g) or VPT infants focuses on neurodevelopmental disability (NDD; ie, intelligence/developmental quotients generally <70); cerebral palsy [CP], and blindness/deafness). Characterizing the risk of these conditions followed adding birth weight to the US birth certificate in 1949. An early investigator, Lillienfeld,1 demonstrated higher rates of prematurity among children with CP, mental deficiency, and epilepsy than in children without these conditions. These findings were reinforced in the large, prospective Collaborative Perinatal Study.2 The large size and rigorous methods informed the assessment ages and content of subsequent follow-up studies, allowing later investigators to “benchmark” their results. Lilienfeld1 postulated that certain events in utero lead to an array of outcomes including spontaneous abortion, stillbirth, premature delivery, and infant morbidity. His intent was to underscore the diversity of potential outcomes—a spectrum of reproductive casualty. Later investigators hypothesized that this spectrum suggested a potential trade-off between survival and disability, that is, a relatively fixed quantum of adverse outcomes in which increased survival came at the expense of increased morbidity. The increased survival of premature infants that underlay the decline in neonatal mortality beginning in the late 1960s stimulated a steady … Address correspondence to Marie C. McCormick, MD, ScD, Sumner and Esther Feldberg Professor of Maternal and Child Health, Department of Social and Behavioral Sciences, The T.H. Chan Harvard School of Public Health, 677 Huntington Ave, Boston, MA 02115. E-mail: mmccormi{at}hsph.harvard.edu