A population-based study of prognostic factors related to major disability in very preterm survivors

Objective: This study was conducted to determine the rates and risk factors for major disability in very preterm survivors born to residents of Nova Scotia, Canada between 1992 and 1996. Study Design: A cohort study was conducted of all 355 infants born to Nova Scotia residents between 22 and 30 weeks gestation. Major disability was defined by mental development index <70, moderate or severe cerebral palsy, bilateral visual acuity <20/200, or deafness requiring bilateral hearing aids. Logistic regression analysis was used to determine which factors were significantly associated with major disability. Results: Of the infants who survived 1 year had follow-up data, 21 (8.3%) developed a major disability. Cystic periventricular leukomalacia (PVL), hypernatremia and surgery requiring general anesthesia were independently associated with the development of a major disability. Conclusion: This study confirms the association between cystic PVL and major disability observed in other studies. Surgery and hypernatremia will be important to verify in future studies since preventive measures may be possible.