Accuracy of the Bayley-II mental development index at 2 years as a predictor of cognitive impairment at school age among children born extremely preterm

UMMS Affiliation

Department of Psychiatry

Publication Date


Document Type



Female Urogenital Diseases and Pregnancy Complications | Nervous System | Pediatrics | Psychiatry | Psychiatry and Psychology | Psychological Phenomena and Processes


OBJECTIVE: To describe the accuracy of the Bayley Scales of Infant Development-Second Edition (BSID-II) Mental Development Index (MDI) at 2 years of age for prediction of cognitive function at school age of children born extremely preterm.

DESIGN: Study participants were enrolled in the Extremely Low Gestational Age Newborn Study between 2002 and 2004. Two-thirds of surviving children (n = 795) were assessed at 2 years with the BSID-II and at 10 years with an intelligence quotient (IQ) test. We computed test characteristics for a low MDI ( < 70), including predictive value positive.

RESULTS: Almost two-thirds of children with a low MDI had a normal IQ ( > /= 70) at 10 years. Concordance between MDI and IQ was highest among children with major motor and/or sensory impairment, and when MDI was adjusted for gestational age.

CONCLUSION: Most children born extremely preterm with low BSID-II MDI at 2 years have normal intelligence at school age.


Medical research, Risk factors

DOI of Published Version



J Perinatol. 2018 Jul;38(7):908-916. doi: 10.1038/s41372-017-0020-8. Epub 2018 May 29. Link to article on publisher's site

Journal/Book/Conference Title

Journal of perinatology : official journal of the California Perinatal Association

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Link to Article in PubMed

PubMed ID