The effect of prenatal smoke exposure on child neuropsychological function: a prospective mother–child cohort study

ABSTRACT

Objective: To study prospectively the effect of prenatal smoke exposure (PSE) on child neuropsychological function and intelligence quotient (IQ).

Background: PSE has been associated with adverse effects on child neurodevelopment. However, some studies reported that these associations disappear after adjustment for potential confounders.

Methods: A cohortof 248 mothers-child dyad was followed from the first trimester of pregnancy until children were 7.5 years old. PSE was recorded during pregnancy by questionnaire and plasma cotinine. The Wechsler Intelligence Scale for Children, the Neuropsychological Assessment of Executive Functions for Children (ENFEN) and the School Neuropsychological Maturity Questionnaire were administered at 7.5 years of age. The effect of PSE on child IQ and neuropsychological function was assessed with ANCOVA, adjusting for obstetric, neonatal and sociodemographic factors.

Results: Children whose mothers smoked throughout pregnancy scored lower in interference (ENFEN) compared to unexposed children (F = 4.1; p = .008). The results showed no differences in other executive functions, verbal and visual memory and IQ between the PSE groups.

Conclusion: PSE had little effect on child neuropsychological outcome and was limited to mental flexibility. Nevertheless, these findings support further efforts aimed at encouraging mothers to quit smoking in pregnancy.

KEYWORDS:

• Prenatal smoke exposure (PSE)
• second-hand smoke (SHS) exposure
• executive function (EF)
• neuropsychological function
• intelligence quotient (IQ)

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

Comisión Interministerial de Ciencia y Tecnología, SAF2005-05096; Instituto de Salud Carlos III, Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica y el Instituto de Salud Carlos III – Fondo de Investigaciones Sanitarias (cofinanced by FEDER), [10/00035, 13/02500]; [16/00506]; IISPV, [2010/21]; Centros de Investigación Biomédica en Red CIBERobn; AGAUR SGR [2009-1237, 2014-332]; Italfarmaco S.A. Spain.