Are observed associations between a high maternal prepregnancy body mass index and offspring IQ likely to be causal?
ALSPAC
child health
cognition
obesity
pregnancy
Journal
Journal of epidemiology and community health
ISSN: 1470-2738
Titre abrégé: J Epidemiol Community Health
Pays: England
ID NLM: 7909766
Informations de publication
Date de publication:
10 2019
10 2019
Historique:
received:
08
02
2019
revised:
18
06
2019
accepted:
06
07
2019
pubmed:
31
7
2019
medline:
15
12
2020
entrez:
31
7
2019
Statut:
ppublish
Résumé
A high maternal prepregnancy body mass index has been associated with lower offspring IQ, but it is unclear if the relationship is causal. To explore this, our objectives were to compare maternal and paternal estimates and to assess whether certain factors mediate the association. We analysed data from the Avon Longitudinal Study of Parents and Children, which initially recruited 14 541 women residing in Avon, UK, with an expected date of delivery in 1991-1992. Data were collected during and after pregnancy by questionnaire, medical record abstraction and clinical assessment. At approximately 8 years of age, psychologists administered an abbreviated form of the Wechsler Intelligence Scale for Children-III. We fit multivariable logistic regression models to estimate parental prepregnancy obesity and overweight-offspring IQ associations. Counterfactually defined indirect (mediated) effects of maternal prepregnancy obesity on offspring IQ were estimated through path analysis. Among 4324 mother-father-child triads and using normal weight as the referent, we observed consistently stronger associations for maternal prepregnancy obesity and offspring performance IQ (eg, adjusted β (95% CI)=-3.4 (-5.7 to -1.2) vs -0.97 (-2.9 to 0.96) for paternal obesity). The indirect effects of maternal obesity on offspring IQ through pathways involving gestational weight gain and duration of breastfeeding were small but significant. Our findings are consistent with a weak biologic effect of maternal adiposity in pregnancy on offspring performance IQ. Given the growing prevalence of obesity worldwide, more evidence is needed to resolve the correlation versus causation debate in this area.
Sections du résumé
BACKGROUND
A high maternal prepregnancy body mass index has been associated with lower offspring IQ, but it is unclear if the relationship is causal. To explore this, our objectives were to compare maternal and paternal estimates and to assess whether certain factors mediate the association.
METHODS
We analysed data from the Avon Longitudinal Study of Parents and Children, which initially recruited 14 541 women residing in Avon, UK, with an expected date of delivery in 1991-1992. Data were collected during and after pregnancy by questionnaire, medical record abstraction and clinical assessment. At approximately 8 years of age, psychologists administered an abbreviated form of the Wechsler Intelligence Scale for Children-III. We fit multivariable logistic regression models to estimate parental prepregnancy obesity and overweight-offspring IQ associations. Counterfactually defined indirect (mediated) effects of maternal prepregnancy obesity on offspring IQ were estimated through path analysis.
RESULTS
Among 4324 mother-father-child triads and using normal weight as the referent, we observed consistently stronger associations for maternal prepregnancy obesity and offspring performance IQ (eg, adjusted β (95% CI)=-3.4 (-5.7 to -1.2) vs -0.97 (-2.9 to 0.96) for paternal obesity). The indirect effects of maternal obesity on offspring IQ through pathways involving gestational weight gain and duration of breastfeeding were small but significant.
CONCLUSION
Our findings are consistent with a weak biologic effect of maternal adiposity in pregnancy on offspring performance IQ. Given the growing prevalence of obesity worldwide, more evidence is needed to resolve the correlation versus causation debate in this area.
Identifiants
pubmed: 31358534
pii: jech-2019-212257
doi: 10.1136/jech-2019-212257
doi:
Types de publication
Journal Article
Research Support, Non-U.S. Gov't
Langues
eng
Sous-ensembles de citation
IM
Pagination
920-928Subventions
Organisme : Medical Research Council
ID : G9815508
Pays : United Kingdom
Organisme : Medical Research Council
ID : MC_PC_15018
Pays : United Kingdom
Organisme : Medical Research Council
ID : MC_PC_19009
Pays : United Kingdom
Informations de copyright
© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.
Déclaration de conflit d'intérêts
Competing interests: None declared.