Difficult temperament, breastfeeding, and their mutual prospective effects: the Norwegian Mother and Child Cohort Study.
OBJECTIVE
(1) To examine the extent to which difficult temperament and breastfeeding are associated at child age 6 and 18 months. (2) To examine longitudinally whether breastfeeding has an influence on temperament development or whether difficult temperament has an influence on continued breastfeeding.


METHODS
This prospective study is part of the Norwegian Mother and Child Cohort Study, which targets all women giving birth in Norway; the present sample comprises 30,466 children. Mothers reported on child difficult temperament at child age 6 and 18 months and on breastfeeding from 0 to 6 months and from 6 to 12-14 months. Prospective associations between breastfeeding and difficult temperament were examined using structural equation modeling, with comparison of cross-lagged pathways. All analyses were adjusted for background variables that are relevant for breastfeeding.


RESULTS
At 6 months, children with more difficult temperament were significantly less likely to have been "fully" breastfed (exclusively and predominantly breastfed) for the recommended period of 6 months (unadjusted point-biserial correlation r pb = -.15; adjusted r pb = -.11). At 12 to 14 months, there was no longer an association between difficult temperament and (continued) breastfeeding after adjusting for background variables, temperament, and breastfeeding at 6 months. The cross-lagged analyses of the longitudinal pathways yielded negligible effects of difficult temperament on later breastfeeding and of breastfeeding on later temperament.


CONCLUSIONS
Difficult temperament and reduced breastfeeding seem to be associated only during the first half-year of the child's life. After that, we found no evidence of codevelopment between difficult temperament and breastfeeding.
Niegel
Susan
S
Norwegian Institute of Public Health, Division of Mental Health, Department of Psychosomatics and Health Behavior, Oslo, Norway. susan.niegel@fhi.no
Ystrom
Eivind
E
Hagtvet
Knut A
KA
Vollrath
Margarete E
ME
D001942:Breast Feeding / Q000706:statistics & numerical data*; D002675:Child, Preschool; D015331:Cohort Studies; D004644:Emotions / Q000502:physiology; D005260:Female; D005865:Gestational Age; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009664:Norway; D011247:Pregnancy; D011446:Prospective Studies; D002666:Psychology, Child; D011795:Surveys and Questionnaires; D013694:Temperament / Q000502:physiology*; D013997:Time Factors; D044465:White People