Lifestyle during pregnancy: Neurodevelopmental effects at 5 years of age. The design and implementation of a prospective follow-up study
ABSTRACT It has been suggested that even mild exposure to alcohol, caffeine, smoking, and poor diet may have adverse long-term neurodevelopmental effects. In addition, there is evidence that timing of high exposures (e.g. binge drinking) can have particularly negative effects. This paper describes the design and implementation of The Lifestyle During Pregnancy Study addressing major methodological challenges for studies in this field. The study examines the effects of lifestyle during pregnancy on offspring neurodevelopment.
In 2003, we initiated a prospective follow-up of 1750 mother-child pairs, sampled on the basis of maternal alcohol drinking patterns from The Danish National Birth Cohort (DNBC), a study of 101,042 pregnancies enrolled 1997-2003. Data collection in the DNBC involved four prenatal and postnatal maternal interviews, providing detailed information on maternal alcohol drinking patterns before and during pregnancy, caffeine intake, smoking, diet, and other lifestyle, medical, and sociodemographic factors.
At the age of 5 years, the children and their mothers participated in a comprehensive assessment of neurobehavioural development focusing on global cognition, specific cognitive functions, and behaviour. Two new tests assessing attention and speed of information processing among children were developed, and data on important potential confounders such as maternal intelligence quotient, vision, and hearing abilities were collected. Efforts were made to standardise procedures and obtain high inter-rater reliability.
We expect that the study will illuminate the significance or lack of significance of maternal lifestyle during pregnancy and contribute to better understanding the effects of alcohol drinking during pregnancy at low to moderate consumption levels.
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ABSTRACT: Objective To study whether fertility treatment or subfertility is associated with long-term growth in the offspring. Design A prospective follow-up study including 1,773 singletons participating in the Lifestyle During Pregnancy Study at the age of 5. Setting Research centers. Patient(s) A total of 3,478 mother-child pairs were sampled from the Danish National Birth Cohort, and 1,773 completed the outcome measurements. A total of 69 children were born after fertility treatment, whereas 132 were born to subfertile parents conceiving spontaneously but after a time to pregnancy of more than 12 months. The remaining 1,572 children were born to parents conceiving spontaneously within 12 months. At the age of 5, the children participated in a follow-up including anthropometric measurements. Information on important covariates with respect to family background, maternal prenatal exposures, perinatal outcomes, and postnatal parental lifestyle characteristics were obtained from the Danish National Birth Cohort, the 5-year follow-up, and Danish health registers. Intervention(s) None. Main Outcome Measure(s) Adjusted mean differences in body weight, height, body mass index (BMI), and head circumference at age 5. Result(s) Compared with spontaneously conceived children born to fertile parents, no systematic differences were observed for body weight, height, BMI, or head circumference at age 5 in children conceived after fertility treatment or to subfertile parents conceiving spontaneously. Conclusion(s) There were no differences in child anthropometrics at 5 years between children conceived after fertility treatment or by subfertile parents compared with that of children born to fertile parents. However, children born after fertility treatment may show catch-up growth during childhood.Fertility and Sterility 10/2014; 102(4). DOI:10.1016/j.fertnstert.2014.06.048 · 4.30 Impact Factor
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ABSTRACT: Parental education and maternal intelligence are well-known predictors of child IQ. However, the literature regarding other factors that may contribute to individual differences in IQ is inconclusive. The aim of this study was to examine the contribution of a number of variables whose predictive status remain unclarified, in a sample of basically healthy children with a low rate of pre- and postnatal complications. 1,782 5-year-old children sampled from the Danish National Birth Cohort (2003-2007) were assessed with a short form of the Wechsler Preschool and Primary Scale of Intelligence - Revised. Information on parental characteristics, pregnancy and birth factors, postnatal influences, and postnatal growth was collected during pregnancy and at follow-up. A model including study design variables and child's sex explained 7% of the variance in IQ, while parental education and maternal IQ increased the explained variance to 24%. Other predictors were parity, maternal BMI, birth weight, breastfeeding, and the child's head circumference and height at follow-up. These variables, however, only increased the explained variance to 29%. The results suggest that parental education and maternal IQ are major predictors of IQ and should be included routinely in studies of cognitive development. Obstetrical and postnatal factors also predict IQ, but their contribution may be of comparatively limited magnitude.PLoS ONE 11/2013; 8(11):e79200. DOI:10.1371/journal.pone.0079200 · 3.53 Impact Factor
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ABSTRACT: An association between maternal pre-pregnancy BMI and childhood intelligence quotient (IQ) has repeatedly been found but it is unknown if this association is causal or due to confounding caused by genetic or social factors. We used a cohort of 1,783 mothers and their 5-year-old children sampled from the Danish National Birth Cohort. The children participated between 2003 and 2008 in a neuropsychological assessment of cognitive ability including IQ tests taken by both the mother and the child. Linear regression analyses were used to estimate the associations between parental BMI and child IQ adjusted for a comprehensive set of potential confounders. Child IQ was assessed with the Wechsler Primary and Preschool Scales of Intelligence - Revised (WPPSI-R). The crude association between maternal BMI and child IQ showed that BMI was adversely associated with child IQ with a reduction in IQ of -0.40 point for each one unit increase in BMI. This association was attenuated after adjustment for social factors and maternal IQ to a value of -0.27 (-0.50 to -0.03). After mutual adjustment for the father's BMI and all other factors except maternal IQ, the association between paternal BMI and child IQ yielded a regression coefficient of -0.26 (-0.59 to 0.07), which was comparable to that seen for maternal BMI (-0.20 (-0.44 to 0.04)). Although maternal pre-pregnancy BMI was inversely associated with the IQ of her child, the similar association with paternal BMI suggests that it is not a specific pregnancy related adiposity effect.PLoS ONE 04/2014; 9(4):e94498. DOI:10.1371/journal.pone.0094498 · 3.53 Impact Factor