Search

Twin studies can help us understand the relative contributions of genes and environment to phenotypic trait variation, including attentional and brain activation measures. In terms of applying methodologies such as electroencephalography (EEG) and eye tracking, which are key methods in developmental neuroscience, infant twin studies are almost nonexistent. Here, we describe the Babytwins Study Sweden (BATSS), a multi-method longitudinal twin study of 177 MZ and 134 DZ twin pairs (i.e., 622 individual infants) covering the 5-36 month time period. The study includes EEG, eye tracking and genetics, together with more traditional measures based on in-person testing, direct observation and questionnaires. The results show that interest in participation in research among twin parents is high, despite the comprehensive protocol. DNA analysis from saliva samples was possible in virtually all participants, allowing for both zygosity confirmation and polygenic score analyses. Combining a longitudinal twin design with advanced technologies in developmental cognitive neuroscience and genomics, BATSS represents a new approach in infancy research, which we hope to have impact across multiple disciplines in the coming years. [ABSTRACT FROM AUTHOR]

To date, several studies have investigated the intergenerational effect of preterm and small-for-gestational-age (SGA) births. However, most studies excluded both twin mothers and twin offspring from the analyses. Thus, the objective of this study was to investigate the intergenerational effect of preterm birth and SGA births among twins and singletons. A prospective population-based register study of mother–firstborn offspring pairs recorded in the Swedish Medical Birth Register was performed. The study included 4,073 twins and 264,794 singletons born from 1973–1983 and their firstborns born from 1986–2009. Preterm birth was defined as birth at <37 weeks of gestation, and SGA as birth weight <2 standard deviations of the Swedish standard. Logistic regressions were performed to estimate the intergenerational effect of each birth characteristic. Adjustments were made for maternal grandmothers’ and mothers’ socio-demographic factors, in addition to maternal birth characteristics. Among mothers born as singletons, being born preterm was associated with an increased risk of delivering a preterm child (adjusted odds ratio (OR) 1.39, 95% Confidence Interval (CI) = 1.29–1.50), while being born SGA increased the likelihood of having an SGA child (adjusted OR 3.04, 95% CI = 2.80–3.30) as well as a preterm child (adjusted OR 1.30, 95% CI = 1.20–1.40). In twin mothers, the corresponding ORs tended to be lower, and the only statistically significant association was between an SGA mother and an SGA child (adjusted OR 2.15, 95% CI = 1.40–3.31). A statistically significant interaction between twinning and mother's size for gestational age was identified in a multivariate linear regression analysis, indicating that singleton mothers born SGA were associated with a lower birth weight compared with mothers not born SGA. Preterm birth and SGA appear to be transferred from one generation to the next, although not always reaching statistical significance. These effects seem to be less evident in mothers born as twins compared with those born as singletons. [ABSTRACT FROM PUBLISHER]