The influence of pre-pregnancy weight and weight changes on pregnancy complications and child growth and development

Abstract

Background and aims: Pre-pregnancy obesity (body mass index [BMI] ≥ 30 kg/m 2 ) and pregnancy complications such as gestational diabetes mellitus (GDM) and hypertensive disorders of pregnancy (HDP) are major and increasing global public health concerns because of a number of consequences to women and their babies. While the associations of pre-pregnancy obesity and GDM and HDP are well established, little is known about the relationship between pre-pregnancy weight change and GDM and HDP risk. Growing evidence also implicates pre-pregnancy obesity and pregnancy complications with offspring childhood growth and development, although the findings are inconclusive, and associations of preconception BMI trajectory and child outcomes have been rarely investigated. This thesis examines the associations between pre-pregnancy weight characteristics, GDM and HDP and offspring childhood growth and development. Methods: Several data sources and analysis approaches were employed across the papers included in the thesis. First, literature searches were performed in CINAHL, EMBASE, PSYCINFO, PUBMED and SCOPUS for systematic reviews on 1) the association of pre-pregnancy obesity and offspring childhood physical and cognitive development, and 2) the association of diabetes during pregnancy and childhood cognitive development. Second, self-reported data from the 1973-78 cohort (aged 18-23 years at the first survey in 1996) of the Australian Longitudinal Study on Women's Health (ALSWH) were used to examine the associations between adult pre-pregnancy weight change and GDM (n = 5,242) and HDP (n = 4,813) risk. Third, data from the 1973-78 cohort of the ALSWH, Mothers and their Children's Health (MatCH) study and linked data from the Australian Early Development Census (AEDC) were used to evaluate the associations of 1)preconception BMI trajectories, GDM and HDP and offspring childhood physical and cognitive development (n = 771), and 2) preconception BMI trajectories and offspring childhood BMI (n = 2,733), and 3) to quantify the mediation role of offspring's birthweight between the association of pre-pregnancy BMI and childhood anthropometrics (BMI-for-age, height-for-age, weight-for-age and weight-for-height) (n = 1,618). In addition to descriptive statistics, multinomial logistic regression, generalised estimating equations, g-computation and latent class growth modelling were used for analyses. Results:A total of 17 articles were eligible for the systematic review on pre-pregnancy obesity and offspring childhood physical and cognitive development. A large proportion of studies supported the adverse association between pre-pregnancy obesity and childhood cognitive development. A few studies also demonstrated a negative association between pre-pregnancy obesity and the gross