What are the links between maternal chronic disease and long-term outcomes that appear in offspring?

A group of teenagers walking to class

Data access has been approved for a longitudinal study to examine the associations between maternal chronic disease and long-term outcomes that appear in childhood, adolescence or in early adulthood in offspring. The study, one of the largest of its kind, will follow one million singleton live births for up to 26 years. The results will be used to promote health in pregnant women living with chronic illness, and to minimize the incidence of adverse outcomes for mothers and their children.

The project, funded by Canadian Institutes of Health Research (CIHR), is jointly led by Neda Razaz, Assistant Professor at the Karolinska Institutet, Sweden, and Professor K S Joseph at the University of British Columbia’s Department of Obstetrics & Gynaecology and the School of Population and Public Health. The collaborative project will investigate whether the results are similar for children born in Sweden compared with those born in British Columbia (BC).

Maternal chronic illness is associated with pregnancy complications and neonatal complications, which may in turn influence long-term adverse outcomes in offspring. Several explanations have been offered for the increased prevalence of chronic health conditions in the child-bearing population in Canada and other high-income countries. These include: an increasing proportion of women giving birth at older ages; rising levels of obesity and related health issues; refugee and immigrant mothers with suboptimal health status; improved survival and quality of life among women with chronic disease due to improvements in medicine and surgery; and rising rates of fertility among women with subfertility and infertility.

“Although there is reason to suspect and hypothesize a long-term morbidity effect of maternal chronic disease, the chronic diseases most likely to be responsible for such effects (e.g. diabetes, hypertension, lung, heart and autoimmune diseases), the magnitude of such effects and the pathways connecting maternal chronic illness and adverse outcomes are unknown,” says Professor Razaz. “There is a paucity of information on how prenatal exposure to maternal chronic illness influences offspring long-term morbidity.”

The study aims to investigate this causal sequence by firstly examining and quantifying the associations between maternal chronic illness and long-term morbidity in offspring. Secondly, the project will conduct formal mediation analyses of the association between maternal chronic illness and adverse outcomes.

“This will enable us to identify the direct and indirect pathways (through pregnancy and obstetric complications, comorbidity, preterm birth, fetal growth and neonatal complications) between maternal chronic disease and adverse outcomes using longitudinal cohorts from BC,” explains Professor Joseph.

Specifically, the project will investigate the risk of neuro-psychiatric developmental disorders and physical diseases in relation to; chronic illnesses in the mother (e.g., hypertension, diabetes, cardiovascular disease); pregnancy complications, delivery and newborn period; and interventions during pregnancy and newborn period.

Through mediation analyses the project will investigate: whether a possible relationship between premature birth and long-term risks can be explained by illnesses in the newborn period; and whether a possible link between chronic illness and long-term risks can be explained by complications during pregnancy or the newborn period.

For the study, PopData will link six data sets from the BC Ministry of Health with data from the BC Ministry of Education, Statistics Canada and the Human Early Learning Partnership’s Early Development Instrument.