Why this study? We know sleep apnoea during pregnancy contributes to complications like gestational hypertension and diabetes for mothers-to-be, but what we know much less about how pauses in breathing overnight affect the baby and its development.
What we did: We combined and analysed data from birth and hospital records, and school standardised tests to examine how women's sleep apnoea during pregnancy affects the health and development in their child. The study included all women who gave birth in New South Wales in 2002 to 2012.
What we found: Hospital admissions were more common in the children of women with sleep apnoea. This was partly because these children were more likely to have sleep apnoea themselves, but even when we excluded these children, hospital admissions were still elevated compared to the children of women who didn’t have sleep apnoea during pregnancy. Unfortunately, we did not have enough information to understand why the kids were more likely to be admitted to hospital and this is a question for future studies.
The good news is that maternal sleep apnoea does not seem to affect the children over the longer term. We found that developmental status in the first year of school, and reading and numeracy test results in the third year of school were unaffected by maternal sleep apnoea. In all of our analyses, we controlled for other important factors such as socioeconomic status and preterm birth, so we know they are not responsible for the results.
What does this mean? Babies whose mothers had sleep apnoea during pregnancy have poorer health, particularly in the first year of life. Ours is just one study, and it needs to be repeated in other populations, but it is the first to look at long-term effect of maternal sleep apnoea on the child.
2. Share a PubMed or DOI link to article
3. Do you have any ideas to expand upon this research? Are you looking for collaborators?
The key limitation of this study is that it is a retrospective study and relies on data that was not designed for research so there are quite a few unknowns that I would like to address in future studies.
First, we do not know the severity of the sleep apnoea involved. Second, we do not know if the women with sleep apnoea were treated, how they were treated, and if they adhered to treatment. Knowing these, we could show a dose-response relationship between sleep apnoea severity/treatment and the outcomes which would provide stronger evidence that the sleep apnoea is responsible for poorer child health. Another unknown is the extent to which sleep apnoea only develops in pregnancy because of weight gain and if it resolves soon after giving birth.
I would be interested in conducting a prospective cohort study of pregnant women with clinical researchers with an interest in maternal-fetal medicine or paediatrics. I would aim to formally screen and treat pregnant women for sleep-disordered breathing and follow them up over the course of pregnancy to see if treatment for sleep apnoea does indeed reduce adverse outcomes for both mother and baby. This would provide information on the severity of sleep apnoea, its trajectory over the course of pregnancy, as well as whether its severity and treatment contributes to poor maternal and fetal health. This would include reducing the rate of complications like pregnancy hypertension and diabetes, and delivery outcomes such as preterm birth, as well as improving child health in the first year of life.
Longer term childhood outcomes would be much harder to explore in a prospective cohort given that we would have to wait for the children to grow up, but it is possible to combine a pregnancy cohort with a data linkage study like the one we have published so that no continuous follow-up of the children are necessary.
Lastly, if there are population-based datasets in other states and countries that can be used to repilcate our study, I would be keen to collaborate and to see if the data reveal similar results.
Sun is an epidemiologist at the Charles Perkins Centre, University of Sydney. Her particular research interests are in the impact of sleep and sleep disorders on public health.
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