A study conducted by researchers from the University of California, San Francisco (UCSF) has credited sleep disorders, such as apnoea and insomnia, in pregnant mothers to be the cause of premature births. Premature births are the main cause of death for children under the age of five, worldwide.

Every year, more than 15 million babies are born prematurely – with about 1 million succumbing to death – while the others are left with birth-related complications like hearing impairment, learning disabilities, cerebral palsy and more.

“It is normal to experience sleep changes during pregnancy – often due to discomfort, pain or frequent trips to the bathroom,” explained Jennifer Felder, PhD, a postdoctoral fellow in the UCSF Department of Psychiatry and the lead author of the study.

“The current study focused on more impairing sleep problems that were severe enough to result in a sleep disorder diagnosis.”

Studying sleep

Full term babies were those born between 37 – 40 weeks of gestation. The study focused on premature births at 34 – 36 weeks of gestation and also some extremely premature births earlier than 34 weeks. The study has acquired more than 3 million birth data, between 2007 and 2012, in California.

The data consisted of notes of the mother and baby taken during visits and delivery – out of which, slightly more than 2,000 mothers were diagnosed by doctors to have sleep disorders such as insomnia and apnoea.

Due to the large number of data, the researchers were able to draw parallels. The researchers used a case-control design; 2,172 women with sleep disorder diagnosis were matched with 2,172 women without sleep disorder diagnosis; but were otherwise similar in other areas and risk for premature delivery.

The result has singled out the effect of sleep disorder from the other contributing factors of premature births. Pregnant women with insomnia had a 30% raised chance of delivering prematurely while pregnant women with sleep apnoea had a chance of premature delivery raised by 40%.

In addition, 5% of women with sleep disorders delivered earlier than 34 weeks compared to 3% of women who didn’t have sleep disorders.

Sleeping saves lives

Although the study is confidently attributing sleep disorder to premature births, Felder said that sleep disorder is unlikely to be the direct cause of early arrivals. It could however, trigger other processes like inflammation as suggested in earlier studies that would lead to premature births.

“More work is urgently needed to test whether this is a causal relationship, identify biological mechanisms, and test the efficacy of interventions for sleep disorders during pregnancy and the effect on premature birth," she added.

Felder and her team are on to a new study, to find out if cognitive behavioural therapy can help women with insomnia and ultimately reduce premature births. This therapy has been shown to be effective across the general population and does not require medication, which most pregnant women do not prefer.

It is unclear if getting enough sleep before or during the pregnancy will tackle the premature birth issue. However, Dr Amos Grunebaum, director of obstetrics at New York-Presbyterian Hospital stated that starting pregnancy at an ideal weight will make sleep disorders more unlikely. In addition, expectant mothers should allow enough time for sleep and make it a priority, which could save her baby’s life. MIMS

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