The Medical Implications of Insomnia During Pregnancy

Insomnia is a very common sleep disorder characterized by delayed sleep initiation, short sleep duration, and poor sleep quality that can result in decreased work productivity, maladapted socio-emotional interactions, derangement in cardiometabolic and immunologic function, higher rates of medication and substance abuse, as well as the increased prevalence of mood disorder and suicide.

Insomnia occurs far more frequently in females and complicates the unique physiological and social-emotional changes associated with being pregnant. Insomnia has been reported in at least one-third of all pregnant women and predominates in the second and third trimesters. Pregnant women awaken in the night frequently, have decreased sleep depth, progesterone-mediated nasal congestion, frequent need to urinate, and restless legs syndrome.

Needless to say, many studies have documented poor neonatal and maternal outcomes in pregnancies affected by sleep disorders. Reduced fetal growth, fetal growth restriction, preterm birth, stillbirth, and maternal morbidities such as preeclampsia, cardiomyopathy, and maternal mortality are more common. Insomnia during pregnancy is associated with poor maternal mental health, such as depression, anxiety, and suicidal ideation.

A recent publication reported on the prevalence of insomnia among pregnant patients between 2006 to 2017. The study examined the interplay among insomnia, maternal comorbid conditions, and severe maternal morbidity. The study authors' data were obtained from almost 47 million pregnancies that occurred in more than 4500 hospitals in 48 states.

Their results showed that the rate of insomnia increased with maternal age. In addition, there was a strong association between insomnia and nearly all obstetric comorbidities. Most importantly, the study discovered that the diagnosis of insomnia is an independent predictor of severe maternal morbidity at delivery.

The study confirmed that the incidence of insomnia associated with pregnancy is increasing most likely due to a trend that pregnant women are generally older with more prevalent obesity and other comorbid conditions. Overall, insomnia during pregnancy increased the likelihood of co-existing major mental health disorders. The study also reported an increased association of sleep disturbances with maternal preeclampsia and gestational hypertension.

The rate of insomnia during pregnancy did not differ significantly among income levels. Overall, the study discovered that pregnant women with insomnia have a higher cumulative incidence of obstetric comorbid conditions. Many of the conditions noted in the study, such as neuromuscular disease, asthma, obesity, and substance use disorder, may cause or exacerbate insomnia for reasons directly related to physical complications. In addition, insomnia can impair immune function and increase blood levels of inflammatory proteins. However, due to the very large sampling size, the authors were able to focus solely on the impact of insomnia. After mathematically adjusting for typical physical comorbidities, the study discovered that there remained a 24 percent increase in the likelihood of severe maternal morbidities due to insomnia.

This is the largest study to date that examined how a diagnosis of insomnia during pregnancy is associated with unexpected adverse maternal events.