Sleeping is one of the common but important activities of human being. An adequate sleeping is benefit to health, especially for pregnancy. It is one of the pivotal behaviours which far-reaching affect the health of pregnancy, and the fetal development.

Sleeping and Its Change

Sleep is thought to be essential to clear the brain of metabolic waste products, which accumulate during wakefulness. All tissues produce metabolic waste during the course of normal activity;in the brain, this has particular significance.

The change of the society, at the same time, the mean duration of sleep has changed over the last century: in 1910, it was 9 hours; in 1975, 7.5 hours; and in 2000, 6.9 hours.

Sleep and pregnancy: two challenges to the respiratory system

Sleep is a rest period for most organ systems, including musculoskeletal, gastrointestinal, and cardiovascular. In contrast, sleep challenges the respiratory system in multiple ways. For example, during sleep, the upper airways become narrow and lung volume smaller. These changes are more pronounced during rapid eye movement, when there is decreased muscular tone.

Pregnancy is a physiologic challenge to virtually every organ system (eg, cardiovascular, metabolic, immune), and in particular, the respiratory system. The upper airways narrow due to vascular congestion, mucosal edema, and decreased lung volume. Elevation of the diaphragm, especially in the third trimester, leads to a reduction in functional residual capacity. Thus, the combination of sleep and pregnancy represents a magnified "stress test" to the respiratory system, which can unmask the propensity to develop "sleep-disordered breathing". This term encompasses obstructive sleep apnea, periodic episodes of hypoxia, central apnea, and sleep hypopnea. Although the mechanisms of disease, consequences, and treatment of each of these conditions may differ, the term "sleep-disordered breathing" has been widely used, because respiratory therapy (eg, nasal continuous positive airway pressure [CPAP]) is effective for many of these conditions.

Are sleep disorders during pregnancy associated with gestational diabetes?

In this issue of the American Journal of Obstetrics and Gynecology, Pamidi et al report a systematic review and metaanalysis indicating that maternal sleep-disordered breathing is associated with gestational diabetes (adjusted odds ratio [aOR], 1.86; 95% confidence interval [CI], 1.30–2.45). This association relied on 4 studies in which sleep disorders were diagnosed based on symptoms. In October 2013, Luque-Fernandez et al reported a metaanalysis of sleep-disordered breathing and gestational diabetes based on a total of 9795 pregnant women, and reported that sleep-disordered breathing was associated with a >3-fold risk of gestational diabetes with a pooled body mass index (BMI) aOR of 3.06 (95% CI, 1.89 - 4.96). In the same month, Reutrakul et al reported a study using polysomnography and noted that women with gestational diabetes had a lower total sleep time, a higher apnea hypopnea index, and a greater frequency of obstructive sleep apnea than pregnant women with a normal glucose tolerance test (73% vs 27%, P = .01). This association remained significant after adjustment for prepregnancy BMI (OR, 6.6; 95% CI, 1.15 - 37.96).

Conclusion

Pregnant women have an increased frequency of sleep disturbances and such disorders have been associated with pregnancy complications. Assessment of the quality and quantity of sleep has not been part of routine prenatal care. Whether the association between sleep disturbances and adverse pregnancy outcome is causal needs to be established (using a longitudinal approach, determining a dose response gradient between the severity of the sleep disorder and the subsequent pregnancy complications, and generation of large datasets of observational as well as interventional studies). Practical methods to characterize sleep architecture in pregnancy and define pregnancy-specific screening tools are also needed. The diagnosis and optimal treatment of sleep disorders has potential benefits for: (1) reducing pregnancy complications in the index pregnancy; (2) health of the mother after pregnancy; and (3) short- and long-term consequences for the offspring. Pregnancy may be an ideal time to screen for sleep disturbances and to implement treatment that may have preventive implications and long-term benefits for public health.

The News and information retrieved from: http://www.ajog.org/article/S0002-9378(13)02032-2/ Roberto Romero, MD DMedSci, M. Safwan Badr, MD(2014), American Journal of Obstetrics & Gynecology. Vol.210(1). pp 3-11, 24.