**2.4.2 Activation of neuroendocrine pathways**

Activation of the sympathetic Nervous System (SNS) leads to the release of adrenal hormones (catecholamines), which can have an effect on sleep (Guggisberg, 2007). Furthermore, the production of catecholamines may stimulate the production of inflammatory cytokines. Inflammatory processes are modulated by numerous feedback and feed forward mechanisms. The Hypothalamic-pituitary-adrenal axis also regulates inflammatory processes via cortisol secretion, which is secreted in a diurnal manner following the sleep-wake cycle. Cortisol can suppress the production of pro-inflammatory cytokines and, as part of the negative feedback mechanism designed to prevent uncontrolled inflammation, pro-inflammatory cytokines stimulate the HPA axis to produce cortisol. However, as in the case of SDB and the resulting hypoxia, plasma cortisol is chronically raised (Meerlo et al, 2000). Prolonged cortisol secretion leads the glucocorticoid receptors becoming desensitised and results in a decrease in the protective effects of cortisol against inflammation (Sapolsky et al, 2000). Disrupted sleep can lead to mild stimulation of the HPA axis and increased inflammation, thus providing another mechanism whereby disrupted sleep in pregnancy may lead to dysregulation of normal homeostatic processes and potentially lead to adverse pregnancy outcomes (Okun et al, 2009).

#### **2.4.3 Insulin resistance**

Accumulating evidence suggests that both poor sleep quantity and quality are associated with impaired glucose tolerance and diabetes (Cappuccio et al, 2010a). Until recently little has been known about the effect of poor sleep during pregnancy on glucose tolerance and gestational diabetes. Qui et al interviewed a large cohort of 1,290 women during early pregnancy. They collected information regarding sleep duration and snoring during pregnancy. They obtained information on gestational diabetes mellitus (GDM) from the screening and test results in their medical records. They found that those women who slept 4 hours or less had a greater risk of GDM than those sleeping 9 hours per night. Furthermore they observed that whilst the increased relative risk was 3.23 (95% CI 0.34-

Sleep and Pregnancy: Sleep Deprivation,

**2.6 Implications for public health** 

environment can improve sleep for new mothers.

duration or quality.

**3. Conclusion** 

Sleep Disturbed Breathing and Sleep Disorders in Pregnancy 13

In the general population sleep duration has been declining. Women now occupy an increasingly prominent position in the workplace but often they do so without any reduction in their home responsibilities. Consequently sleep needs are often of low priority. Preterm birth is a major public health priority and is a common adverse outcome in pregnancy. Sleep quantity and quality are not only important determinants of maternal and foetal health but are also important for general health and need to be particularly addressed in the post-partum period where sleep disruption is likely to be very common. There is also some evidence to suggest that the effects of sleep deprivation may be greater in women than in men. Despite this, the majority of studies undertaken are in men and there is now a clear

There is also a paucity of studies evaluating sleep disturbances in the post-partum period and research is required to look at the effects of sleep deprivation on both maternal and paternal functioning and the effect on maternal-infant interaction. Factors such as the type of delivery, the type of infant feeding, return-to-work time and infant temperament may be important, along with the degree of support from the father or other family members. A recent randomised trial set out to investigate if modification to the bedroom environment could improve the sleep of new parents (Lee & Gay, 2011). They evaluated a modified sleep hygiene intervention for new parents (infant proximity, noise masking, and dim lighting) in anticipation of night-time infant care in two samples of new mothers of different socioeconomic status. They were randomized to the experimental intervention or attention control, and sleep was assessed in late pregnancy and first 3 months postpartum using actigraphy and the General Sleep Disturbance Scale. The investigators observed that whilst the sleep hygiene strategies evaluated did not benefit the more socioeconomically advantaged women or their partners they did improve postpartum sleep among the less advantaged women suggesting that simple inexpensive changes to the bedroom

Further studies are required fully to investigate the effects of smoking on sleep and associated adverse pregnancy outcomes but meanwhile educational programmes could be used to educate women on the possible harmful effects. Research to determine if other health behaviours could have beneficial effects on sleep in pregnant women is also required. For example, physical activity is recommended to pregnant women for health benefits but as yet there are insufficient studies to determine if this has any effect on improving sleep

A lack of sleep is known to affect both our physical and mental health. The few studies that have investigated sleep in pregnancy have found both an increase in total sleep time and an increase in daytime sleepiness in the first trimester whereas the third trimester appears to be associated with a decrease in sleep time and an increase in the number of awakenings. Sleep has an important impact on maternal and foetal health. It has been associated with an increased duration and pain perception in labour, with a higher rate of caesarean delivery and with preterm labour. Some pregnant women develop sleep disorders such as RLS or OSA or insomnia and others develop postpartum depression. Longitudinal studies are required to fully evaluate the effect of sleep deprivation on maternal and foetal outcome.

need for more, large, multicentre, prospective studies to be performed in women.

30.41) for lean women (<25 kg/m2) this was increased to 9.83 (95% CI 1.12-86.32) for overweight women (> or = 25 kg/m2). Snoring was also associated with a 1.86-fold increased risk of GDM and the risk of GDM was 6.9 xs higher in overweight than lean women (Qiu et al, 2010). These findings are consistent with data in non-pregnant women and warrant further investigation to determine the effect on pregnancy outcome.

#### **2.4.4 Passive smoking**

In Japan, two surveys were conducted to determine if passive smoking might have any effect on the sleep disturbances observed in pregnant women. 16,396 pregnant women were surveyed in 2002 and 19,386 in 2006. This is particularly important as 80% of passive environmental smoking comes from the spouse and in Japan there is a very high smoking rate amongst men (53%). The results indicated that passive smoking is independently associated with increased sleep disturbances during pregnancy. They observed that pregnant woman who were exposed to passive smoking were likely to suffer from difficulty in initiating sleep, short sleep, and snoring; those women who smoked suffered from the same disturbances and also reported early morning awakenings and excessive daytime sleepiness (Ohida et al, 2007). The authors suggest that some of the negative health outcomes observed in pregnant women may be mediated by the effect of active and passive smoking on sleep.

#### **2.5 Diagnosis and management of sleep disorders in pregnancy**

There are many different ways in which sleep data can be collected, the gold standard, however, is to measure sleep using polysomnography (PSG) as this provides an objective assessment of the sleep-wake cycle over the entire sleep period (Baker et al, 1999). Much of the data regarding sleep in pregnancy is limited to self-administered questionnaires and to diaries: very few recent studies have used PSG. However, it is recognised that undertaking multiple sleep studies at different time points during pregnancy is difficult. Despite this there is evidence to suggest that sleep disorders in pregnancy can in certain individuals have adverse outcomes for the mother or baby and therefore it would be useful to develop a screening tool that could be administered quickly by health professionals during routine pregnancy consultations. A simple and cost-effective alternative to PSG is to use actigraphy and sleep diaries. There are now many wrist-watch style actigraphs available. They are activated by movement and can differentiate when a person is awake or asleep, many also now have light monitors incorporated in them as well. They are useful in identifying night time awakenings and for determining their subsequent duration. When used in conjunction with self-recorded sleep diaries, actigraphs can help to establish a very detailed sleep pattern. Questionnaires administered to a bed partner can also help to establish a diagnosis of sleep disordered breathing. OSA is a common but often unrecognised condition in women of childbearing age. The likelihood is increased however in women with a past or current history of polycystic ovary syndrome, depression, hypertension, diabetes, hypothyroidism, metabolic syndrome, obesity (Champagne et al, 2010). The diagnostic test of choice would be a PSG, and referral to a sleep specialist to confirm and treat primary sleep disorders may be required. Further research is also required to establish if the management thresholds for treatment of OSA in non-pregnant women are applicable to pregnant women.

Pharmacological treatment of sleep disorders in pregnancy needs to be viewed with caution, given the potential for harm to the foetus. Similar caution needs to extend to women who are breastfeeding.

### **2.6 Implications for public health**

12 Sleep Disorders

30.41) for lean women (<25 kg/m2) this was increased to 9.83 (95% CI 1.12-86.32) for overweight women (> or = 25 kg/m2). Snoring was also associated with a 1.86-fold increased risk of GDM and the risk of GDM was 6.9 xs higher in overweight than lean women (Qiu et al, 2010). These findings are consistent with data in non-pregnant women

In Japan, two surveys were conducted to determine if passive smoking might have any effect on the sleep disturbances observed in pregnant women. 16,396 pregnant women were surveyed in 2002 and 19,386 in 2006. This is particularly important as 80% of passive environmental smoking comes from the spouse and in Japan there is a very high smoking rate amongst men (53%). The results indicated that passive smoking is independently associated with increased sleep disturbances during pregnancy. They observed that pregnant woman who were exposed to passive smoking were likely to suffer from difficulty in initiating sleep, short sleep, and snoring; those women who smoked suffered from the same disturbances and also reported early morning awakenings and excessive daytime sleepiness (Ohida et al, 2007). The authors suggest that some of the negative health outcomes observed in pregnant women

There are many different ways in which sleep data can be collected, the gold standard, however, is to measure sleep using polysomnography (PSG) as this provides an objective assessment of the sleep-wake cycle over the entire sleep period (Baker et al, 1999). Much of the data regarding sleep in pregnancy is limited to self-administered questionnaires and to diaries: very few recent studies have used PSG. However, it is recognised that undertaking multiple sleep studies at different time points during pregnancy is difficult. Despite this there is evidence to suggest that sleep disorders in pregnancy can in certain individuals have adverse outcomes for the mother or baby and therefore it would be useful to develop a screening tool that could be administered quickly by health professionals during routine pregnancy consultations. A simple and cost-effective alternative to PSG is to use actigraphy and sleep diaries. There are now many wrist-watch style actigraphs available. They are activated by movement and can differentiate when a person is awake or asleep, many also now have light monitors incorporated in them as well. They are useful in identifying night time awakenings and for determining their subsequent duration. When used in conjunction with self-recorded sleep diaries, actigraphs can help to establish a very detailed sleep pattern. Questionnaires administered to a bed partner can also help to establish a diagnosis of sleep disordered breathing. OSA is a common but often unrecognised condition in women of childbearing age. The likelihood is increased however in women with a past or current history of polycystic ovary syndrome, depression, hypertension, diabetes, hypothyroidism, metabolic syndrome, obesity (Champagne et al, 2010). The diagnostic test of choice would be a PSG, and referral to a sleep specialist to confirm and treat primary sleep disorders may be required. Further research is also required to establish if the management thresholds for treatment of

Pharmacological treatment of sleep disorders in pregnancy needs to be viewed with caution, given the potential for harm to the foetus. Similar caution needs to extend to women who

and warrant further investigation to determine the effect on pregnancy outcome.

may be mediated by the effect of active and passive smoking on sleep.

**2.5 Diagnosis and management of sleep disorders in pregnancy** 

OSA in non-pregnant women are applicable to pregnant women.

are breastfeeding.

**2.4.4 Passive smoking** 

In the general population sleep duration has been declining. Women now occupy an increasingly prominent position in the workplace but often they do so without any reduction in their home responsibilities. Consequently sleep needs are often of low priority. Preterm birth is a major public health priority and is a common adverse outcome in pregnancy. Sleep quantity and quality are not only important determinants of maternal and foetal health but are also important for general health and need to be particularly addressed in the post-partum period where sleep disruption is likely to be very common. There is also some evidence to suggest that the effects of sleep deprivation may be greater in women than in men. Despite this, the majority of studies undertaken are in men and there is now a clear need for more, large, multicentre, prospective studies to be performed in women.

There is also a paucity of studies evaluating sleep disturbances in the post-partum period and research is required to look at the effects of sleep deprivation on both maternal and paternal functioning and the effect on maternal-infant interaction. Factors such as the type of delivery, the type of infant feeding, return-to-work time and infant temperament may be important, along with the degree of support from the father or other family members. A recent randomised trial set out to investigate if modification to the bedroom environment could improve the sleep of new parents (Lee & Gay, 2011). They evaluated a modified sleep hygiene intervention for new parents (infant proximity, noise masking, and dim lighting) in anticipation of night-time infant care in two samples of new mothers of different socioeconomic status. They were randomized to the experimental intervention or attention control, and sleep was assessed in late pregnancy and first 3 months postpartum using actigraphy and the General Sleep Disturbance Scale. The investigators observed that whilst the sleep hygiene strategies evaluated did not benefit the more socioeconomically advantaged women or their partners they did improve postpartum sleep among the less advantaged women suggesting that simple inexpensive changes to the bedroom environment can improve sleep for new mothers.

Further studies are required fully to investigate the effects of smoking on sleep and associated adverse pregnancy outcomes but meanwhile educational programmes could be used to educate women on the possible harmful effects. Research to determine if other health behaviours could have beneficial effects on sleep in pregnant women is also required. For example, physical activity is recommended to pregnant women for health benefits but as yet there are insufficient studies to determine if this has any effect on improving sleep duration or quality.

### **3. Conclusion**

A lack of sleep is known to affect both our physical and mental health. The few studies that have investigated sleep in pregnancy have found both an increase in total sleep time and an increase in daytime sleepiness in the first trimester whereas the third trimester appears to be associated with a decrease in sleep time and an increase in the number of awakenings. Sleep has an important impact on maternal and foetal health. It has been associated with an increased duration and pain perception in labour, with a higher rate of caesarean delivery and with preterm labour. Some pregnant women develop sleep disorders such as RLS or OSA or insomnia and others develop postpartum depression. Longitudinal studies are required to fully evaluate the effect of sleep deprivation on maternal and foetal outcome.

Sleep and Pregnancy: Sleep Deprivation,

Gynecol, Vol.88, pp. 797-800.

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Sleep Disturbed Breathing and Sleep Disorders in Pregnancy 15

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Better methods to measure sleep disturbances in pregnancy are required along with evaluation of the underlying cause so that appropriate and effect treatment can be administered. Particular attention needs to be given to women who develop leg complaints, who are overweight or become obese during pregnancy or develop conditions such as diabetes or PIH.
