Background
More than 79% of expectant mothers report sleep alterations or sleep disorders during pregnancy and almost 40% report insomnia symptoms. There is growing evidence that sleep quality (SQ) during pregnancy influences maternal health. This review focuses on how SQ during pregnancy relates to maternal health-related quality of life (HRQoL). The review also aims to identify whether this relation varies between pregnancy trimesters. 

Methods
This review was performed according to PRISMA guidelines. Pubmed, Psychinfo, Embase, Cochrane and trial registries were searched up to June 2021. Studies with any design that investigated the relation between SQ and HRQoL in pregnant women, published in English, and peer-reviewed, were included. Two independent reviewers screened titles, abstracts and full texts, and extracted data. The quality of the studies was evaluated using the Newcastle-Ottawa Scale.

Results
313 Papers were identified initially, of which 10 met the inclusion criteria. Data included 7330 participants. The studies had cohort (n=1) or cross-sectional designs (n=9).  Nine studies reported SQ subjectively by self-report questionnaires. Actigraphic data was available from two studies. HRQoL was assessed by validated questionnaires in all studies. Nine articles found that poor SQ and/or insomnia were related to a lower overall HRQoL during pregnancy. Effect sizes were low to medium. This relation was reported most during the third trimester. Sleep disturbances and subjective low SQ seemed to be related consistently to lower HRQoL.

Conclusion
Despite the scarcity of studies available, this systematic review found evidence that low SQ is related to low HRQoL during pregnancy. An indication was found that the relation between SQ and HRQoL during the second trimester might be less prominent. Further studies with both subjective and objective sleep measures are needed to shed light on the causality and its direction of this relationship, preferably in intervention studies that try to improve SQ.