The review protocol has been registered with the Open Science Framework database (registration number: DOI 10.17605/OSF.IO/BFVPZ) and is being reported in accordance with the reporting guidance provided in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P) statement [29,30,31] (See checklist in Additional file 1). In accordance with scoping review procedure, we will conduct our scoping review as outlined by Arksey [32] and expanded by Peters [33] and The Joanna Briggs Institute [34] using Arksey’s five stages: (1) identifying the research question, (2) identifying relevant studies, (3) selecting studies, (4) charting the data, and (5) collating, summarizing, and reporting the results. We will follow the PRISMA reporting guidelines for scoping reviews to ensure transparency and reproducibility [31]. The evidence will be conducted in a transparent, replicable format in order to identify, characterize, summarize and map existing literature on loneliness in pregnancy, the postpartum period, and new parenthood during the 5 years following the child’s arrival and up to the age of 5.
Eligibility criteria
The Population-Concept-Context (PCC) framework will be used to align the study selection with the research question [34]. To be included in the review, sources of evidence will need to include people who are pregnant, are parents in the postpartum period, or have children under the age of 5. The decision was made to include parents of children under the age of 5, as parenting demands of young children are generally greater in children aged 1 through 5, and this represents a time of rapid transition of life responsibilities and parenting demands. The phenomenon of interest for this scoping review will be the concept of loneliness—the negative feeling associated with the appraisal of one’s social network as somehow deficient, such as in the quantity of social contacts and/or quality of desired types of relationships [19]. This scoping review will consider any research relating to loneliness experienced during pregnancy, the postpartum period, or during the 5 years after the child’s birth, as the aim will be to map the current literature on this topic. We will, however, exclude studies that are primarily interested in loneliness experienced by children of any age, as well as articles where no English-language translation is available.
Information sources and search strategy
The primary source of literature will be a structured search of multiple electronic databases (from inception onwards): MEDLINE (Ovid), EMBASE (embase.com), SCOPUS (scopus.com), Cochrane Library including CENTRAL (Wiley), CINAHL (Ebscohost), PsycINFO (Ebscohost), Dissertations & Theses Global (ProQuest) and Sociological Abstracts (ProQuest) and the Web of Science Core Collection (Clarivate). The secondary source of potentially relevant material will be a search of the grey literature, including the British governmental website, gov.uk, the Jo Cox Commission on Loneliness, the Campaign to End Loneliness, and the British Red Cross’s Action on Loneliness websites. Additional sites may be identified from these sources. The references of included documents will be used to identify any additional sources of evidence. Efforts will be made to contact authors of completed studies, ongoing studies, and in-press or unpublished literature for additional information or relevant material. An information specialist will develop the search strategy for our primary database, MEDLINE (Ovid), then translate for the databases. The search strategies will be peer-reviewed by library colleagues using the Peer Review of Electronic Search Strategies (PRESS) checklist [35]. Strategies will use database subject terms and keywords for loneliness and pregnancy or parenting or parents or mothers or fathers (expecting or child-rearing). A draft search strategy for MEDLINE (Ovid) is provided in Additional file 2.
Selection of sources of evidence
Two reviewers will screen all articles returned by the searches independently. First, titles and abstracts of articles returned from initial searches will be screened based on the eligibility criteria outlined above. Second, full-text articles will be examined in detail and screened for eligibility. Third, references of all considered articles will be hand-searched to identify any relevant publications missed in the search strategy by two reviewers independently. Any disagreement between reviewers will be resolved by discussion to meet a consensus, and a third reviewer will be available to cast a deciding vote in the case that no consensus can be reached between the two reviewers. EndNote version X9 (Clarivate Analytics) will be used to manage citations and remove duplicates. Covidence (Veritas Health Innovation), an online systematic platform, will be used to screen and review search results [36].
Data extraction
REDCap electronic data capture tools hosted at the University of Utah will be used to chart extracted data from our selected articles [37, 38]. Data extraction forms will be piloted initially on a small number of included articles. Each of the included articles will be charted by two reviewers independently. Potential conflicts will be resolved through discussion, and a third reviewer may be included to assist with determining results in the case that conflict is difficult to settle. Authors of primary publications will be contacted for data clarifications or missing outcome data, as necessary. Information of interest will include the following: author(s); year of publication; source origin/country of origin; aims/purpose; study population and sample size; methodology; intervention type and comparator; duration of the intervention; method of measuring outcomes; outcomes/important results; missing data; type of loneliness identified; definition of loneliness used; factors associated with loneliness; factors that protect against loneliness; effects of loneliness on pregnancy outcomes and/or on the child; prevalence of loneliness.
Quality appraisal
In compliance with scoping review methodology [32,33,34], no quality assessment of selected articles will be performed, as our goal is to rapidly map the literature and identify gaps in knowledge.
Data synthesis
The results of the scoping review will be synthesized into a narrative summary in relation to the study objective, research questions, and eligibility criteria (PCC framework). Results will be thematically sorted and arranged according to these criteria. Quantitative data will be summarized as numerical counts and frequencies. We will use tables and graphs to summarize articles, their characteristics, definitions of loneliness, associated factors, and other main findings, based on data extraction criteria. Suggestions for future research based on the study findings will also be summarized.