Identifying, synthesising and appraising existing evidence relating to myalgic encephalomyelitis/chronic fatigue syndrome and pregnancy: a mixed-methods systematic review.

Objectives: To identify, synthesise and appraise evidence relating to myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and pregnancy.

Design: Mixed-methods systematic review, using convergent segregated design.

Data Sources: MEDLINE, EMBASE, Scopus, PsycINFO, CINAHL, MedRxiv, PROSPERO and grey literature sources through 6 August 2023.

Eligibility Criteria: We included original research studies, expert opinion and grey literature reporting on ME/CFS and pregnancy/post partum (up to 2 years), risk of pregnancy outcomes with ME/CFS or experiences during pregnancy for mother, partner or health and social care professionals following ME/CFS during pregnancy, all where the evidence was relevant to a confirmed ME/CFS diagnosis prior to pregnancy.

Data Extraction And Synthesis: Three independent reviewers completed all screening, data extraction and quality assessment. Risk of bias was assessed using the mixed-methods appraisal tool V.2018. Qualitative and quantitative literature was analysed separately using thematic and descriptive syntheses. Findings were integrated through configuration.

Results: Searches identified 3675 articles, 16 met the inclusion criteria: 4 quantitative (1 grey), 11 qualitative (9 grey) and 1 grey mixed-methods study. Of the four quantitative studies that reported on ME/CFS severity during pregnancy, two suggested pregnancy negatively impacted on ME/CFS, one found most women had no change in ME/CFS symptoms and one found ME/CFS improved; this difference in symptom severity across studies was supported by the qualitative evidence. The qualitative literature also highlighted the importance of individualised care throughout pregnancy and birth, and the need for additional support during family planning, pregnancy and with childcare. Only one quantitative study reported on pregnancy outcomes, finding decreased vaginal births and higher rates of spontaneous abortions and developmental and learning delays associated with pregnancies in those with ME/CFS.

Conclusions: Current evidence on ME/CFS in pregnancy is limited and findings inconclusive. More high-quality research is urgently needed to support the development of evidence-based guidelines on ME/CFS and pregnancy.