Stillbirth With Group B Streptococcus Disease Worldwide: Systematic Review and Meta-analyses.

Background. There are an estimated 2.6 million stillbirths each year, many of which are due to infections, especially in low-and middle-income contexts. This paper, the eighth in a series on the burden of group B streptococcal (GBS) disease, aims to estimate the percentage of stillbirths associated with GBS disease. Methods. We conducted systematic literature reviews (PubMed/Medline, Embase, Literatura Latino-Americana e do Caribe em Ciencias da Saude, World Health Organization Library Information System, and Scopus) and sought unpublished data from investigator groups. Studies were included if they reported original data on stillbirths (predominantly >= 28 weeks' gestation or >= 1000 g, with GBS isolated from a sterile site) as a percentage of total stillbirths. We did meta-analyses to derive pooled estimates of the percentage of GBS-associated stillbirths, regionally and worldwide for recent datasets. Results. We included 14 studies from any period, 5 with recent data (after 2000). There were no data from Asia. We estimated that 1% (95% confidence interval [CI], 0-2%) of all stillbirths in developed countries and 4% (95% CI, 2%-6%) in Africa were associated with GBS. Conclusions. GBS is likely an important cause of stillbirth, especially in Africa. However, data are limited in terms of geographic spread, with no data from Asia, and cases worldwide are probably underestimated due to incomplete case ascertainment. More data, using standardized, systematic methods, are critical, particularly from low-and middle-income contexts where the highest burden of stillbirths occurs. These data are essential to inform interventions, such as maternal GBS vaccination.