Prevalence of schistosomiasis and its association with anemia among pregnant women: a systematic review and meta-analysis

Abstract

Background: Schistosomiasis is a highly prevalent parasitic disease that can lead to adverse maternal and perinatal outcomes. To our knowledge, there has been no systematic review and meta-analysis of schistosomiasis during pregnancy.

Methods: We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Relevant published studies were searched in international databases (PubMed, Science Direct, Scopus, Web of Science, and Google Scholar), from their inception until May 31, 2020. The retrieved studies were assessed for quality using the Modified Newcastle-Ottawa Scale. OpenMeta Analyst software was used for the statistical analysis.

Results: Thirty-two studies enrolling 21024 pregnant women were included in this meta-analysis. All 32 of these studies were conducted in Africa. Of these studies, 19, 11, and 2 investigated S. mansoni, S. haematobium, and combined S. mansoni and S. haematobium infections, respectively. The pooled prevalence estimate of schistosomiasis during pregnancy was 13.2% (95 CI 11.0-15.4). A random model was used because of high heterogeneity (Q = 99.14; P < 0.001). In subgroup analyses, the pooled prevalence estimate of S. haematobium was significantly higher than the pooled prevalence estimates of S. mansoni [22.5% (95% CI 1.6-43.5) vs 8.7% (95% CI 6.0-11.3, P = 0.016), respectively]. The results of meta-regression analyses showed a non-significant difference in the prevalence of schistosomiasis during pregnancy according to the study sample sizes and year of publication. Only six studies evaluated the association between schistosomiasis during pregnancy and anemia. Schistosomiasis was associated with anemia in these six studies (OR = 3.02, 95% = 1.25‒7.28, P = 0.014).

Conclusion: The present meta-analysis suggests that schistosomiasis during pregnancy is an existing health problem. This meta-analysis also highlights the lack of data on the determinants and outcomes of schistosomiasis during pregnancy. Preventive measures are needed and could be part of antenatal care in areas endemic with schistosomiasis.

Keywords: Pregnancy; Prevalence; Schistosoma haematobium; Schistosoma mansoni.

Fig. 1

Flow diagram showing the number of articles identified in the systematic review and meta-analysis of the prevalence of schistosomiasis during pregnancy.

Fig. 2

Number of studies included from each country.

Fig. 3

Forest plots of ORs with 95% CIs for the meta-analysis of the pooled prevalence of schistosomiasis using a fixed model.

Fig. 4

Forest plots of ORs with 95% CIs for the subgroup analysis of the type of infection in a fixed model in the meta-analysis.

Fig. 5

Funnel plot of the publication bias

Fig. 6

Forest plots of ORs with 95% CIs for the meta-analysis of the association of schistosomiasis with anemia using a fixed model