Toxoplasma gondii infection and spontaneous abortion: A systematic review and meta-analysis

Toxoplasmosis is one of the most common parasitic infections in humans, which is caused by Toxoplasma gondii. It is usually asymptomatic but primary infection in a pregnant woman can cause severe consequences in the fetus such as miscarriage. This study aimed to estimate the global prevalence of T. gondii infection in women with spontaneous abortion. It also evaluates the possible relationship between recent Toxoplasma infection and miscarriage. Five electronic databases were reviewed. We used the random effects model and 95% confidence intervals(CI) to determine the overall prevalence and odds ratio (OR). Heterogeneity was calculated using Cochran's Q test and I² statistic. The included studies were divided into three sub-groups based on antibody class against T. gondii and the existence of parasite DNA. Based on PCR, the pooled random-effects estimates that the prevalence of T. gondii infection in women with abortion was 10% (95% CI 7-14%). The pooled random effect favored a statistically significant increased risk of latent Toxoplasma infection [OR = 1.84; 95% CI: 1.41-2.40, P < 0.001] and recent infection [OR = 3.72; 95% CI: 2.21-6.26, P < 0.001] in women with spontaneous abortions. In recent infections, significant pooled ORs of positive association were observed in women with miscarriage [OR = 4.2; 95% CI: 2.04-8.85; χ2 = 17.2; I² = 42.0%, P = 0.07]. This study demonstrates that recent T. gondii infection is associated with an elevated risk of spontaneous abortion. Further studies concerning all risk factors related to toxoplasmosis, and undertaking confirmatory tests at the time of abortion should be performed to investigate the impact of T. gondii infection and spontaneous abortion.