Background: About 2·1 million pregnant women have active syphilis every year. Without screening and treatment, 69% of these women will have an adverse outcome of pregnancy. The objectives of this study were to review the literature systematically to determine the effectiveness of screening interventions to prevent congenital syphilis and other adverse pregnancy outcomes.

Methods: We searched four electronic databases and selected studies to examine evidence for effectiveness of interventions on three outcomes: increased uptake of syphilis testing, increased treatment rates, and reduction in adverse pregnancy outcomes. We used fixed effects meta-analysis to estimate pooled relative risks if no or little evidence of heterogeneity between trials existed.

Findings: Ten studies met the inclusion criteria, including two randomised trials. Only two studies aimed to encourage women to seek care earlier in pregnancy. Nine studies included decentralisation of screening and treatment. The effects of the interventions on uptake of testing for antenatal syphilis and receiving at least one dose of penicillin were variable and could not be combined statistically. Study interventions were associated with a reduction in perinatal death (pooled risk ratio [RR] from three studies 0·46, 95% CI 0·26-0·82) and stillbirth (pooled RR from three studies 0·42, 95% CI 0·19-0·93). The incidence of congenital syphilis was reduced in all four studies that measured this outcome with heterogeneous results.

Interpretation: Interventions to improve the coverage and effect of screening programmes for antenatal syphilis could reduce the syphilis-attributable incidence of stillbirth and perinatal death by 50%. The resources required to roll out antenatal screening programmes would be a worthwhile investment for reduction of adverse pregnancy outcomes and improvement of neonatal and child survival.

Funding: None.