Background: Partner infection is a significant factor in preventing mother-to-child syphilis transmission. We compared pregnancy outcomes between syphilis discordant and syphilis concordant couples.
Methods: We conducted a retrospective study among 3076 syphilis-positive women who received syphilis screening together with their partners during pregnancy. Multivariate analysis was used to explore risks for abnormal outcomes in objects correcting for the major covariate factors. Adjusted odds ratios (OR) and 95% confidence intervals (CI) were estimated to compare pregnancy outcomes between syphilis concordant and syphilis discordant couples.
Results: Overall, 657 of the 3076 women were diagnosed with gestational syphilis and had a syphilis-positive partner, giving a partner concordance prevalence of 21.36%. Women in concordant couples were more likely to have higher parity, more children, late antenatal care and syphilis screening, a lower proportion of latent syphilis, and elevated serologic titers than women in discordant couples (P < 0.01 for all). Totally, 10.08% of women had adverse pregnancy outcomes. Multivariate analysis showed partners' syphilis infection (ORadj = 1.44, 95% CI: 1.10-1.89), untreated pregnancy syphilis (ORadj = 1.67, 95% CI: 1.15-2.43), and higher maternal serum titers (> 1:8) (ORadj = 1.53, 95% CI: 1.17-2.00) increased the risks of adverse pregnancy outcomes. Concordance was associated with increased risk for stillbirth (ORadj = 2.86, 95%CI:1.36-6.00), preterm birth (PTB) (ORadj = 1.38,95%CI:1.02-1.87) and low birth weight (LBW) (ORadj = 1.55, 95%CI:1.13-2.11) compared with discordance. Even among treated women, concordance was associated with increased risk for stillbirth (ORadj = 3.26, 95%CI:1.45-7.31) and LBW (ORadj = 1.52, 95%CI:1.08-2.14). Among women with one treatment course, the risks for PTB(ORadj = 1.81, 95%CI:1.14-2.88) and LBW(ORadj = 2.08, 95%CI:1.28-3.38)were also higher among concordant couples than discordant couples. Nevertheless, there were no significant differences between concordant and discordant couples in risks of stillbirth (ORadj = 2.64, 95% CI: 0.98-7.05),PTB (ORadj = 1.15, 95% CI: 0.76-1.74), and LBW(ORadj = 1.21, 95% CI: 0.78-2.02) among women with two treatment courses.
Conclusion: Male partner coinfection increased the risks for stillbirth, PTB and LBW, particularly when gestational syphilis treatment was suboptimal. However, this risk could be reduced by adequate treatment.
Keywords: Adverse pregnancy outcomes; Couple infection; Syphilis; Treatment.