Study characteristics.

RPR, rapid plasma regain test; VDRL, venereal disease research laboratory test; TPHA, Treponema pallidum haemagglutination testing; TPPA, Treponema pallidum particle agglutination assay; FTA-Abs/FTA IgM, fluorescent treponemal antibody absorbed test; MU, million units; SD: standard deviation; n, number of patients presenting the outcome. All adverse pregnancy outcomes (APOs) included: low birth weight, stillbirth, and preterm birth for Watson-Jones 2002; low birth weight, preterm birth, intrauterine death for Carles 2008; congenital syphilis, foetal death, and neonatal death for Zhu 2010.
*Estimate value from reported distribution.

RPR：快速血浆反应素试验（rapid plasma regain test）；VDRL：性病研究实验室试验（venereal disease research laboratory test）；TPHA：梅毒螺旋体血凝试验（Treponema pallidum haemagglutination testing）；TPPA：梅毒螺旋体颗粒凝集试验（Treponema pallidum particle agglutination assay）；FTA-Abs/FTA IgM：荧光螺旋体抗体吸收试验（fluorescent treponemal antibody absorbed test）；MU：百万单位（million units）；SD：标准差（standard deviation）；n：出现对应结局的患者例数。所有不良妊娠结局（APOs）具体包括：Watson-Jones 2002的研究纳入低出生体重、死产及早产；Carles 2008的研究纳入低出生体重、早产、宫内死亡；Zhu 2010的研究纳入先天性梅毒、胎儿死亡及新生儿死亡。* 基于报告分布的估算值。