title: Reported estimates of adverse pregnancy outcomes among women with and without syphilis: a systematic review and meta-analysis.
abstract: BACKGROUND
  To estimate probability of adverse pregnancy outcomes (APOs) among women with and without syphilis through a systematic review of published literatures.
  
  
  RESULTS
  Chinese and English literatures were searched for studies assessing pregnancy outcomes in the presence of maternal syphilis through August 2013. The prevalence estimates were summarized and analyzed by meta-analysis. Fifty-four literatures involving 11398 syphilitic women and 43342 non-syphilitic women were included from 4187 records initially found. Among untreated mothers with syphilis, pooled estimates were 76.8% for all APOs, 36.0% for congenital syphilis, 23.2% for preterm, 23.4% for low birth weight, 26.4% for stillbirth or fetal loss, 14.9% for miscarriage and 16.2% for neonatal deaths. Among syphilitic mother receiving treatment only in the late trimester (>28 weeks), pooled estimates were 64.4% for APOs, 40.6% for congenital syphilis, 17.6% for preterm, 12.4% for low birth weight, and 21.3% for stillbirth or fetal loss. Among syphilitic mothers with high titers (≥1∶8), pooled estimates were 42.8% for all APOs, 25.8% for congenital syphilis, 15.1% for preterm, 9.4% for low birth weight, 14.6% for stillbirth or fetal loss and 16.0% for neonatal deaths. Among non-syphilitic mothers, the pooled estimates were 13.7% for all APOs, 7.2% for preterm birth, 4.5% for low birth weight, 3.7% for stillbirth or fetal loss, 2.3% for miscarriage and 2.0% for neonatal death. Begg's rank correlation test indicated little evidence of publication bias (P>0.10). Substantial heterogeneity was found across studies in the estimates of all adverse outcomes for both women with syphilis (I2 = 93.9%; P<0.0001) and women without syphilis (I2 = 94.8%; P<0.0001).
  
  
  CONCLUSIONS
  Syphilis continues to be an important cause of substantial perinatal morbidity and mortality, which reminds that policy-makers charged with resource allocation that the elimination of mother-to-child transmission of syphilis is a public health priority.
authors.affiliation: Department of Epidemiology and Health Statistics, School of Public Health, Central South University, Hunan, China.
authors.forename: Jiabi
authors.initials: J
authors.lastname: Qin
authors.affiliation: Department of Epidemiology and Health Statistics, School of Public Health, Central South University, Hunan, China.
authors.forename: Tubao
authors.initials: T
authors.lastname: Yang
authors.affiliation: Department of Social Medicine, School of Public Health, Central South University, Hunan, China.
authors.forename: Shuiyuan
authors.initials: S
authors.lastname: Xiao
authors.affiliation: Department of Epidemiology and Health Statistics, School of Public Health, Central South University, Hunan, China.
authors.forename: Hongzhuan
authors.initials: H
authors.lastname: Tan
authors.affiliation: Department of Dermatology and Venereal Disease, Shenzhen Center for Chronic Disease Control and Prevention, Shenzhen, China.
authors.forename: Tiejian
authors.initials: T
authors.lastname: Feng
authors.affiliation: Department of Epidemiology and Health Statistics, School of Public Health, Central South University, Hunan, China.
authors.forename: Hanlin
authors.initials: H
authors.lastname: Fu
mesh_terms: D016022:Case-Control Studies; D005260:Female; D006801:Humans; D011247:Pregnancy; D011256:Pregnancy Outcome; D013587:Syphilis / Q000503:physiopathology*