Effectiveness of treatment to improve pregnancy outcomes among women with syphilis in Zhejiang Province, China

Objectives: To determine the effectiveness of treatment in improving pregnancy outcomes among women with syphilis.

Methods: This is a retrospective study based on the provincial prevention of mother-to-child transmission of syphilis database. All women with syphilis with singleton pregnancies were recruited. We evaluated their pregnancy outcomes by group-specific analyses according to their treatment time and adequacy.

Results: The syphilis prevalence among pregnant women was 0.3% (4214/1 338 739) in Zhejiang Province, China, during 2013-2014, considering all live births and abortions. Women with singleton pregnancies (3767) were included in the study, including live births and stillbirths (≥28 weeks). The treatment coverage for all women with syphilis was 80.2% (3022/3767), and 68.2% (2062/3022) of the women were treated adequately. Of 745 infants born to untreated pregnant women with syphilis, 1.2% manifested pneumonia, 2.7% asphyxia, 1.6% birth defects, 3.8% congenital syphilis (CS), 14.2% were preterm, 10.1% had low birth weight (LBW) and 3.1% experienced perinatal death. The risks of asphyxia (OR=2.7), CS (OR=3.1), preterm birth (OR=1.5), LBW (OR=1.9) and perinatal death (OR=3.1) were much higher in infants born to mothers treated inadequately than from those treated adequately. Moreover, mothers with syphilis who initiated treatment in the third trimester suffered an increased risk for asphyxia (OR=3.0), CS (OR=6.0) and LBW (OR=1.7) compared with those who initiated treatment in the first trimester.

Conclusions: Early and adequate treatment could improve the adverse pregnancy outcomes among women with syphilis.