This study indicates improvement in syphilis screening and treatment in pregnant women, especially the narrowed gap between local residents and migrants. In 2020, vast majority of pregnant women were screened for syphilis in their ANC, over 95% maternal syphilis received therapy, congenital syphilis (CS) incidence was at a low level, meeting the global goals of EMTCT4.Between 2012 and 2016, and coverage of syphilis testing increased from 59–66%, and treatment increased from 74–78% all over the world 1. At Chinese national level, treatment coverage reached 89.52% in 2019, and remarkable achievements on EMTCT of syphilis have also been reported at regional level at home and abroad11, 17–21 .Findings in our study reflected persistent progress towards EMTCT over the past years as a pilot area. EMTCT program were enhanced and financed by both Chinese and Zhejiang local government, promoting accessibility and equality of services. EMTCT has been integrated with current basic ANC services for women in Zhejiang, an increase in coverage of early ANC as well as sustainable provision of Penicillin also contributed to the improvement.
Maternal syphilis incidence has remained at high level throughout the study period in Zhejiang. In 2020, it reached 0.44%, which is higher than the Netherlands (0.06–0.08%), lower than Africa (2.7%), Latin American (1.1%) and Beijing(China) (1.4‰), however similar to Shanghai (0.20–0.38%)(China).19, 21–28The epidemic of maternal syphilis in this study is slightly expanded compared to the previous study of Zhejiang in 2013-2014.16 As the global maternal syphilis remained stable in most area, the growth of syphilis in pregnant women in Zhejiang should be given serious consideration.1On the one hand, it should be possible due to changes in sexual network structure and increase in screening. On the other hand, growth in multipara with syphilis would also result in increase of maternal syphilis prevalence.
Early ANC is critical for timely intervention and adequate treatment. During 2015 to 2020, ANC in first trimester increased by 6.71% annually. Consequently, the most increase was found to be adequate therapy among women, rising by 4.84% per year, and 6.89% increase in migrants. The findings prove the effective because we gave case reviews on those women delayed early ANC, inadequate treatment or vertical transmission since 2017.Barriers to access early ANC or effective EMTCT services were comparable to other studies, such as poor awareness of ANC in pregnant women, limited EMTCT knowledge in healthcare providers, vulnerabilities in laboratory facilities as reported elsewhere.22,24−25One step of screening and treatment package should been strengthened for improvement of follow up as widely suggested.23–24
We evaluated the characteristics of women with syphilis in order to develop target interventions. The proportion of women with advanced age(≥ 35years) increased greatly, exceeding 20%.The rapid development of social-economy, work and lifestyle pressure ,might force women to put off giving birth, particularly since the new birth policy changes in China.29–30Similarly,reports indicated that women with syphilis infection were more likely to be illiterate, migrants and multiparous at regional and national level.11,17Furthermore, a rise in pregnancy complications proportion in women with syphilis might be the consequence of increasing number of women with advanced age and higher parity. This point highlighted the need for the potential improved risk management for APOs.
The average incidence of APOs at our national level was 13.82% in 2016–2019, reflecting fetal loss or stillbirth, as well as abnormal infant parameters. In Guangzhou, this figure was 27.3% during 2011–2018, including ectopic pregnancy, spontaneous abortion, stillbirth, prematurity or LBW, a live infant birth weight of less than the 10th percentile by gestational age and sex, infant death and CS.31 Therefore, differences in inclusion and exclusion criteria in different studies while comparing the overall occurrences of APOs should be given consideration. Exclusion of early fetal loss in our study resulted in decreased incidence of APOs for this reason the incidence of APOs might be underestimated. LBW/preterm birth was the most common subtypes of APOs, which was shown in previous studies.4, 11, 31 No significant decline in LBW/preterm birth was possible for the composite negative effect from increasing maternal age and pregnancy complications. The obvious reduction of APOs categories were predominantly in CS, abnormal signs and perinatal death. Our hypothesis indicates increasing coverage and effectiveness of testing, early ANC, and treatment. Women with treatment, especially adequate treatment, early ANC and appropriate maternal age were less likely to experience APOs. APOs risk increased with maternal RPR/TRUST titers, which was significantly severe among women with atiter of ≥ 1:32 at delivery or third trimester. The above evidences have been widely reported, and persisting low nontreponemal titers (< 1:8) is frequently suggested. 2–5, 11, 31
This study has several limitations. Firstly, we focused on selected APOs. Missing information on early fetal loss and abortion could lead to some selection bias to the comprehensive understanding of APOs associated with syphilis. Secondly, some risk factors, such as the mother's stage of syphilis infection, gestational age at syphilis status, mode of delivery, sexual partner’s infection status and congenital birth defects, were not considered.5,11,26 Lastly, Zhejiang is a province with rapid economic growth and with qualified healthcare system. The lessons from Zhejiang's experiences need to be considered cautiously by other less developed regions.