Effect of screening and treatment of syphilis among pregnant women on prevention of intrauterine syphilis transmission in Nantong City, 2012-2019 / 中华围产医学杂志

ABSTRACT

Objective:To evaluate the intrauterine transmission of syphilis in Nantong City, Jiangsu Province from 2012 to 2019, after the introduction of a nationwide policy for preventing intrauterine transmission of syphilis in China in 2011.Methods:This study enrolled all live birth deliveries ( n=455 561) in Nantong from January 2012 to December 2019. The screening, infection rates, anti-syphilis treatment, intrauterine transmission of syphilis, and outcomes of infants with congenital syphilis were retrospectively analyzed using χ 2 test for trend, adjusted χ 2 test, or Fisher's exact test. Results:Except for three women, the remaining 455 558 subjects were all screened for syphilis antibody with a total screening rate of nearly 100%, among which prenatal screening accounted for 96.4% (439 125/455 561) and intrapartum screening for 3.6% (16 433/455 561). In total, 796 (0.17%) women were diagnosed with syphilis during pregnancy, and the prevalence increased from 0.13% (85/64 229) in 2012 to 0.24% (110/45 517) in 2019 (χ 2trend=48.985, P<0.001). The prevalence among women underwent intrapartum screening was significantly higher than those underwent prenatal screening [0.50% (82/16 433) vs 0.16% (714/439 125), χ 2=102.769, P<0.001]. Out of the women with syphilis, 716 (89.9%) received anti-syphilis therapy with 695 cases using penicillin, 16 cases using ceftriaxone and five using erythromycin/azithromycin, while the remaining 80 (10.1%) did not. Intrauterine transmission of syphilis occurred in 14 infants with a transmission rate of 1.8% (14/796). The reported rate of congenital syphilis in all live infants was 0.03‰ (14/460 552). The intrauterine transmission rate in women receiving treatment during pregnancy was significantly lower than that in the untreated women [0.4% (3/716) vs 13.8% (11/80), χ2=66.499, P<0.001]. For the untreated women, the intrauterine transmission rate increased with the rising titers of non-specific syphilis antibody ( χ2trend=5.338, P=0.021). Among infants with congenital syphilis, no obvious adverse outcomes occurred in three infants born to treated mothers, whereas the rates of preterm birth and neonatal death were 7/11 and 2/11 in those born to untreated mothers. Conclusions:Since the implementation of the policy against intrauterine transmission of syphilis, the reported rate of congenital syphilis is 3/100 000 live-birth in Nantong City, reaching the national target of below 15/100 000. Screening and treatment in the first trimester are critical for preventing intrauterine transmission of syphilis. Increased prenatal syphilis screening rate can help further reduction of the intrauterine transmission of syphilis.