Neonatal Outcomes of Mothers with Syphilis During Pregnancy: A Retrospective Single Center Experience.

Objective: Syphilis during pregnancy can be easily missed with potential severe outcomes of the newborns, including congenital syphilis (CS). We report the neonatal outcomes of a cohort of mothers with syphilis during pregnancy.

Methods: a retrospective cohort study in a referral university hospital in Rome, enrolling mother/newborn couples followed up from 2016 to 2023 by a multidisciplinary team including infectious disease specialists, obstetricians, microbiologists, neonatologists and pediatricians. Primary outcome was the assessment of risk factors for development of congenital syphilis (CS) in the newborns.

Results: Fifty-three pregnant women (median age 34, IQR 29-37 years) with documented syphilis in pregnancy have been included in this study. 50/52 (96.2%) were treated during pregnancy, and forty of them (80%) received adequate treatment. Fifty-three newborns were born from mothers with syphilis during pregnancy (female 25/48, 52.1%). Four newborns were classified as CS (7.5%), and two newborns as probable CS (3.8%). Newborns with CS were born more frequently from mothers treated inadequately (p 0.02), had higher probability of neonatal intensive care unit admission (p < 0.001), had a higher Venereal Disease Research Laboratory (VDRL) titer (p 0.076), higher ALT (p 0.005). Univariate logistic regression conducted on the development of CS showed an adequate treatment as a protective factor (OR 0.03; 95% CI: 0.002; 0.31; p = 0.002), while later weeks of pregnancy for the beginning of treatment as a risk factor (OR 1.24; 95% CI: 1.02; 1.51; p = 0.026).

Conclusions: Syphilis still represents a potential problem for women of childbearing age and their newborns, even in a high-income setting, making congenital syphilis far from being eradicated in Italy. Moreover, adequate and early treatment should be provided to avoid negative consequences to the newborns.