The infant was a very low birth weight premature infant delivered by cesarean section at 31+4 weeks of gestation. The mother was an elderly pregnant woman with syphilis

and she had completed the standard full-course anti-syphilis treatment during pregnancy. After birth due to premature birth and severe asphyxia

the infant was transferred to the pediatric department for symptomatic treatment after resuscitation. From birth to three months of age

the serum syphilis treponemal antibody (Syphilis TP) and toluidine red unheated serum test (TRUST) were dynamically followed up. After multi-dimensional investigation to exclude detection errors

the results showed that: Syphilis TP was positive

and TRUST and all titers were negative on the first day after birth; Syphilis TP was weakly positive at 2 months of age

and TRUST was still negative; Syphilis TP turned negative at 3 months of age. It was considered to be maternal passive transfer of syphilis antibodies. Anti-syphilis treatment was not given

and only symptomatic treatment was provided. After the treatment course

the condition was stable and the infant was discharged from the hospital. Follow-up indicated that the antibodies gradually turned negative

and there was no adverse prognosis.