Table 3.

Descriptions of Congenital Syphilis Cases

Case	Diagnosis	Maternal Syphilis Labs and History	Maternal Syphilis Treatment	Late or Scant Prenatal Care	Infant GA	Infant Syphilis Labs	Infant Symptoms and Additional Evaluation	Maternal Psychiatric History	Maternal Substance Use
1	Highly probable congenital syphilis	- EIA reactive, RPR 1:16; tested at 20 wk + 2 d GA - EIA reactive, RPR 1:16; tested at 34 wk + 6 d GA - RPR reactive; tested at delivery - Two prior treated syphilis infections, most recent infection was <1 y from first prenatal test	Not treated because patient completed syphilis treatment within the past year with decreasing RPR titers	Scant and late prenatal care, first visit at 20 wk + 2 d GA	Late preterm, 35 wk + 2 d GA	RPR ≤4-fold maternal titer, treponemal test not obtained	- Long bone radiographs abnormal with metaphyseal lucent bands - Normal physical exam, CBC, CSF analysis	Adjustment disorder	Marijuana
2	Highly probable congenital syphilis	- RPR 1:2, treponemal test not obtained; tested at 12 wk + 5 d GA - EIA reactive; RPR 1:2; tested at 28 wk + 2 d GA - Prior treated syphilis infection >1 y from first prenatal test - Serofast	Not treated	Adequate, first visit at 6 wk + 2 d GA	Term, 38 wk + 0 d GA	Treponemal test reactive, RPR ≤4-fold maternal titer	- Thrombocytopenia and leukopenia - Hypoglycemia - CSF abnormal with pleocytosis (>25 WBCs/mL) and elevated protein (>150 mg/dL); VDRL NR - Normal physical exam, LFTs	None	None
3	Highly probable congenital syphilis	- Diagnosed at outside clinic at 14 wk + 1 d GA (unknown test type or titer) - EIA reactive, RPR 1:16; tested at delivery - No prior syphilis diagnosis or treatment	Inadequately treated; received 2 of 3 doses with second dose <4 weeks before delivery	Late prenatal care, first visit at 14 wk + 1 d GA	Term, 39 wk + 5 d GA	RPR ≤4-fold maternal titer, treponemal test not obtained	- Leukopenia - CSF abnormal with pleocytosis (>25 WBCs/mL); VDRL NR - Normal physical exam	None	None
4	Highly probable congenital syphilis	- Diagnosed initially at outside hospital, but date unknown and results not confirmed - EIA reactive, RPR 1:32; tested at 31 wk + 5 d GA - RPR 1:16; tested at delivery - No prior syphilis diagnosis or treatment	Completed treatment (3 penicillin doses) > 4 wk before delivery	Scant and late prenatal care, first visit at 15 wk + 2 d GA	Term, 38 wk + 4 d GA	Treponemal test reactive, RPR ≤4-fold maternal titer	- CSF abnormal with pleocytosis (>25 WBCs/mL), elevated protein (>150 mg/dL); VDRL NR - Normal physical exam, CBC, long bone radiographs	Bipolar I disorder with active SI and psychiatric hospitalization during pregnancy	Marijuana
5	Possible congenital syphilis	- EIA reactive, RPR NR; tested at 31 wk + 2 d GA - EIA positive, RPR NR; tested at delivery - No prior syphilis diagnosis or treatment	Received treatment at delivery (<4 wk before delivery)	Late prenatal care, first visit at 15 wk + 1 d GA	Term, 39 wk + 4 d GA	Treponemal test reactive, RPR not obtained	Normal physical exam, long bone radiographs, CBC	None	None
6	Possible congenital syphilis	- RPR NR, treponemal test not obtained; tested at 17 wk + 1 d GA - EIA reactive, RPR NR (tested at delivery) - Test results consistent with serofast serology, but prior syphilis infection only partially treated (1 of 3 penicillin doses received)	Received treatment at delivery (<4 wk before delivery)	Late prenatal care, first visit at 19 wk + 1 d GA	Term, 39 wk + 5 d GA	Treponemal test reactive, RPR ≤4-fold maternal titer	Normal physical exam, long bone radiographs, CBC. CSF obtained, but inadequate sample for testing	None	Marijuana
7	Possible congenital syphilis	- EIA reactive, RPR NR; tested at 6 wk + 6 d GA - EIA reactive, RPR NR; tested at 22 wk + 2 d - No prior syphilis diagnosis or treatment	Inadequately treated; received 2 of 3 penicillin doses	Adequate, first visit at 4 wk + 6 d GA	Preterm, 33 wk + 1 d GA	Treponemal test reactive, RPR ≤4-fold maternal titer	Normal physical exam, long bone radiographs, CBC, LFT, CSF analysis	Bipolar II disorder, major depressive episode with SI	Methamphetamine (ecstasy), marijuana, alcohol use during pregnancy
8	Possible congenital syphilis	- EIA reactive, RPR 1:32; tested at 15 wk + 4 d GA - RPR 1:4; tested at 32 wk + 3 d GA - EIA reactive, RPR 1:16; tested at delivery (4-fold increase in RPR titer indicating reinfection) - No prior syphilis diagnosis or treatment	Completed treatment for initial diagnosis (3 penicillin doses) >4 wk before delivery. Not treated for reinfection diagnosed at delivery	Late prenatal care, first visit at 15 wk + 4 d GA	Term, 41 wk + 0 d GA	Treponemal test reactive, RPR ≤4-fold maternal titer	Normal physical exam, CBC, CSF analysis. CSF VDRL unable to be performed in lab	None	None

Bolded terms indicate key information that determined how cases were determined when the 2018 American Academy of Pediatrics Red Book Diagnostic Algorithm for Infants Born to Mothers with Reactive Syphilis Serologic Tests was applied. Significant associations for psychiatric and substance use history are also bolded.

Abbreviations: CBC, complete blood count; CSF, cerebrospinal fluid; EIA, enzyme immunoassay; GA, gestational age; LFT, liver function test; NR, nonreactive; RPR, rapid plasma reagin; SI, suicidal ideation; VDRL, Venereal Disease Research Laboratory (nontreponemal) test; WBCs, white blood cells.