(215) Updated Ultrasonographic Fetal Indicators of Congenital Syphilis

Objective:

This study aims to identify updated ultrasonographic (US) markers of congenital syphilis (CS) in exposed fetuses and examine their association with neonatal CS classification.

Study Design:

Following institutional approval, a prospective study of pregnant women with syphilis and their neonates was performed between 05/23-06/25 at the University of Texas in Houston. All consented participants >16 weeks gestational age (GA) underwent serial (US) evaluation within 7 days of maternal treatment and monthly thereafter. We evaluated several traditional US findings of CS (i.e., placentomegaly ( >2SD for GA) and hepatomegaly ( >90% for GA) versus longitudinal estimated fetal weight (EFW) and femur length (FL) measurement percentiles as predictors for neonatal CS categories. All measurements were compared to established nomograms. Logistic regression was used to evaluate associations between sonographic measurements and neonatal CS and linear mixed-effects models for trends in fetal growth parameters and CS categories.

Results:

Of 84 enrolled pregnant women, eleven (13%) were diagnosed with early syphilis and 47 (56%) were diagnosed < 20 weeks GA. No fetal deaths were reported. Among 84 neonates, 16 (19%) were classified as confirmed/highly probable CS, 8 (10%) as possible CS, and 60 (71%) as less-likely CS. Sixty-four newborns (76%) had antenatal serial growth data. Placentomegaly was common across all CS groups (Table 1) and hepatomegaly was significantly associated with confirmed/highly probable CS (p=0.002). In addition to these traditional CS findings, FL percentile decreased by 2.5 points (95%CI:-0.63,-1.39) and EFW percentile by 1.7 points (95%CI:-2.94,-0.46) at each successive scan. Neonates with FL ≤10th percentile had significantly higher odds of confirmed/highly probable CS (OR 3.63, 95%CI:1.02–12.9, p=0.046) (Figure 1).

Conclusion:

In addition to traditional US stigmata of CS, most fetuses exposed to syphilis experienced significant growth abnormalities, especially in FL. US growth assessment might be considered as part of an antenatal US evaluation in the context of syphilitic infection.