Serum amyloid A as a diagnostic marker for histologic chorioamnionitis in preterm premature rupture of membranes: A diagnostic accuracy study.

BACKGROUND

Chorioamnionitis is an acute inflammation of the fetal membrane in mothers with preterm premature rupture of the membrane (PPROM). The diagnosis of chorioamnionitis is based on clinical findings; however, laboratory tests may help diagnose the disease.

OBJECTIVE

It aimed to evaluate the accuracy of maternal serum-amyloid A (SAA) protein levels in diagnosing histopathologic chorioamnionitis following PPROM mothers; secondarily, it assessed their accuracy for diagnosing clinical chorioamnionitis.

MATERIALS AND

METHODS

In this diagnostic accuracy study, 94 PPROM pregnancies, referred to Namazi, Hafez, and Zeinabiyeh hospitals, Shiraz, Iran, from March 2022 to March 2023 were followed. All placentas were examined for histopathological evidence of chorioamnionitis, and participants were classified into 2 pathologic chorioamnionitis and normal placenta groups.

RESULTS

From the 94 participants, 50 (43.20%) were pathologically diagnosed with chorioamnionitis as pathologic chorioamnionitis group, and the remaining 44 (46.80%) belonged to control "normal placenta group". In addition, 50% (25/50) of women with pathological chorioamnionitis were clinically diagnosed with chorioamnionitis as clinic chorioamnionitis group, and the remaining 50% (25/50) with no clinical signs of chorioamnionitis belonged to their control. Pathologic at-delivery SAA were more in the pathologic chorioamnionitis group compared with normal placenta group; adjusted odds ratio (95% confidence interval); 15.20 (2.62-88.20); the area under curve values (cutoff point, sensitivity, specificity, negative predictive value, positive predictive value, and accuracy) were 0.83 ( > 0.54 mg/dl, 95%, 70%, 86%, 88%, and 84%) for pathologic at-delivery SAA. However, clinic at-delivery SAA did not significantly change between clinic chorioamnionitis group and not having clinic chorioamnionitis. A no-clinic chorioamnionitis PPROM mother could be chorioamnionitis one by a 50% chance, even with no clinical sign.

CONCLUSION

Pathologic at-delivery SAA level could be a supplementary test in PPROM mothers. At-delivery SAA serial measurements and long-term evaluation of infants born to these mothers are recommended.