OBJECTIVETo investigate the pathologic features of histologic chorioamnionitis (HCA) and its impact on newborns.

METHODSFrom Jun.2012 to Dec.2014, 5 810 placentas delivered in our hospital were collected. There were 898 HCA cases and positive rate was 18.3%.Cases with complete clinical data were collected, including 308 cases of infected newbon infants (case group), and 120 cases of non-infected infants(control group). The correlation between pathologic results and neonatal outcome was analyzed.

RESULTSThirty nine cases were premature delivery (39/428, 9.1%). Twenty one cases were small for gestational age (21/428, 4.9%). One hundred and eleven cases were delivered by caesarean section (111/428, 25.9%). Three hundred and eight cases of neonatal infection included 104 cases of hematosepsis, 16 cases of purulent meningitis, 78 cases of infectious pneumonia, 34 cases of infective enteritis, 18 cases of urinary tract infection and 58 cases of skin infection.Placental pathological examination found out 40 cases showed mild HCA (18 cases of neonatal infection, and 22 non-neonatal infection cases), 104 cases showed moderate HCA (88 cases of neonatal infection, and 16 non-neonatal infection cases), and 183 cases showed severe HCA (172 cases of neonatal infection and 11 non-neonatal infection cases). Moderate to severe HCA were easily found in premature infants, with higher positive rate of both late pregnancy group B streptococcus (P<0.05) and afterbirth blood culture (P<0.05). Significantly higher serum C reaction protein (P<0.05) and white-cell count(P<0.05) were also found within moderate to severe HCA patients. Moderate to severe HCA, funisitis and syncytial nodular hyperplasia were associated with neonatal infections (P<0.05), while infarction, intervillous thrombosis and villi thrombus were not observed in the inflammation group (P>0.05).

CONCLUSIONSHCA is often of few clinical symptoms and easily misdiagnosed by placental pathological assessment only. HCA is found associated with intrauterine infection and neonatal infection. Pathological assessment of placenta is valuable in diagnosis and treatment of intrauterine infection.