CD15 immunostaining improves placental diagnosis of fetal hypoxia.

INTRODUCTION: Fetal hypoxic events with unclear predictive value are a common indication for placenta examination. We evaluated whether the use of CD15 immunostaining can improve the assessment of severity and duration of fetal hypoxia.

METHODS: We compared placentas (37-42 gestational weeks) from stillborns/newborns with birth asphyxia (BA) and non-hypoxic newborns. Placental findings were studied in following groups: (1) acute BA (n = 11) due to placental abruption, (2) non-acute BA (n = 121) due to non-acute conditions, (3) non-BA (n = 46) in pregnancies with preeclampsia and gestational diabetes, and (4) controls (n = 30).

RESULTS: A high expression of CD15 in feto-placental resistance vessels (FRVs) was present in non-acute BA (95.9%), but absent in acute BA, non-BA and controls (p < 0.0001). Furthermore, we found no causal relationship of high expression of CD15 in FRVs to coexisting placental conditions, including severity and mechanisms/patterns of placental injury, fetal erythroblastosis, and maternal conditions. According to a multivariate analysis, only a high expression of CD15 in FRVs was independently associated with severe non-acute fetal hypoxia ([OR] = 15.52; 95% [CI] = 5.92-40.67).

DISCUSSION: We have defined a characteristic pattern of CD15 expression in FRVs that allows to interpret various clinical/placental conditions with respect to fetal hypoxia, with an improved predictability compared to conventional analyses. This approach represents a novel diagnostic strategy for placenta examination, which could indirectly assess severity and duration of intrauterine hypoxia in a heterogeneous population of newborns.