Diagnostic accuracy of fetal scalp lactate for intrapartum acidosis compared with scalp pH.

OBJECTIVE: To determine the diagnostic accuracy of fetal scalp lactate sampling (FSLS) and to establish an optimal cut-off value for intrapartum acidosis compared with fetal scalp pH. METHODS: A 20-month retrospective cohort study was conducted of all neonates delivered in our institution for whom fetal scalp blood sampling (FSBS) was performed, matching their intrapartum gasometry to their cord gasometry at delivery (n=243). The time taken from the performance of scalp blood sampling to arterial umbilical cord gas acquisition was 45 min at most. Five arterial cord gasometry patterns were set for assessing the predictive ability of both techniques. Subsequent obstetric management for a pathological value was analysed considering the use of both techniques. RESULTS: The optimal cut-off value for FSLS was 4.8 mmol/L: this value has 100% sensitivity and 63% specificity for umbilical arterial cord gas pH≤7.0 and base deficit (BD)≥12 detection, and 100% sensitivity and 64% specificity for umbilical arterial cord gas pH≤7.10 and BD≥12 detection, with a false negative rate of <1.3%, improving fetal scalp pH performance. FSLS showed the best area under the curve (AUC) of 0.86 and 0.84 for both arterial cord gasometry patterns, respectively. Expedite birth following lactate criteria would have been the same as following pH criteria (92 obstetric interventions) with no cases of missed metabolic acidosis. In the cohort, 19.8% of cases were discordant, but no cases of metabolic acidosis were in this group. CONCLUSIONS: FSLS improves the detection of metabolic acidosis via fetal scalp pH with an optimal cut-off value of 4.8 mmol/L. FSLS can be used without increasing obstetrical interventions or missing metabolic acidosis.

[Prenatal diagnosis of retroperitoneal neuroblastoma. Case report]. / Diagnóstico prenatal de neuroblastoma retroperitoneal. Reporte de un caso.

Neuroblastoma is the foremost malignant neoplasm of the fetus and neonate. It is a tumor of the sympathetic nervous system that originates from the neural crest which etiology is largely unknown. Due to its general variability in outcome, neuroblastoma has long been considered one of the most enigmatic of cancers. Although technological advances in ultrasonography have possible intrauterine detection, prenatal diagnosis is still a rare event. This kind of tumor has a high morbidity and mortality rate due to the metastatic risk. Early detection of the tumor is critical to improve outcome. We report a case of retroperitoneal neuroblastoma diagnosed at 32 week of gestation.