Amniotic fluid erythropoietin concentrations differentiate between acute and chronic causes of fetal death.
BACKGROUND
Increased fetal plasma erythropoietin concentration is an indicator of chronic fetal hypoxia. Amniotic fluid erythropoietin levels correlate highly significantly with fetal erythropoietin levels before labor. We studied AF erythropoietin levels after fetal death in order to determine whether this could differentiate between stillbirths from acute or chronic causes.


METHODS
Amniotic fluid was obtained after fetal death for erythropoietin measurement following fetal death in 21 pregnancies. Two of the pregnancies had twins, of which one infant was born alive. All 22 stillborn fetuses had an autopsy. None had malformations. Without prior knowledge of the results of the erythropoietin analyzes, the causes of fetal death were divided into acute, chronic or unknown groups.


RESULTS
Eight pregnancies had an acute cause of fetal death (e.g. cord complication or placental abruption), eight pregnancies had a chronic cause (intrauterine growth restriction or erythroblastosis) and in five pregnancies the cause of fetal death could not be determined. In all eight pregnancies with an acute cause of fetal death, AF erythropoietin levels were normal (< 20 mU/mL). In contrast, six of the eight pregnancies with a chronic cause had AF erythropoietin levels above normal (range from 49.9 mU/mL to 391 mU/mL). In the five pregnancies with an unknown cause of fetal death, AF erythropoietin levels were normal in three and elevated in two.


CONCLUSIONS
Elevated AF erythropoietin levels, identified after fetal death, suggest that the fetus died from a chronic hypoxic event, whereas normal AF erythropoietin levels suggest that the fetus died from an acute event.
Teramo
Kari A
KA
Department of Obstetrics and Gynecology, University Central Hospital, PO Box 140, Fin-00290 Helsinki, Finland. Kari.Teramo@huch.fi
Schwartz
Robert
R
Clemons
Gisela K
GK
Widness
John A
JA
D000208:Acute Disease / Q000401:mortality*; D000653:Amniotic Fluid / Q000737:chemistry*; D001831:Body Temperature; D002423:Cause of Death; D002908:Chronic Disease / Q000401:mortality*; D004921:Erythropoietin / Q000032:analysis*; D005260:Female; D005313:Fetal Death / Q000209:etiology*; D005315:Fetal Diseases / Q000401:mortality*; D006801:Humans; D066298:In Vitro Techniques; D011247:Pregnancy; D013997:Time Factors
D004921:Erythropoietin