Relationship between Oligohydrmanios and Umbilical Venous Blood Erythropoietin Levels and Nucleated Erythrocyte Counts in Appropriate and Small for Gestational Age Fetuses at Birth

Kim, Tae Eun; Park, Mi Hye; Kim, Young Joo; Ann, Jung Ja; Kim, Jong Il; Chun, Sun Hee

Abstract

OBJECTIVE
The purpose of this study is to assess the relationship between the oligohydramnios and umbilical venous blood EPO levels and nRBC counts, and to investigate the significance of oligohydramnios as intrauterine hypoxic marker in AGA and SGA fetuses.
METHODS
EPO and nRBC were measured in 217 singletons with a gestational age of 32 to 42 weeks at delivery. The subjects were divided into 4 groups: group 1 (AGA with normal amniotic fluid volume, n=129), group 2 (AGA with oligohydramnios, n=15), group 3 (SGA with normal amniotic fluid volume, n=57) and group 4 (SGA with oligohydramnios, n=11). EPO levels and nRBC counts in group 2, 3 and 4 were compared to those in group 1 using Mann-Whitney U-test. Relationship between EPO and nRBC was assessed using linear regression analysis. In addition, relationship between results of umbilical venous blood gas analysis and EPO/nRBC was assessed using the same method. P-values less than 0.05 were considered statistically significant.
RESULTS
EPO levels and nRBC counts in AGA with oligohydramnios (group 2) were not significantly different from those in AGA with normal amniotic fluid volume (group 1). EPO levels in SGA with normal amniotic fluid volume (group 3) were significantly higher than those in AGA with normal amniotic fluid volume (group 1). EPO levels and nRBC counts in SGA with oligohydramnios (group 4) were significantly higher than those in AGA with normal amniotic fluid volume (group 1). There was significant positive correlation between EPO and nRBC. Parameters obtained from the umbilical venous blood gas analysis were more related with nRBC than EPO.
CONCLUSION
Oligohydramnios was significant intrauterine hypoxic marker in SGA fetuses. However, the results of this study suggested that the influence of oligohydramnios on antenatal fetal condition might be less severe in AGA fetuses than in SGA fetuses. Moreover, it was likely that nRBC had stronger association with pathologic hypoxia than EPO did.