It is generally agreed that the signs of fetal distress are alterations in the fetal heart rate, fetal acidosis and the passage of meconium and it is also agreed that a fetus in serious danager from asphyxia will show these signs.
The study subjects were 124 pregnant women, who admitted to Yeungnam University Hospital for delivery from July to December 1992 and shown grossly meconium-stained amniotic fluid at the time of amniotomy.
The purposes of this study were evaluating the relationship between the amount of the meconium contained in amniotic fluid as measured by the meconiumcrit and currently accepted markers of birth asphyxia, as the 1-and 5-minute Apgar scores,
umbilical
cord arterial blood pH and fetal heart rates and examining the clinical usefulness of meconiumcrit in labor as predictor of subsequent fetal distress.
To measure the amount of meconium or solid component of amniotic fluid quantitatively, the amniotic fluid was centrifused and classified into three groups by the meconiumcrit; thin (less than 10%), moderate (10 to 30%) and thick (over 30%0
groups.
Of
the 124 patients, 63(50.8%) had thin meconium, 34 (27.4%) had moderate meconium and 27 (21.8%) had thick meconium.
Although the amniotic fluid index was within normal limit in all cases, the lower amniotic fluid index, the higher meconiumcrit i.e. thick amniotic fluid.
The 1-and 5-minute Apgar scores in the thick group were lower than the thin and moderate groups, but there was no significant difference between the thin and moderate groups.
There was no difference in the incidence of meconium aspiration syndrome and no significant change in fetal heart rate in three groups.
It the umbilical cord arterial blood gas analysis, the mean value of pH was lower and the frequency of acidemia was higher in the thick group than the other two groups.
The mean value of pCO2 was higher and the degree of base deficit was more severe but the mean value of the HCO3 was lower in the thick group than the other two groups.
The morbidities and complications of neonates were significantly increased as the umbilical arterial blood pH decreases below 7.20.
If there was no significant change in fetal heart rate, almost all the neonates were healthy and did not show any other evidence of serious sequelae.
These results suggest that determination of the meconiumcrit provide a more objective method of characterizing the type of meconium-staining amniotic fluid and a simple and economic technique to evaluate fetal well-being, and it may be expected a
clinically useful indicator of fetal distress in the labor period.
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