PREDICTION OF FETAL ACIDEMIA IN INTRAUTERINE GROWTH-RETARDATION - COMPARISON OF QUANTIFIED FETAL ACTIVITY WITH BIOPHYSICAL PROFILE SCORE

Objective To study the relation between quantified fetal movements and fetal activity assessed by the biophysical profile score and the pH i n umbilical arterial blood at elective caesarean section. Design Fetal activity was assessed within 24 h prior to caesarean section for dece lerative fetal heart rate patterns both by quantification (% of time s pent moving) and by applying the biophysical profile score (BPS) crite ria. Setting Department of Obstetrics, University Hospital. Subjects N ineteen growth retarded fetuses. Main outcome measures Fetal generalis ed movements (FGM%), fetal breathing movements (FBM%), total fetal act ivity (TFA% = FGM% + FBM%); FGM, FBM and tone as assessed according th e biophysical profile score (BPS); umbilical arterial pH.Results In al l 11 acidaemic fetuses (pH <7.20) TFA% was below the 10th centile for normal fetuses; nine had decreased FGM% and eight decreased FBM%. Abse nce of FGM or tone according to the biophysical profile score was only seen in two acidaemic fetuses. Conclusion TFA% <11.7% was a better pr edictor of acidaemia at birth than either reduced FGM%, FBM%, or absen ce of FGM, FBM and tone as defined in the biophysical profile score. T he two methods of assessing FBM were identical in predicting acidaemia , suggesting that in presence of acidaemia the decrease of FBM may be an all-or-none phenomenon. Furthermore, the data indicate that reducti on in body movements may precede reduction in breathing movements.