[Relationship between computerized cardiotocography and perinatal outcomes]

To analyze the relationship between the parameters of computerized cardiotocography (CTG) and perinatal outcomes.

Three hundred and eight CTG examination in 190 third trimester pregnancy were performed, 46 cases in antepartum, 262 cases in intrapartum. CTG parameters including: baseline fetal heart rate (BHR), the square root of the mean squared differences (RMSSD), the proportion derived by dividing the number of differences greater than 3 beats/min by the total number (NN50), acceleration (AC), deceleration (DC), amplitude of deceleration (AMP), duration of deceleration from BHR to bottom (T1) and duration from bottom to BHR (T2), the ratio of T2 to T1 (T2/T1), square of deceleration (DS), the ratio of AMP to duration of deceleration (H/T), the ratio of DS to the product of AMP multiplied deceleration duration (S/HT), amplitude of uterine contraction (UTAMP), number of uterine contraction (UTNO), duration of uterine contraction (UTDUR), square of uterine contraction (UTS), the ratio of AMP to UTAMP (HR/HU), the ratio of DS to UTS (SR/SU), the ratio of DS to UTAMP (SR/HU). After childbirth record neonatal Apgar scores, amniotic fluid colour (COL) and volume (VOL), umbilical cord arteria blood gas analysis.

(1) The fetal heart rate (FHR) baseline and variability . In antepartum, there were significantly relationship between BHR and Apgar (r = 0.460, P < 0.01), RMSSD and COL (r = - 0.389, P < 0.05), NN50 and COL (r = - 0.368, P < 0.05), RMSSD and actual base excess (ABE) (r = 0.904, P < 0.05), NN50 and ABE (r = 0.919, P < 0.05), AC and ABE (r = 0.943, P < 0.05), BHR and SO2 ( r = - 0.895, P < 0.05). But during intrapartum, there were no significantly relationship between the baseline and variability of CTG with the Apgar scores, the quality and color of amniotic fluid, and the indexes of blood gas analysis of umbilical artery blood. (2) The deceleration of FHR. During antepartum there were significantly relationship between Apgar and AMP (r = - 0.472, P < 0.05), Apgar and H/T (r = - 0.526, P < 0.05), COL and AMP (r = 0.447, P < 0.05), COL and H/T (r = 0.543, P < 0.05) . During intrapartum the relationship of COL and T1 was significant (r = - 0.205, P < 0.05), there were significantly relationship between PH and H/T (r = 0.386, P < 0.05), ABE and H/T (r = 0.367, P < 0.05), Apgar and UTDUR (r = 0.149, P < 0.05), Apgar and UTS (r = 0.148, P < 0.05), PO2 and UTS (r = 0.234, P < 0.05), PO2 and UTNO (r = -0.246, P < 0.05), HCO3 and UTAMP (r = - 0.265, P < 0.05), TCO2 and UTAMP (r = - 0.268, P < 0.05), HCO3 and HR/HU (r = 0.385, P < 0.01), TCO2 and HT/HU (r = 0.385, P < 0.01), ABE and HR/HU (r = 0.323, P < 0.05).

In antepartum, the baseline and variability of FHR play a more important role in predicting prenatal outcome than any other parameters; during intrapartum deceleration become more important, but with the affect by uterin contraction, the ratio of HR/HU may be useful during intrapartum.