Materials and methods: In a cross-sectional analytic study, 324 term pregnant women were included, and the association between non-reassuring patterns in cardiotocography (fetal tachycardia, fetal bradycardia, absent or minimal baseline variability, and absence of acceleration and periodic or episodic deceleration) and birth asphyxia were assessed.

Results: Birth asphyxia existed in 10 newborns; in all cases mild hypoxic ischemic encephalopathy was observed. Within the non-reassuring cardiotocography patterns, baseline fetal heart variability and periodic or episodic deceleration had a significant relationship with birth asphyxia. Most asphyxia cases had occurred in absent and minimal baseline fetal heart rate (FHR) variability (R = 0.49, P < 0.001). In periodic or episodic decelerations, most asphyxia cases occurred in recurrent late decelerations with normal baseline variability and variable decelerations with shoulders or overshoots (R = 0.42, P = 0.014).

Conclusion: With regard to the findings of the present study, we can use non-reassuring cardiotocographic patterns, especially absent and minimal baseline FHR variability and periodic or episodic decelerations, in prediction of birth asphyxia. But it seems that most birth asphyxias occur in normal cardiotocographs.