Objective:
To evaluate the influence of mode of delivery on repolarisation and QT interval in the neonatal electrocardiogram (ECG).

Study design:
KUNO-Kids is a prospective, population-based birth cohort study. Neonates received an ECG within the first week of life; subgroups were divided according to mode of delivery. Effects on neonatal QT interval were tested by linear and logistic regression analyses, adjusting for age at ECG recording.

Results:
In total, 712 neonates were included. The primary caesarean section group showed a significant higher mean QTc (regression coefficient 6.03, p = 0.033) and a significantly increased rate of prolonged QTc >450 ms (odds ratio 2.4, p = 0.042), compared to the spontaneous delivery group.

Conclusion:
The mode of delivery has a significant effect on neonatal QTc. Clinicians should consider this influence when deciding on postnatal and follow-up examinations, regarding additional risk factors for acquired long QT interval.