Maternal arrhythmias detected during labour could be caused by drugs used for induction of labour

Dear Editor,

Ripley et al. (2012) stated that maternal supraventricular tachycardia (SVT) during labour may be associated with increased morbidity, including the risk of emergency caesarean section by presenting a case from their clinic who underwent caesarean section following induction of labour due to failure-to-progress.

In our study, we stated that arrhythmia frequency was higher during and after the labour (82.3%). But none of the cases had severe arrhythmia and patients did not show any serious symptoms except tachycardia during these arrhythmias. So, there was no need for treatment. Sinus tachycardia was the most commonly observed cardiac rhythm disturbance with a frequency of 70.6%. SVT was seen in only 8.8% of women. We thus concluded that arrhythmias that are detected by ECG during or after the labour on patients with no cardiovascular pathology display a benign nature and do not create any clinical risk for the mother and the baby, but symptomatic cases must be treated in a suitable way as stated by Ripley et al. (2012).

Another point we want to mention is that our study group consisted of healthy pregnant women who gave birth spontaneously, without labour induction. The patient mentioned by Ripley et al. (2012) was 40 years old, was not examined for cardiac pathology beforehand (as I understand it, only verbal information about previous cardiac disease was taken from patient). More importantly, the patient was given some medications for labour induction, as the authors stated that prostaglandin and oxytocin were given to the patient for induction of labour, and both of them have arrhythmogenic properties or may aggravate occult cardiac conduction problems (Sung et al. 2009; Ghulmiyyah et al. 2007).

Pregnancy itself causes susceptibility to maternal arrhythmias due to hormonal, haemodynamic and autonomic changes. Medications used for labour induction also must be considered for the cause of persisting arrhythmia during labour.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.