Re: Effect of delayed versus early umbilical cord clamping on neonatal outcomes and iron status at 4 months: a randomised controlled trial
We thank Dr Rashmi R Das for the rapid response. Dr Das ask why we chose ≤ 10sec to define early cord clamping (ECC), and ≥ 180 sec to define delayed cord clamping (DCC).
Immediate clamping was the routine at the time for the study at the hospital where the study was performed. This was motivated by the need to obtain blood gas samples from the umbilical cord before the newborn started to breathe. A majority of hospitals in Sweden had the same routine in 2008, when the study was commenced.
As for delayed clamping, as Dr Das writes, it can be established that the transfusion from the placenta to the newborn takes up to 3 minutes, and that after that time there do not seem to be any more blood transferred. In our study, we wanted the transfusion to be as large as possible, to be able to study effects, both presumed and expected.
Dr Das correctly have remarks regarding scarcity of data on maternal morbidity and other factors from an obstetrical point of view. Among the factors Dr Das mentions are post-partum haemorrhage, risk of blood transfusion and duration of the third stage of labour.
In our paper we write that secondary outcomes “will be reported separately: maternal post-partum haemorrhage and rates of successful umbilical arterial blood samples in relation to allocation group”. This paper is in manuscript and will be submitted shortly, and here we will also report our findings on the mother’s risk of blood transfusion and duration of the third stage of labour.
Finally, Dr Das also misses a description about the neonates in the delayed cord clamping group who had Apgar score < 7 at one minute after delivery. According to the resuscitation protocol at the hospital, these newborns had their umbilical cord cut earlier than 180 seconds, and were handled in all means after what their condition needed. The results from these infants has been included in the delayed cord clamping group according to “intention to treat” although the protocol was not followed.
As Dr van Rheenen writes in the editorial accompanying this paper, it is suggested to delay clamping also in newborns that require immediate neonatal resuscitation. Although very interesting and important, we did not design our study for this outcome.
Competing interests: No competing interests