This survey indicates that there is large variation in local routines and guidelines for umbilical cord clamping in Norwegian maternity institutions. We believe that this is a reflection of clinical practice.
Approximately two-thirds of the responding units had no written guidelines. It may appear that units with written guidelines more frequently practice early umbilical cord clamping than units that have no written guidelines. It appears that late umbilical cord clamping is more common in small obstetric departments, while early clamping is practised more frequently in the large obstetric departments. However, ten of 16 large obstetric departments report to practise late umbilical cord clamping of term neonates, while only seven of these units do so for premature infants.
On questions concerning advantages and disadvantages of late vs. early umbilical cord clamping the answers also varied greatly. The majority of the respondents stated that late umbilical cord clamping resulted in higher haemoglobin values in the premature neonate; this is well documented in randomised studies of both premature
(6) and term neonates (1, 4, 17). Answers pertaining to jaundice most likely reflect the fact that the effect of the timing of cord clamping on the prevalence of clinically significant jaundice remains somewhat unclear. However, there appear to be only marginal differences in the prevalence of clinically significant jaundice reported by studies that have compared large groups of infants after late vs. early cord clamping (1, 4, 6, 17).
More than two-thirds of the respondents stated that late umbilical cord clamping may cause a detrimental delay in resuscitation (Table 2, Table 3). In the case of acute, serious asphyxia, in term as well as premature neonates, priority will be given to quick clamping of the umbilical cord in order to initiate resuscitation as quickly as possible. Milking of the umbilical cord will thus provide an opportunity for speeding up the placental transfusion in situations where immediate cord clamping is desirable. In premature infants, studies have shown that milking of the umbilical cord causes higher haemoglobin values, higher blood pressure and less need for transfusions when compared to early clamping without milking of the umbilical cord
(21, 22). Corresponding findings of higher haemoglobin values and improved iron status have been observed after milking of the umbilical cord of term neonates (23).
Half of the large obstetric departments and somewhat less than one-third of the midwife-led units reported to undertake blood-gas analysis from the umbilical cord as a matter of routine for all births (Figure 1). Respondents in 13 of the 16 large obstetric departments responded that one advantage of early umbilical cord clamping was the opportunity it provided to obtain «correct blood-gas values» (Table 2). In our experience it has become common, most likely following the introduction of the STAN methodology
(2, 20), to immediately clamp a section of the umbilical cord to obtain a «correct» blood-gas sample that reflects the metabolic condition of the foetus (24, 25). The pH value and the base excess will fall slightly if the blood-gas analysis is not undertaken until late cord clamping has been performed, and the changes can be observed after no more than 45 seconds (25, 26). Experience and clinical studies show, however, that it is practically feasible to undertake an early blood-gas analysis from the umbilical cord without having to clamp it first (Figure 1). In this manner, the advantages of obtaining a placental transfusion with late cord clamping (27) can be combined with an early blood-gas analysis (9, 17). Some Norwegian hospitals have already recommended this procedure (Ragnhild Støen, St. Olavs Hospital, personal communication).
Figure 1 Collection of a blood sample from the umbilical cord before clamping with artery clamps. A loop of the umbilical cord is clamped with one hand. An arterial and venal sample is collected before the manual stasis is released. Final clamping of the umbilical cord can then be undertaken once pulsation in the umbilical cord has ceased or after at least 1 – 3 minutes.
The objective of this survey was to identify practice in Norwegian maternity wards. We therefore asked the heads of units to describe the routines and practices in their unit. We cannot exclude, however, that attitudes, professional backgrounds (doctor/midwife) and personal preferences are reflected in the responses. Nor did we collect written routines from the units that stated that they had such. The failure of some units to respond to all the questions is another weakness. This could be because as a main rule, premature births take place in large maternity units, and such questions may therefore be of less relevance for the small units.
There is no generally agreed definition of what should be considered late and early umbilical cord clamping. In our questionnaire we defined early clamping as taking place within 30 seconds and late clamping if it was undertaken after one minute or later. No respondents used the free-text field to report umbilical cord clamping after 30 – 60 seconds, but we cannot exclude the possibility that some follow this routine.
A strength of our study is its high response rate. We therefore believe that the responses represent a real variation in medical practice with regard to a procedure which is undertaken approximately 60 000 times annually in the Norwegian health services.