Providing additional placental blood to the preterm baby by either delaying cord clamping for 30 to 120 seconds, rather than early clamping, seems to be associated with less need for transfusion, better circulatory stability, less intraventricular haemorrhage (all grades) and lower risk for necrotising enterocolitis. However, there were insufficient data for reliable conclusions about the comparative effects on any of the primary outcomes for this review.
A randomised controlled trial of delayed cord clamping in very low birth weight preterm infants.
This study was carried out to assess the feasibility of late cord clamping of 45 s in preterm infants delivered mainly by caesarean section and the effects on postpartal adaptation and anaemia of prematurity. Prior to delivery, 40 infants of < 33 gestational weeks were randomised to either 20 s or 45 s of late cord clamping. After the first shoulder was delivered, oxytocin was given intravenously to the mother in order to enhance placento-fetal transfusion while the infant was held below the level of the placenta. The 20 infants in group 1 (20 s) had a mean birth weight of 1070 g and a mean gestational age of 29 + 4/7 weeks versus 1190 g and 30 weeks in group 2 (45 s). On day 42 of life there were ten infants without transfusions in group 2 versus three in group 1 (P < 0.05). Out of the 20 infants in group 1, 19 and 15/19 in group 2 were delivered by caesarean section. There were no significant differences in Apgar scores, temperature on admission, heart rate, blood pressure and requirements for artificial ventilation.
                Delayed cord clamping of 45 s is feasible and safe in preterm infants below 33 weeks of gestation. It is possible to perform the procedure at caesarean section deliveries and it should be performed whenever possible. It reduces the need for packed red cell transfusions during the first 6 weeks of life.