Effects of delayed compared with early umbilical cord clamping on maternal postpartum hemorrhage and cord blood gas sampling: a randomized trial

Objective. To investigate the effect of delayed cord clamping (DCC) compared with early cord clamping (ECC) on maternal postpartum hemorrhage (PPH) and umbilical cord blood gas sampling. Design. Secondary analysis of a parallel-group, single-center, randomized controlled trial. Setting. Swedish county hospital. Population. 382 term deliveries after a low-risk pregnancy. Methods. Deliveries were randomized to DCC (>= 180 seconds, n = 193) or ECC (<= 10 seconds, n = 189). Maternal blood loss was estimated by the midwife. Samples for blood gas analysis were taken from one umbilical artery and the umbilical vein, from the pulsating unclamped cord in the DCC group and from the double-clamped cord in the ECC group. Samples were classified as valid when the arterial-venous difference was -0.02 or less for pH and 0.5 kPa or more for pCO(2). Main outcome measures. PPH and proportion of valid blood gas samples. Results. The differences between the DCC and ECC groups with regard to PPH(1.2%, p = 0.8) and severe PPH(-2.7%, p = 0.3) were small and non-significant. The proportion of valid blood gas samples was similar between theDCC (67%, n = 130) and ECC (74%, n = 139) groups, with 6% (95% confidence interval: -4%-16%, p = 0.2) fewer valid samples after DCC. Conclusions. Delayed cord clamping, compared with early, did not have a significant effect on maternal postpartum hemorrhage or on the proportion of valid blood gas samples. We conclude that delayed cord clamping is a feasible method from an obstetric perspective.