Effect of early and delayed umbilical cord clamping on placental transfusion in two-step delivery: a randomised clinical trial

Abstract

Abstract Objective To investigate the effect of ‘two-step’ delivery and early (ECC) or delayed cord clamping (DCC) on placental transfusion in term infants.Methods Randomised clinical trial (NCT04459442). 90 infants were randomised to ECC (at 1 minute) or DCC (at 3 minutes) before two-step delivery wherein 83 (39 with ECC and 44 with DCC) received the allocated intervention. The primary outcome was the placental transfusion defined by ∆ haematocrit (Hct) from cord blood at birth and capillary heel blood at 48 h of age, accounting for body weight decrease, with the power estimate based on haematocrit (Hct) levels, in ECC and DCC neonate groups. The secondary outcomes were the contemporary readings of arterial cord blood gases, lactate, and glucose.Results It was found that Hct levels, comparable at birth between neonates who underwent ECC or DCC (49.501 ± 0.909 vs 48.764 ± 0.824, p 0.551), were significantly increased at 48 hours of age in the DCC group (50.778 ± 1.102 vs 55.051 ± 0.979, p 0.0051) representing a significantly higher ∆ Hct (1.278 ± 5.29 vs 6.287 ± 0.998, p 0.011) despite a comparable body weight decrease, all pointing to a higher placental transfusion in the DCC group, presenting with an acid–base and metabolic equilibrium.Conclusion In term infants born by ’two-step’ delivery, DCC results in a higher blood volume in the newborn and facilitates the maternal–placental–foetal exchange of circulating compounds, without potentially detrimental neonatal outcomes.