Timing of umbilical cord clamping and neonatal jaundice in singleton term pregnancy

Delayed cord clamping was not adopted widely in China because of the potential effect of neonatal hyperbilirubinemia, jaundice and polycythemia, and the optimal cord clamping time remained controversial.

To assess the effect of delayed cord clamping versus early cord clamping on neonatal jaundice for term infants.

This retrospective study included 1981 mother-infant pairs, who were assigned to early cord clamping groups (n = 1005) and delayed cord clamping group (n = 949). The delayed cord clamping included three subgroups (30-60 s, 61-90 s, 91-120 s). The main outcomes were transcutaneous bilirubin levels at 0 to 4 days of age, the rate of jaundice requiring phototherapy, the neonatal hematological status at 1 to 3 days after birth.

Compared with the early cord clamping group, the neonatal transcutaneous bilirubin level did not differ and the neonatal hematological status (hemoglobin and hematocrit levels) were improved in combined and three subgroups of delayed cord clamping group. Increasing the duration of cord clamping from 90 s to 120 s did not result in further increases in hemoglobin and hematocrit levels but led to a trend towards a higher risk of neonatal jaundice requiring phototherapy and neonatal polycythemia.

Delayed cord clamping for <90 s in healthy term infants may not only improve the early hematological status of newborns but also avoid excessive neonatal jaundice requiring phototherapy.