Effects of delayed cord clamping at different time intervals in late preterm and term neonates: a randomized controlled trial

Extended period of ventilation before delayed cord clamping augments left-to-right shunting and decreases systemic perfusion at birth in preterm lambs

Previous studies have suggested that an extended period of ventilation before delayed cord clamping (DCC) augments birth-related rises in pulmonary arterial (PA) blood flow. However, it is unknown whether this greater rise in PA flow is accompanied by increases in left ventricular (LV) output and systemic arterial perfusion or whether it reflects enhanced left-to-right shunting across the ductus arteriosus and/or foramen ovale (FO), with decreased systemic arterial perfusion. Using an established preterm lamb birth transition model, this study compared the effect of a short (∼40 s, n = 11), moderate (∼2 min, n = 11) or extended (∼5 min, n = 12) period of initial mechanical lung ventilation before DCC on flow probe-derived perinatal changes in PA flow, LV output, total systemic arterial blood flow, ductal shunting and FO shunting. The LV output was relatively stable during initial ventilation but increased after DCC, with similar responses in all groups. Systemic arterial flow patterns displayed only minor differences during brief and moderate periods of initial ventilation and were similar after DCC. However, an increase in PA flow was augmented with an extended initial ventilation (P < 0.001), owing to an earlier onset of left-to-right ductal and FO shunting (P < 0.001), and was accompanied by a pronounced reduction in total systemic arterial flow (P = 0.005) that persisted for 4 min after DCC (P ≤ 0.039). These findings suggest that, owing to increased left-to-right shunting and a greater reduction in systemic arterial perfusion, an extended period of ventilation before DCC does not result in greater perinatal circulatory benefits than shorter periods of initial ventilation in the birth transition. KEY POINTS: Previous studies suggest that an extended period of initial ventilation before delayed cord clamping (DCC) augments birth-related rises in pulmonary arterial (PA) blood flow. It is unknown whether this greater rise in PA flow is accompanied by an increased left ventricular output and systemic arterial perfusion or whether it reflects enhanced left-to-right shunting across the ductus arteriosus and/or foramen ovale, with decreased systemic arterial perfusion. Anaesthetized preterm fetal lambs instrumented with central arterial flow probes underwent a brief (∼40 s), moderate (∼2 min) or extended (∼5 min) period of ventilation before DCC. Perinatal changes in left ventricular output were similar in all groups, but extended initial ventilation augmented both perinatal increases in PA flow, owing to earlier onset and greater left-to-right ductal and foramen ovale shunting, and perinatal reductions in total systemic arterial perfusion. Extended ventilation before DCC does not confer a greater perinatal circulatory benefit than shorter periods of initial ventilation.

Comparison of Three Methods of Umbilical Cord Management in Late Preterm and Term Newborns on Hemoglobin and Ferritin Levels at Six Weeks of Age: A Randomized Controlled Trial

BACKGROUND

Umbilical cord milking (UCM) and delayed cord clamping (DCC) are strategies that improve the hemodynamic condition of the newborn and also increase the storage of iron. This study aimed to compare the effects of DCC with or without milking in late preterm and term neonates at different time intervals after birth (60, 120, and 180 seconds) on hematological and hemodynamic parameters in neonates at six weeks of age.

MATERIALS AND METHODS

In this double-arm, parallel-group, triple-blind, and active-controlled trial, all 150 eligible neonates were randomized with allocation concealment into three groups: Group A (DCC with UCM at 60 seconds), Group B (DCC with UCM at 120 seconds), and Group C (only DCC for 180 seconds). Hemodynamic parameters were recorded and compared during the first 48 hours, and hematological parameters were compared at six weeks of age.

RESULTS

At six weeks, a significant difference in hemoglobin levels was noted between Groups A, B, and C (p<0.001). The difference in serum ferritin values at six weeks was also statistically significant in comparisons across all three groups (p=0.003). Regarding secondary outcomes examined, hemodynamic parameters and the incidence of neonatal hyperbilirubinemia were found to be comparable at 48 hours after birth.

CONCLUSION

DCC followed by UCM at 120 seconds and DCC till 180 seconds proves superior to DCC with UCM at 60 seconds in preserving elevated hemoglobin levels and iron stores in neonates at six weeks of age. DCC for 180 seconds yielded comparable results, followed by UCM at 120 seconds. All three methods are considered safe and effective without compromising the neonate's hemodynamics.

Delayed umbilical cord clamping in elective and nonelective term Cesarean delivery

BACKGROUND

Delayed cord clamping (DCC) is recommended for preterm and term neonates, regardless of delivery mode. After impression of increased maternal blood loss following DCC implementation during Cesarean delivery (CD) concerns arose about maternal safety, particularly in term CDs.

MATERIALS AND METHODS

We conducted a retrospective cohort study by reviewing birth records from our tertiary hospital in Kuopio, Finland including 914 women with singleton term CD and recorded estimated blood loss. Early cord clamping (ECC) occurred from January 2016 to December 2019, while DCC (30-60 s) from January 2020 to December 2020. We evaluated maternal and neonatal outcomes for ECC vs. DCC and assessed severe postpartum hemorrhage (PPH) (≥1500 ml) and its potential clinical risk factors.

RESULTS

In total, 914 women were included (DCC N = 152; ECC N = 762). Estimated mean maternal blood loss showed no significant difference between DCC and ECC groups (697 ml vs. 750 ml, p < 0.96). Severe PPH was less frequent in the DCC group (4.6% vs. 10.5 %, p < 0.024). Neonatal outcomes were similar between groups. Multivariable analysis revealed that women with placenta previa (OR 5.63, p < 0.001), macrosomic neonate (OR 2.75, p < 0.001), and intrapartum infection (OR 2.00, p < 0.057) had an increased risk for severe PPH. Earlier CD was associated with less severe PPH (OR 0.36, p < 0.001).

CONCLUSIONS

DCC (30-60 s) during term CD did not increase maternal blood loss in singleton pregnancies and demonstrated no short-term adverse effects on neonates. Our findings support the general practice of DCC during both elective and nonelective term CD.