[The application of cut-umbilical cord milking in term cesarean deliveries for preventing anemia and iron deficiency of newborns].

ABSTRACT

Objective: To anlysis the efficacy and safety of cut-umbilical cord milking (C-UCM) compared with immediate cord clamping in preventing anemia and iron deficiency among term cesarean-delivered newborns. Methods: A total of 485 pregnant women planning to deliver by cesarean section were recruited in this randomized controlled trial in Hunan Maternal and Child Health Hospital and Liuyang Maternal and Child Health Care Hospital from July 2016 to April 2019. A block randomization was conducted to evenly allocate them to the controlled group and the C-UCM group. In the controlled group, the cord was clamped within 30 seconds as routine. In the C-UCM group, the cord was first clamped at 25 cm from the newborn's navel, and then the blood in the cord was gently squeezed into the newborn's body until the cord became white and shriveled. The cord was clamped twice at 2-3 cm from the newborn's navel subsequently. Neonatal jaundice, hyperbilirubinemia and polycythemia were monitored before discharge. After the newborns discharged, their hemoglobin, red blood cell count, hematocrit (at the age of 1, 6 and 12 months) and serum ferritin (at the age of 6 and 12 months) were followed up; body length and weight were measured; and information about their feeding and iron supplementation were collected (at the age of 1, 6, 12 and 18 months). The two groups were compared by t test, Mann-Whitney U test, χ² test, or Fisher exact probability method. The hospital was set as a random item, and the mixed effects regression model was used to evaluate the effect of C-UCM on relevant indicators of cesarean-delivered newborns. Results: There were 244 women in the C-UCM group with an average age of (31.9±4.4) years, and 241 in the control group with an average age of (31.8±4.2) years (P>0.05). There was no statistically significant difference between the C-UCM group and the control group at 1, 6 and 12 months of age in hemoglobin [(123.6±14.5) vs (122.2±14.5) g/L, (115.3±9.4) vs (114.1±8.5) g/L, (115.6±9.6) vs (116.1±12.6) g/L] or anemia incidence rate [15.2% (17/112) vs 18.4% (19/103), 22.7% (34/150) vs 26.8% (44/164), 22.3% (25/112) vs 19.5% (22/113)] (all P>0.05). There was no statistically significant difference between the two groups at 6 and 12 months of age in serum ferritin [M (Q1, Q3), 39.9 (24.9, 61.8) vs 43.6 (25.2, 100.9) µg/L, 40.3 (25.4, 259.2) vs 40.3 (26.4, 167.6) µg/L)] or iron deficiency incidence rate [6.1% (5/82) vs 4.2% (3/72), 6.7% (5/75) vs 3.8% (3/80)] (all P>0.05). There were also no significant difference between the two groups in other indicators, such as the Z-score of weight-for-length, the incidence of neonatal jaundice, and the incidence of neonatal hyperbilirubinemia (all P>0.05). After adjusting for the relevant covariates, there were still no significant effects of C-UCM on these outcomes above. Conclusions: Compared to immediate cord clamping, the intervention of gently squeezing 25 cm of the cord does not significantly reduce the risk of anemia or iron deficiency in term cesarean-delivered newborns, nor does it have a significant impact on infant growth and development. Yet this intervention does not increase the risk of jaundice or hyperbilirubinemia in newborns as well.