[The effects of iron stores and growth of delayed umbilical cord clamp timing on term breastfed infants at 4 months].

OBJECTIVE: To explore whether delayed umbilical cord clamp timing of newborn can improve iron stores of infant period and growth and development. METHODS: Mother-infant pairs were randomly assigned to early clamping (94 cases, < 15 s after delivery) and delayed clamping (64 cases, 1 min after delivery) by draw lots, and followed up until 4 months postpartum. Infant hematological status, iron status, the level of growth and development of infants after 4 months were measured respectively. Transcutaneous bilirubin at the third day after delivery was also measured. RESULTS: At 4 month age, the median of serum ferritin and mean of corpuscular volume value in delayed group were 87.30 µg/L and (79.62 ± 4.13) fl, significantly higher than the values in early group (64.3 µg/L, (78.21 ± 4.38) fl), respectively (Z = -2.36, t = 2.23, both P values < 0.05). The hematocrit value was (33.59 ± 2.48)%, higher than that in early group (32.76 ± 2.69)% (t = 1.95, P = 0.05). There was no statistically significant difference at other iron nutrition indicators and infants' weight and body length at 4 month (P > 0.05). Under the different cut-off values (hemoglobin (Hb) < 105 g/L and Hb < 110 g/L, respectively), the prevalence of anemia in delay and early clamping group were 6.25% (4/64), 21.86% (14/64), and 12.77% (12/94), 34.04% (32/94), respectively (both P values > 0.05). CONCLUSION: Delayed umbilical cord clamp timing until 1 min can improve iron stores of breastfed infants at 4 month; there is no significant adverse effects to growth.