Elective caesarean: does delay in cord clamping for 30 s ensure sufficient iron stores at 4 months of age? A historical cohort control study

Objective: To compare iron stores in infants born after elective caesarean section (CS) and a 30 s delay of umbilical cord clamping with those born vaginally after early (<= 10 s) or delayed (>= 180 s) cord clamping. Design: Prospective observational study with historical control. Setting: Swedish county hospital. Population: 64 infants born after elective CS were compared with a historical control of 166 early clamped and 168 delayed clamped after vaginal birth. Methods: Blood and iron status were measured in blood samples collected at birth, 48-96 hours after birth, 4 and 12 months of age. Primary and secondary outcome measures: Ferritin at 4 months of age was the primary outcome, second outcome measures were other indicators of iron status, and haemoglobin, at 4 and 12 months of age, as well as respiratory distress at 1 and 6 hours after birth. Results: At 4 months infants born by elective CS had better iron status than those born vaginally subjected to early cord clamping, shown by higher adjusted mean difference of ferritin concentration (39 mu g/L (95% CI 10 to 60)) and mean cell volume (1.8 fL (95% CI 0.6 to 3.0)); and lower levels of transferrin receptors (-0.39 mg/L (95% CI -0.69 to -0.08)). No differences were seen between infants born after elective CS and delayed clamped vaginally born infants at 4 months. No differences were found between groups at 12 months of age. Conclusions: Waiting to clamp the umbilical cord for 30 s after elective CS results in higher iron stores at 4 months of age compared with early cord clamping after vaginal birth, and seems to ensure iron status comparable with those achieved after 180 s delayed cord clamping after vaginal birth.