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Effect of delayed vs early umbilical cord clamping on iron status and neurodevelopment at age 12 months: a randomized
Ola Andersson1, Magnus Domellöf2, Dan Andersson3
1Department of Pediatrics, Hospital of Halland, Halmstad, Sweden2Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden.
Insights
Delayed cord clamping (DCC) did not significantly impact infant iron status or neurodevelopment at 12 months. However, findings suggest sex-specific effects on neurodevelopment, warranting further investigation.
Area of Science:
- Neonatal care
- Pediatric neurodevelopment
- Iron metabolism
Background:
- Iron deficiency in infancy can negatively affect neurodevelopment.
- Delayed cord clamping (DCC) is a strategy to prevent early iron deficiency.
- Long-term infant outcomes related to umbilical cord clamping duration are not well-established.
Purpose of the Study:
- To compare the effects of DCC versus early cord clamping (ECC) on infant iron status and neurodevelopment at 12 months.
- To assess infant iron biomarkers and neurodevelopmental outcomes in a European cohort.
Main Methods:
- A randomized clinical trial involving 382 full-term infants in Sweden.
- Infants were randomized to DCC (≥180 seconds) or ECC (≤10 seconds).
- Iron status and neurodevelopment (Ages and Stages Questionnaire) were evaluated at 12 months.
Main Results:
- No significant differences in iron status or neurodevelopment were observed between DCC and ECC groups at 12 months.
- Infant sex and early breastfeeding were predictors of iron status and neurodevelopment.
- An interaction analysis indicated potential sex-specific effects of DCC on neurodevelopment (P=.04).
Conclusions:
- Delayed cord clamping did not alter iron status or neurodevelopment in healthy term infants at 12 months.
- The study may have been underpowered to detect minor neurodevelopmental effects.
- Further research is needed to explore the biological mechanisms behind observed sex-specific effects of DCC on infant development.
Importance:
Prevention of iron deficiency in infancy may promote neurodevelopment. Delayed cord clamping (DCC) can prevent iron deficiency during the first 6 months of life. However, no data are available on long-term effects on infant outcomes in relation to time for umbilical cord clamping.
Objective:
To investigate effects of DCC, as compared with early cord clamping (ECC), on infant iron status and neurodevelopment at age 12 months in a European setting.
Design, Setting, And Participants:
Randomized clinical trial of 382 full-term infants born after a low-risk pregnancy at a Swedish county hospital. Follow-up at 12 months included evaluation of iron status (ferritin level, transferrin saturation, transferrin receptor level, reticulocyte hemoglobin level, and mean cell volume) and parental assessment of neurodevelopment by the Ages and Stages Questionnaire, second edition (ASQ).
Interventions:
Infants were randomized to DCC (≥180 seconds after delivery) or ECC (≤10 seconds after delivery).
Main Outcomes And Measures:
The main outcome was iron status at age 12 months; the secondary outcome was ASQ score.
Results:
In total, 347 of 382 infants (90.8%) were assessed. The DCC and ECC groups did not differ in iron status (mean ferritin level, 35.4 vs 33.6 ng/mL, respectively; P = .40) or neurodevelopment (mean ASQ total score, 229.6 vs 233.1, respectively; P = .42) at age 12 months. Predictors of ferritin levels were infant sex and ferritin in umbilical cord blood. Predictors of ASQ score were infant sex and breastfeeding within 1 hour after birth. For both outcomes, being a boy was associated with lower results. Interaction analysis showed that DCC was associated with an ASQ score 5 points higher among boys (mean [SD] score, 229 [43] for DCC vs 224 [39] for ECC) but 12 points lower among girls (mean [SD] score, 230 [39] for DCC vs 242 [36] for ECC), out of a maximum of 300 points (P = .04 for the interaction term).
Conclusions And Relevance:
Delayed cord clamping did not affect iron status or neurodevelopment at age 12 months in a selected population of healthy term-born infants. However, it may not be possible to demonstrate minor effects on neurodevelopment with the size of the study population and the chosen method for assessment. The current data indicate that sex may influence the effects on infant development after DCC in different directions. The magnitude and biological reason for this finding remain to be investigated. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01245296.
