Frequent blood donation and offspring birth weight—a next‐generation association?

Abstract

BACKGROUND The prevalence of iron depletion is high among premenopausal women who donate blood frequently. Studies in nondonor populations indicate that iron deficiency anemia is associated with an increased risk of low birth weight. This prompts concerns that iron deficiency induced by frequent blood donation might impair subsequent fetal development. STUDY DESIGN AND METHODS The aim of this study was to assess whether prepregnancy donation intensity affects the birth weight of singletons born at term (gestational week 38 or later) to nulliparous female donors in Denmark. We identified 293,897 first live singleton births to Danish women between 1997 and 2012 with complete information on gestational age, birth weight, child sex, parental age, maternal smoking status during pregnancy, and parental education length and annual income. Linear regression analysis was applied, with birth weight as outcome, number of donations within the 3 years before pregnancy as the explanatory variable, and confounding variables as described. RESULTS Birth weight among children of low‐intensity donors (n = 22,120) was 12.6 g (95% confidence interval, 6.7–18.6) higher than nondonors (n = 268,253) after controlling for the above‐mentioned factors. The higher birth weight among low‐intensity donors can be explained by the healthy donor effect. In fully adjusted analyses, birth weight among children of high‐intensity donors (n = 3,524) was 20.2 g (95% confidence interval, 5.1–35.3 g) lower compared with low‐intensity donors. This reduced birth weight among high‐intensity donors compared to low‐intensity donors may reflect blood donation–induced iron deficiency. CONCLUSIONS Our results show that high prepregnancy donation intensity is inversely associated with birth weight of singletons born at term to nulliparous women.

Frequent blood donation and offspring scholastic attainment: an assessment of long‐term consequences of prenatal iron deficiency

“…This has prompted concern that female donors may inadvertently put their unborn offspring at a similar risk. Recently, we reported a small but statistically significant negative association between number of donations before pregnancy and birth weight (a decrease of 10.5 g [95% CI, 3.3–17.7] per annual donation in a 3‐year period); however, this was not the case in an earlier study from Canada . Despite these conflicting results, iron deficiency due to donation may still be a risk factor for fetal neurological development due to iron being prioritized for RBC production over other iron‐dependent tissues as evaluated in an animal study .…”

“…We interpret the latter finding to result from residual confounding due to incomplete adjustment for socioeconomic and lifestyle factors known to differ between donors and nondonors. 21 We have adjusted for two of the most widely used socioeconomic factors; however, other not available lifestyle factors such as diet, exercise, sleep, and stress could differ between donors and nondonors. Most notably, the effect of donor status on offspring grade scores decreased markedly when covariates were added to the model.…”

2018 European Conference on Donor Health and Management

“…Among high‐frequency donors (with more than nine donations in the past 3 years), they found iron deficiency (ferritin below 15 ng mL −1 ) in 9, 39 and 22% of men, pre‐menopausal women and post‐menopausal women, respectively (Rigas et al, ). Iron deficiency can have clinical significance beyond anaemia, for example, in the study, it is associated with depression, Restless Legs Syndrome and low birth weight (Rigas et al, ). The use of the Copenhagen algorithm, using ferritin measurements to advice on iron supplementation, was explained.…”

DBDS Genomic Cohort, a prospective and comprehensive resource for integrative and temporal analysis of genetic, environmental and lifestyle factors affecting health of blood donors

“…The registries include the National Patient Registry containing all hospital-registered diagnoses since 197518 as well as other specialised registries, for example, the Danish Medical Birth Register, the Danish Register of Causes of Death and Statistics Denmark monitoring, for example, socioeconomic data. We have already used the DBDS cohort in epidemiological studies assessing, for example, the mortality19 of donors and the effect of blood donation on offspring birth weight 20…”