The association between frequency of blood donation and the occurrence of low birthweight, preterm delivery, and stillbirth: a retrospective cohort study

Eligibility Considerations for Female Whole Blood Donors: Hemoglobin Levels and Iron Status in a Nationally Representative Population

Blood collection from minority populations improves the transfusion support of patients with sickle cell disease and thalassemia, but efforts are challenged by high deferral rates for hemoglobin (Hb) eligibility thresholds. This study sought to evaluate hemoglobin and iron status of a representative US female population to assess the suitability of 12.0 g/dL as minimum hemoglobin. Data were extracted from the National Health and Nutrition Examination Surveys (NHANES), 1999-2010. A national sample designed to reflect potential female blood donors (weight ≥110 lbs, not pregnant, no infectious marker reactivity, and no blood donation in past year) aged 16 to 49 years was analyzed for Hb and serum ferritin (SF) measures by race/ethnicity (N = 6937). Mean Hb and SF and the prevalence of iron deficiency ([ID] SF<12 ng/mL and SF<26 ng/mL) and low Hb (<12.5 g/dL and <12.0 g/dL) were estimated. Multivariable modified Poisson regression compared the prevalence for ID or low Hb at each cutoff by race/ethnicity. Mean SF values were higher and ID prevalence was lower in Non-Hispanic (NH) White (SF = 45.3 ng/mL, SF<12 ng/mL = 8.2%) than NH Black (SF = 39.6 ng/mL, SF<12 ng/mL = 14.2%) and Hispanic (SF = 36.5 ng/mL, SF<12 ng/mL = 12.7%) females. Compared to NH White females (13.7 g/dL), mean Hb was lower in NH Black (12.6 g/dL) and Hispanic females (13.4 g/dL). The percentage with Hb<12.5 g/dL was >4 times greater in NH Black (39.1%) and >2 times greater in Hispanic females (16.5%) compared to NH White (8.6%). Within 0.5 g/dL incremental categories of Hb, NH Black had higher mean SF levels and lower prevalence of SF<12 ng/mL or <26 ng/mL compared to NH White and Hispanic females. At Hb of 12.0 to 12.4g/dL, NH Black females had better measures of iron status (SF = 39.1 ng/mL, %SF<12 ng/mL = 12.0%) than NH White (SF = 33.6 ng/mL, %SF<12 ng/mL=15.8%) and Hispanic (SF = 30.4 ng/mL, %SF<12 ng/mL=15.5%) females whose Hb was 12.5 to 12.9 g/dL. Adjusting for age and Hb, the prevalence ratio for low SF was significantly lower in NH Black compared to NH White females at both SF<26 ng/mL (adjusted prevalence ratio [aPR] = 0.83, 95%CI = 0.76-0.92) and SF<12 ng/mL (aPR = 0.66, 95%CI = 0.52-0.83). NH Black females with Hb 12.0 to 12.4g/dL have better iron stores than NH White and Hispanic females whose Hb is 12.5 to 12.9 g/dL. The distribution of Hb and iron may support the safe collection of blood for female donors below the current Hb eligibility requirement of 12.5 g/dL.

Iron status of blood donors

PURPOSE OF REVIEW

This review examines recent research on the prevalence and importance of iron deficiency in blood donors, and on efforts to mitigate it.

RECENT FINDINGS

Premenopausal females, teenagers, and high-frequency donors are at the highest risk for donation-induced iron deficiency, in both high-resource and low-resource settings. The physiology relating iron stores to hemoglobin levels and low hemoglobin deferral is well elucidated in blood donor populations, yet the clinical effects attributable to iron loss in the absence of anemia are challenging to identify. Expanded adoption of ferritin testing is improving donor management but may cause decreases in the blood supply from temporary donor loss. The potential for personalized donor management is emerging with development of computational models that predict individual interdonation intervals that aim to optimize blood collected from each donor while minimizing low hemoglobin deferrals.

SUMMARY

Measures to reduce iron deficiency are available that can be deployed on a standardized or, increasingly, personalized basis. Blood centers, regulators, and donors should continue to evaluate different tactics for addressing this problem, to obtain a balanced approach that is optimal for maintaining adequate collections while safeguarding donor health.

The influence of blood donation before pregnancy on neonatal birth weight

Objective

To evaluate the effect of blood donation before pregnancy on neonatal birth weight.

Methods

A total of 14996 women with singleton pregnancies at full-term in Ningbo Medical Center Lihuili Hospital and Ningbo Women’s and Children’s Hospital from November 2019 to November 2020 were enrolled in this study. Detailed records of whole blood donation before pregnancy were obtained through Alipay software. The records were classified into three groups: nondonors, low-frequency donors and high-frequency donors according to the total numbers of blood donations in the 3-year period before pregnancy. The demographics and clinical information of the enrolled participants and their fetuses were collected from electronic medical records (EMRs). The effect of blood donations in the 3-year period before pregnancy on neonatal birth weight was analyzed.

Results

There was no significant difference in neonatal birth weight among the three groups (P = 0.373). In line with this, there was no association between the number of blood donations in the 3-year period before pregnancy and neonatal birth weight (β = 14.5; 95% confidence interval [CI]: -3.9, 31.4; P = 0.094) in the bootstrapped multivariate linear regression analysis models, adjusted for maternal age, number of pregnancies, number of deliveries, gestational age, mode of delivery, years of education and blood type in pregnant women. Compared to the nondonors, the risk of fetal macrosomia was higher in both low-frequency donors and all donors (OR: 1.539, 95% CI: 1.058, 2.134, P = 0.016; OR: 1.454, 95% CI: 1.033, 1.952, P = 0.021, respectively), in the bootstrapped binary logistic regression analysis models after adjusting for the variables mentioned above.

Conclusion

Our study showed that maternal blood donation in the 3-year period before pregnancy may not lead to a reduction in neonatal birth weight, but may be associated with the incidence of fetal macrosomia.

The Effect of Parenteral or Oral Iron Supplementation on Fatigue, Sleep, Quality of Life and Restless Legs Syndrome in Iron-Deficient Blood Donors: A Secondary Analysis of the IronWoMan RCT

Background: Besides anemia, iron deficiency may cause more subtle symptoms, including the restless legs syndrome (RLS), the chronic fatigue syndrome (CFS) or sleeping disorders. Objective: The aim of this pre-planned secondary analysis of the IronWoMan randomized controlled trial (RCT) was to compare the frequency and severity of symptoms associated with iron deficiency before and after (intravenous or oral) iron supplementation in iron deficient blood donors. Methods/Design: Prospective, randomized, controlled, single-centre trial. (ClinicalTrials.gov: NCT01787526). Setting: Tertiary care center in Graz, Austria. Participants: 176 (138 female and 38 male) whole-blood and platelet apheresis donors aged ≥ 18 and ≤ 65 years with iron deficiency (ferritin ≤ 30ng/mL at the time of blood donation). Interventions: Intravenous iron (1 g ferric carboxymaltose, n = 86) or oral iron supplementation (10 g iron fumarate, 100 capsules, n = 90). Measurements: Clinical symptoms were evaluated by a survey before iron therapy (visit 0, V0) and after 8–12 weeks (visit 1, V1), including questions about symptoms of restless legs syndrome (RLS), chronic fatigue syndrome (CFS), sleeping disorders, quality of life and symptoms like headaches, dyspnoea, dizziness, palpitations, pica and trophic changes in fingernails or hair. Results: We found a significant improvement in the severity of symptoms for RLS, fatigue and sleep quality (p < 0.001). Furthermore, a significant decrease in headaches, dyspnoea, dizziness and palpitations was reported (p < 0.05). There was no difference between the type of iron supplementation (intravenous versus oral) and clinical outcome data. Conclusion: Iron supplementation in iron-deficient blood donors may be an effective strategy to improve symptoms related to iron deficiency and the wellbeing of blood donors.

Evaluating the Clinical Effect of Female Blood Donors of Child-Bearing Age on Maternal and Neonatal Outcomes: A Cohort Study

Iron deficiency is a global problem in women of child-bearing age and is associated with adverse maternal and newborn outcomes. Repeated blood donations deplete iron stores and decrease hemoglobin levels. However, the clinical impact of iatrogenic iron deficiency on mothers and neonates due to blood donation is uncertain. The objective of this study was to assess the association between repeated blood donations in female donors of child-bearing age and the associated risk of adverse maternal and neonatal outcomes. We undertook an observational cohort study of all women who delivered a live or stillborn infant in Ontario, Canada, between 1 January 2010 and 31 March 2012 using birth record data from the Better Outcomes Registry & Network, Canadian Blood Services, and the Institute of Clinical Evaluative Sciences. Only a woman's first pregnancy within the study time frame was included for analysis. We excluded women <18 years or >50 years of age at the time of delivery and multiple birth pregnancies. Data on all female donors who made whole blood donations between 1 January 2007 and 31 March 2012 were obtained from Canadian Blood Services. The primary newborn outcome was diagnosis of a small-for-gestational-age neonate (less than 10th centile). Secondary outcomes were preterm birth, stillbirth, APGAR <4 at 5 minutes, cord pH <7, neonatal death, maternal transfusion, infection, preeclampsia, gestational hypertension, gestational diabetes, placental abruption, and maternal death. Regression models evaluated the effect of repeated donation and the time interval between donations and conception on neonatal and maternal outcomes while adjusting for important clinical and demographic risk factors. A total of 260 037 women delivered live or stillborn singleton infants between 1 January 2010 and 31 March 2012. A total of 7919 (3.0%) women were blood donors, with a mean of 2.43 ± 2.10 lifetime donations. Mean maternal age at the time of delivery for nondonors and donors was 30.30 ± 5.38 and 29.74 ± 4.94 years, respectively. Small for gestational age occurred in 23 706 (9.4%) of neonates born to nondonors and 526 (6.6%) of neonates born to donors. There was a reduction in the risk of small for gestational age with increasing number of lifetime donations (adjusted odds ratio 0.89 [0.86-0.92] per additional donation). For the prespecified secondary outcomes, we observed a reduction in the risk of low birth weight (adjusted odds ratio 0.95 [0.91-0.98] per additional donation). There was no association with other secondary neonatal or maternal outcomes except for maternal hypertension. Proximity of donation to conception had no effect on risk of a small-for-gestational age neonate. Our data suggest that there is no increased risk of deleterious neonatal and maternal outcomes associated with repeated blood donations prior to pregnancy. Although possibly a result of a healthy donor effect, our findings are reassuring to female donors and their children as well as to clinicians and blood system stakeholders seeking to inform policy decisions.

Iron Depletion in Adult and Teenage Blood Donors: Prevalence, Clinical Impact, and Options for Mitigation

Iron depletion is a known risk for adult blood donors, but recent studies indicate the prevalence of iron depletion is higher in teenage blood donors. Teenage donors account for more than 10% of the blood collected in the United States and are important for maintaining component availability. Evidence of harm from iron depletion has not been demonstrated, but the area would benefit from further scientific inquiry. Options to protect against iron depletion exist, but each has limitations including cost, logistics, and potential negative impact on blood supply. Blood centers should communicate with donors and make efforts to mitigate these risks.

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

BACKGROUND

Due to physiological demands, children and premenopausal women are at risk of developing iron deficiency. In premenopausal women, the risk may be further increased by repeated whole blood donations. Short-term consequences of iron deficiency in infancy include impaired cognitive development and lower IQ scores. This prompts concern that maternal iron deficiency before or during pregnancy may have long-term consequences for the offspring, for example, by affecting scholastic attainment. The aim of this study was to evaluate if prepregnancy donation intensity is associated with offspring scholastic attainment measured as grade averages in standardized national written examinations in Denmark.

STUDY DESIGN AND METHODS

By using the Danish personal identification number as key, we obtained information on donation intensity before pregnancy, school grade, year of graduation, age of the students, students' sex, and parental length of education and income from various nationwide registers. Linear regression analyses were performed, with grade average as outcome and maternal donation status as explanatory variable (nondonor, n = 177,078; low-frequency donor, n = 4995 [one to five donations in the 3 years before pregnancy]; high-frequency donor, n = 414 [six or more donations in the 3 years before pregnancy), and further adjusted for the covariates listed above.

RESULTS

Adjusted normalized (mean, 0; standard deviation [SD], 1) test scores were statistically significantly higher for children of active female donors compared with children of nondonors (SD, 0.104; 95% confidence interval, 0.079-0.129). We observed no differences in scholastic attainment between children of low-frequency donors and high-frequency donors.

CONCLUSION

Prepregnancy donation intensity, as a proxy of iron stores, is not associated with subsequent offspring scholastic attainment.

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

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.