Women with Perioperative Anemia Experience Higher Transfusion Rates

Credit: ResearchGate

Females with perioperative anemia experience higher transfusion rates than their male peers, according to a new study.

Because of iron deficiencies, females are more likely to have anemia to begin with. Blood requires iron to carry oxygen through the body, but when women lose a lot of blood on their period, they also lose iron. Pregnancy and childbirth can also lead to iron deficiencies.² Taking iron supplements and food with iron like dark-green leafy vegetables, iron-fortified cereals or bread, brown rice, pulses and beans, nuts and seeds, meat, fish, and tofu, eggs, and dried fruit like dried apricots, prunes, and raisins can help fight iron deficiencies.²

As for iron deficiency anemia, this is when a lack of iron results in a reduction of red blood cells. Iron is what produces red blood cells, and if you lack iron, your body will receive less oxygen than normal. Iron deficiency anemia marks as the most common type of anemia, although other types of anemia can be caused by the lack of vitamin E or folate in the body.

A team of investigators led by by Sumedha Arya, MD, a hematologist and transfusion fellow at the University of Toronto, and colleagues conducted a retrospective study of the Ontario Transfusion Coordinators Network (ONTraC) database from 2018 – 2022 to see if the level of transfusion rates varied by sex.

“By optimizing erythropoiesis, patient blood management (PBM) programs can reduce transfusions, lower mortality, and provide cost-effective care,” the investigators wrote.

ONTraC complied data from 25 Ontario hospitals and kept track of Ontario’s provincial blood use, which was about 400,000 units per year. The data included 17,700 patients, and nearly half (47%) of the patients in the database were female (n = 8376). The study defined anemia as hemoglobin (Hb) <130 g/L, even though the level of anemia can differ by sex.

The investigators collected data on 60 consecutive patients per year at each hospital site. Patients could be going through elective isolated coronary artery bypass graft surgery (CABG), open heart valve replacement, CABG plus valve replacement, single knee arthroplasty, and single hip arthroplasty.

Over half (68%) of the procedures were knee and hip arthroplasties. Throughout the years, females tended to have a significantly lower preoperative, nadir, and discharge Hb than males. Arya and colleagues also found females’ transfusion rates were significantly higher, especially in cardiac surgery. The transfusion rates were consistent over the years, and thus COVID-19 did not affect the numbers.

The team noted that the study did not fully address that females experience greater perioperative anemia because of iron deficiency.

“Given the well described adverse effects of perioperative anemia and transfusion on morbidity and mortality, this highlights an area of health inequity that warrants further attention,” the investigators wrote.

The study’s findings mirrored the findings of a 2016 cohort study that which primarily examined gender disparities in red blood cell transfusion. The investigators in the prior trial found that the absolute red blood cells (RBC) loss was lower in women than in men in all surgical categories, but the RBC loss was higher in women then in men in the CABG surgery (52.8% vs 47.8%, P <.0001).³

“The prevalence of preoperative anemia in the present study was similar in both genders, so this factor cannot explain the higher transfusion rates in women,” the investigators of the earlier study wrote. “The fact that the prevalence of anemia among women was similar to that among men might be attributable to the higher age of the patients included in the study, because the higher prevalence of low hemoglobin values observed in younger women disappears with increasing age.”

References

1. ^{Arya, S, Howell, A, Vernich L, et al. Let’s Talk About Sex: Females Experience Greater Perioperative Anemia and Higher Transfusion Rates in Major Elective Surgery.” Wiley. 2023. https://doi.org/10.1111/trf.55_17554}
2. ^{Reduce Iron Deficiency in Females Aged 12 to 49 Years—NWS-17. U.S. Department of Health and Human Services. https://health.gov/healthypeople/objectives-and-data/browse-objectives/nutrition-and-healthy-eating/reduce-iron-deficiency-females-aged-12-49-years-nws-17#:~:text=Women%20are%20more%20likely%20than,help%20women%20get%20enough%20iron. Assessed October 20, 2023.}
3. ^{Gombotz H, Schreier G, Neubauer S, Kastner P, Hofmann A. Gender disparities in red blood cell transfusion in elective surgery: a post hoc multicentre cohort study. BMJ Open. 2016;6(12):e012210. Published 2016 Dec 13. doi:10.1136/bmjopen-2016-012210}