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Developmental Biology - Birth Complications

Birthing Moms Have More Transfusion Complications

Postpartum transfusions are on the rise, carrying greater risk of adverse events...

Women who receive a blood transfusion after giving birth are twice as likely to have an adverse reaction related to their procedure, such as fever, respiratory distress, or hemolysis (destruction of red blood cells), compared with non-pregnant women receiving the same care. All data according to a new study published in Blood Advances.
Women with preeclampsia, a condition marked by high blood pressure during pregnancy, were found to be at the greatest risk for problems.

This study is the first to investigate the overall risk of transfusion reactions in pregnant women. It also suggests that postpartum hemorrhages requiring blood transfusion are becoming more common.
The number of postpartum transfusions increased by 40 percent during a 20-year study period. Generally, up to 3 percent of all pregnant women receive a blood transfusion postpartum.

Although the exact reason for the increase in postpartum transfusions is not fully known, pregnant women today tend to be older, have higher body fat, more often conceive by in vitro fertilization, and are more likely to undergo cesarean delivery, have placental complications or multiple pregnancies, which are thought to be contributing factors, according to the researchers.
"Blood transfusions are on the rise among postpartum women. There seems to be something about pregnancy that makes transfusion-related adverse events and complications more likely. Based on our findings, obstetricians and clinicians need to be more aware of these potentially harmful reactions when evaluating pregnant women for blood transfusion, especially if they have preeclampsia, induced labor, or preterm delivery (before 34 weeks)."

Lars Thurn PhD, Karolinska Institutet, Stockholm, Sweden and study senior author.

This retrospective, population-based study included all women who gave birth in Stockholm County, Sweden, between 1990 and 2011. Researchers linked data from the Swedish National Birth Registry to the Stockholm Transfusion Database, which included information on blood components administered and whether a transfusion reaction occurred in women who received blood transfusions postpartum. These data were compared with the outcomes of non-pregnant women who received blood transfusions during the same period.

Of the 517,854 women studied, 12,183 (2.4 percent) received a blood transfusion. A total of 96 postpartum transfusion-related reactions were recorded, with a prevalence of 79 versus 40 occurring for every 10,000 pregnant and non-pregnant women, respectively. The risk of a transfusion-related reaction was also doubled among women diagnosed with preeclampsia compared with pregnant women who didn't have the condition.

Previous cesarean delivery heightened the risk of placental complications and bleeding in subsequent pregnancies. In this study, 26 percent of all women who received more than 10 units of blood postpartum had a previous cesarean delivery compared with 8 percent of women who had no blood transfusion postpartum. The likelihood of problems was also significantly increased when a combination of all three types of blood component (red blood cells, plasma and platelets) was administered.

Dr. Thurn: "Most blood transfusions are safe and many are life-saving, but adverse transfusion reactions and transfusion transmitted infections are a concern. In this population blood products should only be administered when necessary and when alternative options have been considered."
During pregnancy, a woman's immune system changes to accept and protect her growing fetus. Also, red cell, leukocyte, and platelet antibodies are often elevated in women who have had previous pregnancies — and are associated with a higher risk of transfusion reactions. These and other changes, including her rise in blood flow and workload on her heart, may play a role in transfusion-related complications, adds Dr. Thurn.

Thurn and his team are hopeful that this study will prompt research to understand the causes and/or risk factors associated with different types of transfusion reactions in pregnancy to help make transfusions safer.

Postpartum hemorrhages with blood transfusions are increasing in many high-resource countries. Currently, up to 3% of all women receive blood transfusion postpartum. Most blood transfusions are safe and, in many cases, are lifesaving, but there are significant concerns about adverse reactions. Pregnancy is associated with higher levels of leukocyte antibodies and has a modulating effect on the immune system. Our objective was to investigate whether blood transfusions postpartum are accompanied by an increased risk for transfusion reactions (TRs) compared with transfusions given to nonpregnant women. We included all women who gave birth in Stockholm County, Sweden between 1990 and 2011. Data from the Swedish National Birth Registry were linked to the Stockholm Transfusion Database and included information on blood components administered and whether a TR occurred in women who received blood transfusions postpartum. Background controls were nonpregnant women who received blood transfusions during the study period. The study cohort consisted of 517,854 women. Of these, 12,183 (2.4%) received a blood transfusion. We identified 96 events involving a TR postpartum, giving a prevalence of 79 per 10,000 compared with 40 per 10,000 among nonpregnant women (odds ratio, 2.0; 95% confidence interval, 1.6-2.5). Preeclampsia was the single most important risk factor for TRs (odds ratio, 2.1; 95% confidence interval, 1.7-2.6). We conclude that special care should be taken when women with preeclampsia are considered for blood transfusion postpartum, because our findings indicate that pregnancy is associated with an increased risk for TRs.

Lars Thurn, Agneta Wikman, Magnus Westgren and Pelle G. Lindqvist.

This work was supported in part by Södra Sjukvårdsregionen (grant REGSKANE-542301) (L.T.).

Authorship Contribution: L.T. designed and performed the research, collected and analyzed data, performed statistical analysis, and wrote the manuscript; A.W. designed the research, collected and analyzed data, edited the manuscript, and approved the final submitted version of the manuscript; M.W. designed the research, analyzed data, edited the manuscript, and approved the final submitted version of the manuscript; and P.G.L. designed the research, collected and analyzed data, performed statistical analysis, edited the manuscript, and approved the final submitted version of the manuscript. Conflict-of-interest disclosure: The authors declare no competing financial interests. Correspondence: Lars Thurn, Department of Obstetrics and Gynecology, Skånes Universitetssjukvård, Region Skåne, SE-221 85 Lund, Sweden; e-mail: lars.thurn@ki.se.

Blood Advances, is a peer-reviewed, online only, open access journal of the American Society of Hematology (ASH), the world's largest professional society concerned with the causes and treatment of blood disorders.

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Aug 13 2019   Fetal Timeline   Maternal Timeline   News  

Risk of transfusion reaction in Pregnant versus Non-Pregnant Women. CREDIT:
Swedish National Birth Registry, linked to the Stockholm Transfusion Database.

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