Recombinant erythropoietin for the treatment of iron deficiency anemia in pregnancy: A systematic review

BACKGROUND

Treatment options for severe, refractory iron deficiency anemia are limited in pregnancy.

OBJECTIVE

To review the available literature on the use of recombinant erythropoietin in the treatment of iron deficiency anemia in pregnancy.

SEARCH STRATEGY

An electronic search of seven databases from inception to March 2022 was performed using a combination of keywords.

SELECTION CRITERIA

We included all randomized controlled or observational studies of pregnant patients with iron deficiency anemia who received recombinant erythropoietin or control. The primary outcome was a change in hematologic parameters (hemoglobin or hematocrit) after treatment. Studies were appraised using the criteria outlined in the Cochrane Handbook for Systematic Reviews of Interventions.

DATA COLLECTION AND ANALYSIS

Data were summarized using narrative synthesis and descriptive statistics as appropriate. This study was registered with PROSPERO, CRD42022313328.

MAIN RESULTS

Of 234 studies screened, five studies met the inclusion criteria and had sufficient data for analysis (n = 103 recombinant erythropoietin and n = 104 controls). All patients in the intervention group received iron supplementation (intravenous or oral) in addition to recombinant erythropoietin. All patients in the control group received iron supplementation (intravenous or oral) alone. As the result of variance between studies in inclusion criteria, the timing of repeat blood draws, and data reporting, a meta-analysis could not be performed. Three studies found that serial recombinant erythropoietin combined with iron supplementation was more effective at raising hematologic laboratory parameters (hemoglobin or hematocrit) than iron alone. One study reported no difference in hemoglobin or hematocrit levels between groups at day 28. However, patients in this study only received one dose of recombinant erythropoietin, whereas those in the other studies received serial doses. Another study also found no difference in hemoglobin levels by day 28, but patients in the recombinant erythropoietin group had lower hemoglobin levels at baseline and a more rapid rise in hemoglobin than iron alone. This is demonstrated by a more significant rise in hemoglobin at day 11 in the recombinant erythropoietin group than in the control group.

CONCLUSIONS

Serial recombinant erythropoietin administration and iron supplementation may be more effective at treating refractory iron deficiency anemia in pregnancy than iron supplementation alone.

Iron Sucrose: A Wealth of Experience in Treating Iron Deficiency

Iron deficiency and iron-deficiency anemia are associated with increased morbidity and mortality in a wide range of conditions. In many patient populations, this can be treated effectively with oral iron supplementation; but in patients who are unable to take or who do not respond to oral iron therapy, intravenous iron administration is recommended. Furthermore, in certain conditions, such as end-stage kidney disease, chronic heart failure, and inflammatory bowel disease, intravenous iron administration has become first-line treatment. One of the first available intravenous iron preparations is iron sucrose (Venofer®), a nanomedicine that has been used clinically since 1949. Treatment with iron sucrose is particularly beneficial owing to its ability to rapidly increase hemoglobin, ferritin, and transferrin saturation levels, with an acceptable safety profile. Recently, important new data relating to the use of iron sucrose, including the findings from the landmark PIVOTAL trial in patients with end-stage kidney disease, have been reported. Several years ago, a number of iron sucrose similars became available, although there have been concerns about the clinical appropriateness of substituting the original iron sucrose with an iron sucrose similar because of differences in efficacy and safety. This is a result of the complex and unique physicochemical properties of nanomedicines such as iron sucrose, which make copying the molecule difficult and problematic. In this review, we summarize the evidence accumulated during 70 years of clinical experience with iron sucrose in terms of efficacy, safety, and cost-effectiveness.

Iron deficiency in gynecology and obstetrics: clinical implications and management

Iron deficiency is the commonest cause of anemia during pregnancy; however, its prevalence is highly determined by nutritional and socioeconomic status. Oral iron is the frontline therapy, but is often poorly tolerated. Awareness of the available intravenous formulations is essential for management. Before delivery, risk factors such as multiparity and heavy uterine bleeding increase the prevalence of iron deficiency and should be motivation for early diagnosis and treatment. Neonates born with iron deficiency have a statistically significant increment in both cognitive and behavioral abnormalities that persist after repletion, highlighting the need for heightened awareness of the diagnosis. A smartphone application providing information on nutrition and treatment is provided. New formulations of intravenous iron with carbohydrate cores, which bind elemental iron more tightly, minimize the release of labile free iron to allow complete replacement doses of intravenous iron in 15 to 60 minutes, facilitating and simplifying care.

Treatment of Anemia of Chronic Disease with True Iron Deficiency in Pregnancy

Objective

We assess and compare the efficacy of anemia treatment in pregnant women with anemia of chronic disease with true iron deficiency and in women with iron deficiency anemia.

Study Design

Fifty patients with moderate anemia (hemoglobin 8.0–9.9 g/dl) and iron deficiency (ferritin < 15 μg/l) were treated in the Anemia Clinic at the Department of Obstetrics.

Results

All patients showed stimulation of erythropoiesis as evidenced by an increase in reticulocyte count at day eight of therapy and showed an increase in hemoglobin and hematocrit at the end of therapy (p < 0.001). The target hemoglobin (≥10.5 g/dl) was achieved in 45/50 women (90%). 12 patients showed anemia of chronic disease with true iron deficiency (12/50; 24%). Seven women (7/12; 59%) with anemia of chronic disease and iron deficiency responded well to anemia treatment. 50% of women with anemia of chronic disease and iron deficiency (3/6) responded well to intravenous iron, and 67% (4/6) responded well to the combination of intravenous iron and recombinant human erythropoietin.

Conclusion

Because of frequent true iron deficiency in pregnant women with anemia of chronic disease, anemia of chronic disease in pregnancy is often falsely diagnosed as iron deficiency anemia.

A best practice position statement on pregnancy in chronic kidney disease: the Italian Study Group on Kidney and Pregnancy

Pregnancy is increasingly undertaken in patients with chronic kidney disease (CKD) and, conversely, CKD is increasingly diagnosed in pregnancy: up to 3 % of pregnancies are estimated to be complicated by CKD. The heterogeneity of CKD (accounting for stage, hypertension and proteinuria) and the rarity of several kidney diseases make risk assessment difficult and therapeutic strategies are often based upon scattered experiences and small series. In this setting, the aim of this position statement of the Kidney and Pregnancy Study Group of the Italian Society of Nephrology is to review the literature, and discuss the experience in the clinical management of CKD in pregnancy. CKD is associated with an increased risk for adverse pregnancy-related outcomes since its early stage, also in the absence of hypertension and proteinuria, thus supporting the need for a multidisciplinary follow-up in all CKD patients. CKD stage, hypertension and proteinuria are interrelated, but they are also independent risk factors for adverse pregnancy-related outcomes. Among the different kidney diseases, patients with glomerulonephritis and immunologic diseases are at higher risk of developing or increasing proteinuria and hypertension, a picture often difficult to differentiate from preeclampsia. The risk is higher in active immunologic diseases, and in those cases that are detected or flare up during pregnancy. Referral to tertiary care centres for multidisciplinary follow-up and tailored approaches are warranted. The risk of maternal death is, almost exclusively, reported in systemic lupus erythematosus and vasculitis, which share with diabetic nephropathy an increased risk for perinatal death of the babies. Conversely, patients with kidney malformation, autosomal-dominant polycystic kidney disease, stone disease, and previous upper urinary tract infections are at higher risk for urinary tract infections, in turn associated with prematurity. No risk for malformations other than those related to familiar urinary tract malformations is reported in CKD patients, with the possible exception of diabetic nephropathy. Risks of worsening of the renal function are differently reported, but are higher in advanced CKD. Strict follow-up is needed, also to identify the best balance between maternal and foetal risks. The need for further multicentre studies is underlined.

Diagnosis and treatment of iron deficiency anemia during pregnancy and the postpartum period: Iron deficiency anemia working group consensus report

According to the World Health Organization (WHO), anemia is the most common disease, affecting >1.5 billion people worldwide. Furthermore, iron deficiency anemia (IDA) accounts for 50% of cases of anemia. IDA is common during pregnancy and the postpartum period, and can lead to serious maternal and fetal complications. The aim of this report was to present the experiences of a multidisciplinary expert group, and to establish reference guidelines for the optimal diagnosis and treatment of IDA during pregnancy and the postpartum period. Studies and guidelines on the diagnosis and treatment of IDA published in Turkish and international journals were reviewed. Conclusive recommendations were made by an expert panel aiming for a scientific consensus. Measurement of serum ferritin has the highest sensitivity and specificity for diagnosis of IDA unless there is a concurrent inflammatory condition. The lower threshold value for hemoglobin (Hb) in pregnant women is <11 g/dL during the 1^st and 3^rd trimesters, and <10.5 g/dL during the 2^nd trimester. In postpartum period a Hb concentration <10 g/dL indicates clinically significant anemia. Oral iron therapy is given as the first-line treatment for IDA. Although current data are limited, intravenous (IV) iron therapy is an alternative therapeutic option in patients who do not respond to oral iron therapy, have adverse reactions, do not comply with oral iron treatment, have a very low Hb concentration, and require rapid iron repletion. IV iron preparations can be safely used for the treatment of IDA during pregnancy and the postpartum period, and are more beneficial than oral iron preparations in specific indications.

Iron Deficiency Anemia in Pregnancy

Anemia is a common problem in obstetrics and perinatal care. Any hemoglobin below 10.5 g/dL can be regarded as true anemia regardless of gestational age. Reasons for anemia in pregnancy are mainly nutritional deficiencies, parasitic and bacterial diseases, and inborn red blood cell disorders such as thalassemias. The main cause of anemia in obstetrics is iron deficiency, which has a worldwide prevalence between estimated 20%-80% and consists of a primarily female population. Stages of iron deficiency are depletion of iron stores, iron-deficient erythropoiesis without anemia, and iron deficiency anemia, the most pronounced form of iron deficiency. Pregnancy anemia can be aggravated by various conditions such as uterine or placental bleedings, gastrointestinal bleedings, and peripartum blood loss. In addition to the general consequences of anemia, there are specific risks during pregnancy for the mother and the fetus such as intrauterine growth retardation, prematurity, feto-placental miss ratio, and higher risk for peripartum blood transfusion. Besides the importance of prophylaxis of iron deficiency, the main therapy options for the treatment of pregnancy anemia are oral iron and intravenous iron preparations.

Iron sucrose - characteristics, efficacy and regulatory aspects of an established treatment of iron deficiency and iron-deficiency anemia in a broad range of therapeutic areas

INTRODUCTION

Iron is a key element in the transport and utilization of oxygen and a variety of metabolic pathways. Iron deficiency is a major cause of anemia and can be associated with fatigue, impaired physical function and reduced quality of life. Administration of oral or intravenous (i.v.) iron is the recommended treatment for iron-deficiency anemia (IDA) in different therapeutic areas.

AREAS COVERED

This article provides an overview of studies that evaluated i.v. iron sucrose for anemia and iron status management, either alone or in combination with erythropoiesis-stimulating agents, across various diseases and conditions.

EXPERT OPINION

Iron sucrose is an established, effective and well-tolerated treatment of IDA in patients with acute or chronic conditions such as chronic kidney disease, inflammatory bowel disease, pregnancy (second and third trimester), postpartum period, heavy menstrual bleeding and cancer who need rapid iron supply and in whom oral iron preparations are ineffective or not tolerated. Available data on patient blood management warrant further studies on preoperative iron treatment. First experience with iron sucrose follow-on products raises questions about their therapeutic equivalence without comparative clinical data in newly diagnosed patients or patients on existing chronic treatment.

Placenta accreta, increta, and percreta

Placenta accreta is an abnormal adherence of the placenta to the uterine wall that can lead to significant maternal morbidity and mortality. The incidence of placenta accreta has increased 13-fold since the early 1900s and directly correlates with the increasing cesarean delivery rate. The prenatal diagnosis of placenta accreta by ultrasound along with risk factors including placenta previa and prior cesarean delivery can aid in delivery planning and improved outcomes. Referral to a tertiary care center and the use of a multidisciplinary care team is recommended.

Antiblastic treatment of haematological malignancies during pregnancy: a crucial decision

Antiblastic treatment of hematological malignancies during pregnancy poses a number of issues related to the curability of the maternal disease, the need of a prompt treatment and the potential toxicity of chemotherapy for the fetus. Here we report the results of a systematic literature search about the management of the most frequent hematological malignancies that may occur during pregnancy, focusing on specific issues related to gestational age at diagnosis, fetal toxicity and efficacy on the maternal side. The standard approach in non-pregnant women is illustrated as reference.

Is intravenous iron sucrose the treatment of choice for pregnant anemic women?

Anemia during pregnancy remains an important public health problem in developing countries like India. Anemia is the direct cause of 12-15% of maternal deaths. Iron deficiency is the commonest cause for anemia in the Indian subcontinent. Several preventive and therapeutic approaches are in practice. The available routes of iron supplementation are oral and intravenous. In spite of oral iron being least invasive, cheap and safe, the ineffectiveness of oral iron due to dietary inhibitors and poor compliance are well known. Intravenous iron sucrose can be a promising therapy for moderate to severely anemic pregnant women and has been in practice for quite some time in private and public health practices. In this article, we report the current evidence on the safety and efficacy of intravenous iron sucrose in anemic pregnant women on hematological and clinical outcomes. Though the evidence on its efficacy in improving hemoglobin and serum ferritin is convincing, its effect on maternal and fetal outcomes are unclear. This is primarily due to lack of well-designed and larger studies powered to detect difference in clinical outcomes. Hence, there is a need to gather evidence from a well-designed large randomized clinical trial conducted in a developing country. The results of such a study would feed into the national policy and would form the basis to frame guidelines for management of anemia in developing countries.

Gynaecological cancers in pregnancy

Cervical and ovarian cancers are the most common gynaecological cancers diagnosed during pregnancy. In early-stage cervical cancer during the first and at the beginning of the second trimester, the two main considerations for management of the patient are the tumour size (and stage) and nodal staging. MRI and laparoscopic lymphadenectomy are useful for clinicians planning a potentially conservative approach. The management of patients with locally advanced cervical disease is controversial and should be discussed on a case-by-case basis according to the tumour size, radiological findings, the term of pregnancy, and the patient's wishes. Different histological types of malignant ovarian diseases arise during pregnancy and their management depends on the diagnosis (histological subtypes, tumour differentiation, and nodal status), the tumour stage, and the trimester of the pregnancy. In patients with peritoneal spread or high-risk early-stage disease, neoadjuvant chemotherapy with pregnancy preservation could be appropriate.

Treatments for iron-deficiency anaemia in pregnancy

BACKGROUND

Iron deficiency, the most common cause of anaemia in pregnancy worldwide, can be mild, moderate or severe. Severe anaemia can have very serious consequences for mothers and babies, but there is controversy about whether treating mild or moderate anaemia provides more benefit than harm.

OBJECTIVES

To assess the effects of different treatments for anaemia in pregnancy attributed to iron deficiency (defined as haemoglobin less than 11 g/dL or other equivalent parameters) on maternal and neonatal morbidity and mortality.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (7 June 2011), CENTRAL (2011, Issue 5), PubMed (1966 to June 2011), the International Clinical Trials Registry Platform (ICTRP) (2 May 2011), Health Technology Assessment Program (HTA) (2 May 2011) and LATINREC (Colombia) (2 May 2011).

SELECTION CRITERIA

Randomised controlled trials comparing treatments for anaemia in pregnancy attributed to iron deficiency.

DATA COLLECTION AND ANALYSIS

We identified 23 trials, involving 3.198 women. We assessed their risk of bias. Three further studies identified are awaiting classification.

MAIN RESULTS

Many of the trials were from low-income countries; they were generally small and frequently methodologically poor. They covered a very wide range of differing drugs, doses and routes of administration, making it difficult to pool data. Oral iron in pregnancy showed a reduction in the incidence of anaemia (risk ratio 0.38, 95% confidence interval 0.26 to 0.55, one trial, 125 women) and better haematological indices than placebo (two trials). It was not possible to assess the effects of treatment by severity of anaemia. A trend was found between dose and reported adverse effects. Most trials reported no clinically relevant outcomes nor adverse effects. Although the intramuscular and intravenous routes produced better haematological indices in women than the oral route, no clinical outcomes were assessed and there were insufficient data on adverse effects, for example, on venous thrombosis and severe allergic reactions. Daily low-dose iron supplements may be effective at treating anaemia in pregnancy with less gastrointestinal side effects compared with higher doses.

AUTHORS' CONCLUSIONS

Despite the high incidence and burden of disease associated with this condition, there is a paucity of good quality trials assessing clinical maternal and neonatal effects of iron administration in women with anaemia. Daily oral iron treatment improves haematological indices but causes frequent gastrointestinal adverse effects. Parenteral (intramuscular and intravenous) iron enhances haematological response, compared with oral iron, but there are concerns about possible important adverse effects (for intravenous treatment venous thrombosis and allergic reactions and for intramuscular treatment important pain, discolouration and allergic reactions). Large, good quality trials, assessing clinical outcomes (including adverse effects) as well as the effects of treatment by severity of anaemia are required.

[Iron deficiency anemia and pregnancy. Prevention and treatment]

OBJECTIVE

To assess the effectiveness and the safety of prevention and treatment of iron deficiency anemia during pregnancy.

METHODS

French and English publications were searched using PubMed and Cochrane library.

RESULTS

Early screening of iron deficiency by systematic examination and blood analysis seemed essential. Maternal and perinatal complications were correlated to the severity and to the mode of appearance of anemia. Systematic intakes of iron supplements seemed not to be recommended. In case of anemia during pregnancy, iron supplementation was not associated with a significant reduction in substantive maternal and neonatal outcomes. Oral iron supplementation increased blood parameters but exposed to digestive side effects. Women who received parenteral supplementation were more likely to have better hematological response but also severe potential side effects during pregnancy and in post-partum. The maternal tolerance of anemia motivated the choice between parenteral supplementation and blood transfusion.

CONCLUSION

Large and methodologically strong trials are necessary to evaluate the effects of iron supplementation on maternal health and pregnancy outcomes.