Iron deficiency anemia is the most common nutritional deficiency worldwide and remains a significant public health problem, particularly among pregnant women. According to the World Health Organization, approximately 40% of pregnant women globally are affected by anemia, with iron deficiency accounting for nearly half of these cases. The burden is especially high in developing countries due to poor nutritional intake, repeated pregnancies, and limited access to healthcare services [1]. Pregnancy is associated with increased iron requirements to support fetal growth, placental development, and expansion of maternal red cell mass. The total iron requirement during pregnancy is estimated to be around 1000 mg, which is often difficult to meet through diet alone [2]. Inadequate iron intake or absorption leads to depletion of iron stores, resulting in reduced hemoglobin synthesis and subsequent anemia. Iron deficiency anemia during pregnancy has been associated with adverse maternal and fetal outcomes, including preterm delivery, low birth weight, and increased maternal morbidity [3]. Fatigue is one of the most common and debilitating symptoms experienced during pregnancy, often attributed to physiological changes. However, anemia significantly exacerbates fatigue by impairing oxygen transport to tissues. Musculoskeletal fatigue, characterized by muscle weakness, body aches, and decreased endurance, is an important but frequently under-recognized manifestation of iron deficiency anemia. This type of fatigue can negatively affect daily functioning, reduce physical activity, and impair overall quality of life in pregnant women [4]. The pathophysiological basis of musculoskeletal fatigue in iron deficiency anemia involves reduced oxygen-carrying capacity of blood and impaired oxidative metabolism in skeletal muscles. Iron is a critical component of hemoglobin, myoglobin, and several mitochondrial enzymes involved in energy production. Deficiency of iron leads to decreased aerobic capacity and early onset of muscle fatigue due to accumulation of lactic acid and reduced ATP generation [5]. Additionally, iron deficiency may directly affect muscle function independent of anemia, further contributing to fatigue symptoms. Several studies have highlighted the association between anemia and generalized fatigue; however, limited research has specifically focused on musculoskeletal fatigue in pregnant women. Given that pregnancy itself predisposes women to musculoskeletal discomfort due to hormonal and biomechanical changes, the added burden of anemia may significantly worsen these symptoms [6]. Understanding this association is crucial for early identification and targeted management of affected individuals. Despite routine antenatal screening for anemia, musculoskeletal fatigue is often overlooked in clinical practice. Recognizing fatigue as a potential indicator of underlying iron deficiency may help in improving maternal care and quality of life. Therefore, this study aims to evaluate the association between iron deficiency anemia and musculoskeletal fatigue among pregnant women.

Study Design and Setting This study was a retrospective observational study conducted in the Department of Obstetrics and Gynecology in collaboration with the department of Orthopaedics of a tertiary care teaching hospital. The study utilized existing medical records of pregnant women attending antenatal outpatient and inpatient services. Study Duration The study was carried out over a period of 6 months Study Population The study population included all pregnant women who attended the antenatal clinic or were admitted during the study period and whose medical records were available for review. Sample Size A total of 200 pregnant women fulfilling the inclusion criteria were included in the study. The sample size was determined based on the availability of complete medical records during the study period. Inclusion Criteria • Pregnant women of any gestational age (all trimesters) • Availability of complete hemoglobin records • Documentation of clinical symptoms, particularly musculoskeletal fatigue • Records containing basic demographic details Exclusion Criteria • Pregnant women with chronic systemic illnesses (e.g., renal disease, cardiac disease, thyroid disorders) • Patients with non-iron deficiency causes of anemia (e.g., hemolytic anemia, aplastic anemia, vitamin B12 deficiency where documented) • Cases with incomplete or missing medical records • Women with acute infections or inflammatory conditions that could influence fatigue Data Collection Procedure Data were collected retrospectively from hospital medical records and antenatal registers. A structured data collection format was used to extract relevant information, including: • Demographic details: age, gravidity, parity • Obstetric details: gestational age, trimester • Laboratory parameters: o Hemoglobin levels (g/dL) o Serum ferritin levels (where available) • Clinical features: o Presence or absence of musculoskeletal fatigue o Symptoms such as muscle weakness, generalized body aches, and reduced endurance Operational Definitions Iron Deficiency Anemia Anemia was defined according to WHO criteria: • Mild anemia: 10–10.9 g/dL • Moderate anemia: 7–9.9 g/dL • Severe anemia: <7 g/dL Iron deficiency anemia was considered in patients with low hemoglobin levels along with supportive clinical findings and/or low serum ferritin levels (where available). Musculoskeletal Fatigue Musculoskeletal fatigue was defined as the presence of documented complaints in medical records such as: • Generalized muscle weakness • Body aches or musculoskeletal pain • Easy fatigability or reduced physical endurance Data Processing and Statistical Analysis Data were entered into Microsoft Excel and analyzed using Statistical Package for Social Sciences (SPSS) version 20.0. The following statistical methods were applied: • Descriptive statistics: o Mean and standard deviation (SD) for continuous variables o Frequencies and percentages for categorical variables • Inferential statistics: o Independent t-test was used to compare mean hemoglobin levels between groups (with and without fatigue) o Chi-square test was used to assess the association between anemia and musculoskeletal fatigue o p-value < 0.05 was considered statistically significant Ethical Considerations: The study was conducted after obtaining approval from the Institutional Ethics Committee

A total of 200 pregnant women were included in the study. The mean age was 25.6 ± 3.8 years. Primigravida constituted 55% of the study population. Table 1: Demographic Characteristics of Study Population Variable n (%) / Mean ± SD Age (years) 25.6 ± 3.8 Gravidity ─ Primigravida 110 (55%) ─ Multigravida 90 (45%) The prevalence of anemia among pregnant women was 58%, indicating a high burden in the study population. Table 2: Prevalence of Iron Deficiency Anemia Category Number Percentage Anemic 116 58% Non-anemic 84 42% Musculoskeletal fatigue was significantly more common among anemic women compared to non-anemic women. The association was statistically highly significant. Table 3: Association Between Anemia and Musculoskeletal Fatigue Group Fatigue Present Fatigue Absent Total p-value Anemic (n=116) 84 (72%) 32 (28%) 116 < 0.001 Non-anemic (n=84) 32 (38%) 52 (62%) 84 Mean hemoglobin levels were significantly lower in women with fatigue compared to those without fatigue. Table 4: Comparison of Mean Hemoglobin Levels Group Mean Hb (g/dL) SD p-value With fatigue 8.9 ±1.2 < 0.001 Without fatigue 10.8 ±1.1 There was a statistically significant trend showing increased fatigue with increasing severity of anemia. Table 5: Severity of Anemia vs Musculoskeletal Fatigue Severity Total Cases Fatigue Present Percentage p-value Mild 40 22 55% < 0.001 Moderate 50 38 76% Severe 26 24 92%

Iron deficiency anemia (IDA) remains a major public health concern among pregnant women, particularly in developing countries. In the present study, the prevalence of anemia was found to be 58%, which is consistent with global estimates reported by the World Health Organization, indicating that anemia affects a substantial proportion of pregnant women worldwide [7]. The high prevalence observed in this study may be attributed to inadequate dietary intake, increased iron requirements during pregnancy, and limited awareness regarding iron supplementation. The present study demonstrated a significant association between iron deficiency anemia and musculoskeletal fatigue. Approximately 72% of anemic women reported fatigue compared to 38% of non-anemic women, with a highly significant p-value (<0.001). These findings are in agreement with earlier studies that have reported fatigue as one of the most common symptoms of anemia, significantly affecting physical performance and daily activities [8]. The pathophysiological mechanism underlying this association can be explained by the reduced oxygen-carrying capacity of blood in anemic individuals. Hemoglobin plays a critical role in oxygen transport to tissues, including skeletal muscles. Reduced hemoglobin levels lead to impaired oxygen delivery, resulting in decreased aerobic metabolism and increased reliance on anaerobic pathways. This causes early muscle fatigue, accumulation of lactic acid, and reduced endurance [9]. Additionally, iron is an essential component of myoglobin and mitochondrial enzymes, and its deficiency further compromises muscle energy metabolism. The present study also found that mean hemoglobin levels were significantly lower in women experiencing musculoskeletal fatigue compared to those without fatigue. This supports the hypothesis that the severity of anemia correlates with the degree of fatigue. Similar findings were reported by Haas and Brownlie, who demonstrated that iron deficiency leads to reduced work capacity and impaired muscle function [10]. Furthermore, a dose-response relationship was observed in this study, where the prevalence of fatigue increased with the severity of anemia. Women with severe anemia showed the highest proportion of musculoskeletal fatigue (92%), followed by moderate (76%) and mild anemia (55%). This trend is consistent with previous studies suggesting that worsening anemia leads to greater functional impairment and reduced quality of life [11]. Pregnancy itself is associated with physiological and biomechanical changes that can contribute to fatigue and musculoskeletal discomfort. Hormonal influences, particularly increased levels of relaxin and progesterone, lead to ligamentous laxity and altered posture, predisposing women to muscle strain and fatigue. When combined with anemia, these effects are further exacerbated, resulting in significant impairment of daily activities [12]. Early identification and management of iron deficiency anemia through iron supplementation, dietary counseling, and regular antenatal check-ups can significantly improve maternal well-being. Addressing anemia not only reduces fatigue but also prevents adverse maternal and fetal outcomes, including preterm birth and low birth weight [9].

Iron deficiency anemia is highly prevalent among pregnant women and is significantly associated with increased musculoskeletal fatigue. Lower hemoglobin levels are linked to greater fatigue, and the severity of fatigue rises with worsening anemia. This highlights the importance of recognizing fatigue as a clinically relevant symptom during antenatal care. Early detection and appropriate management of anemia through supplementation and nutritional support can help reduce fatigue and improve maternal well-being and overall pregnancy outcomes.

1. World Health Organization. Global prevalence of anemia in 2011. Geneva: WHO; 2015. 2. Bencaiova G, Breymann C. Mild anemia and pregnancy outcome. Curr Opin Obstet Gynecol. 2014;26(6):506–511. 3. Allen LH. Anemia and iron deficiency: effects on pregnancy outcome. Am J Clin Nutr. 2000;71(5):1280S–1284S. 4. Haas JD, Brownlie T. Iron deficiency and reduced work capacity: a critical review. J Nutr. 2001;131(2):676S–690S. 5. Beard JL. Iron biology in immune function, muscle metabolism and neuronal functioning. J Nutr. 2001;131(2):568S–580S. 6. Scholl TO. Iron status during pregnancy: setting the stage for mother and infant. Am J Clin Nutr. 2005;81(5):1218S–1222S. 7. World Health Organization. Global prevalence of anemia in 2011. Geneva: WHO; 2015. 8. Bencaiova G, Breymann C. Mild anemia and pregnancy outcome. Curr Opin Obstet Gynecol. 2014;26(6):506–511. 9. Allen LH. Anemia and iron deficiency: effects on pregnancy outcome. Am J Clin Nutr. 2000;71(5):1280S–1284S. 10. Haas JD, Brownlie T. Iron deficiency and reduced work capacity: a critical review. J Nutr. 2001;131(2):676S–690S. 11. Beard JL. Iron biology in immune function, muscle metabolism and neuronal functioning. J Nutr. 2001;131(2):568S–580S. 12. Scholl TO. Iron status during pregnancy: setting the stage for mother and infant. Am J Clin Nutr. 2005;81(5):1218S–1222S.