Anaemia is a significant public health concern, affecting about two billion people worldwide, amongst which 56 million are pregnant women.^1,2 Globally, anaemia has been estimated to affect about 800 million children and women. Adolescent girls and women are at a higher risk because of menstruation and the high demand for metabolism during pregnancy.³ About 42.0% of pregnant women are affected by anaemia worldwide.⁴ In Southeast Asia, the prevalence of anaemia amongst pregnant women is 48.0% and anaemia in pregnancy causes half of the global maternal deaths. India contributes to 80% of these deaths.^5,6 South America has the lowest prevalence of 24.1%.⁶ In Africa, studies have found an anaemia prevalence of 57.1% amongst pregnant women.² Previous studies conducted in Tanzania have shown a varying prevalence of anaemia amongst pregnant women, ranging from 18.0% to 68.0%.⁷ The overall prevalence of anaemia amongst pregnant women was 41.0% in Ethiopia and 45.0% in Ghana.^8,9 Although there is limited data for Southern Africa, a study in South Africa found a prevalence of 42.7%.¹⁰ There is no record of previous studies on anaemia in pregnancy in Eswatini. According to the World Health Organization (WHO), anaemia amongst pregnant women is a significant health problem in low-income countries (LICs).¹¹ The WHO has defined anaemia in pregnancy as haemoglobin levels of less than 11 g/dL.^5,12 The different haemoglobin levels for each anaemia class during pregnancy are 10.0 g/dL – 10.9 g/dL for mild, 7 g/dL – 9.9 g/dL for moderate and less than 7 g/dL for severe anaemia.¹³ In addition, sub-Saharan Africa (SSA) has an estimated prevalence of 56.0%, compared with the 22.0% of high-income countries.^14,15

In LICs, anaemia in pregnancy significantly contributes to maternal and infant morbidity and mortality.¹⁶ Anaemia in pregnancy is considered a risk factor for the poor pregnancy outcome, resulting in life-threatening complications for both mother and foetus.^12,14 Foetal consequences include stillbirths, low weight, intrauterine growth restriction, premature babies, perinatal mortality and neonatal sepsis.^17,18 In late pregnancy, anaemia results in poor foetal iron stores, which can irreversibly affect the brain and neurotransmitters in the foetus and postnatal babies, leading to developmental disorders.¹⁹ Effects of anaemia during pregnancy may be related to its severity, for example, mild anaemia may not affect the current pregnancy but may reduce maternal iron stores and affect subsequent pregnancies.⁷ In addition, anaemic pregnant women are more prone to many complications, including decreased work productivity, increased risk of cardiac diseases, preterm labour and delivery, postpartum haemorrhage, impaired immune function and maternal mortality.^7,11 Anaemia during pregnancy has been estimated to account for 23% of the indirect causes of maternal deaths in developing countries.^6,19

Moreover, several factors have been identified as contributing factors of anaemia amongst pregnant women. Iron deficiency is the most common cause; it is usually accompanied by a deficiency of other nutrients.^8,13 Around 40% of women begin their pregnancy with decreased iron stores, which becomes insufficient to meet the increased iron needs during pregnancy.^2,20 Other factors include physiological haemodilution, underlying inflammatory conditions and malnutrition, leading to insufficient vitamins, proteins, iron and iodine.^11,13 In addition, in SSA, infections such as malaria, helminths and human immunodeficiency virus (HIV) also contribute to anaemia in pregnancy.^13,21 Despite the broader scope of the problem, little research data have been explored about the severity of anaemia at antenatal care clinic (ANC) in this study area; hence, there is a need to identify and treat anaemia to avoid its complications in pregnancy.^1,11 Furthermore, assessing the different factors contributing to anaemia in pregnancy is essential for effective anaemia management during pregnancy and provides the necessary information for planning and policymaking.^7,9

This is the first study assessing prevalence and risk factors for anaemia in pregnancy in the Kingdom of Eswatini. The prevalence of anaemia in this study (43.1%) shows that this is a public health concern. According to the WHO, anaemia is a public health problem if its prevalence is greater than or equal to 5.0%, and a severe problem if prevalence is greater than or equal to 40.0%.^7,15 Other researchers have reported the prevalence of anaemia during pregnancy, ranging from 32.0% to 62.2%.¹⁵ In SSA countries, prevalence of anaemia in pregnancy has been reported to be 57.0%.²³ Similar prevalence of anaemia was found in South East Asian countries (48.0%),⁶ Northern Tanzania (47.0%),¹⁵ Kenya (40.0%),²⁴ and South Africa (43.0%).⁴ Lower anaemia prevalence has been reported in Lesotho (33.2%),²⁵ Botswana (34.0%),²⁶ Ethiopia (36.6%) and Nigeria (37.6%).¹⁷ Higher prevalence of anaemia was reported in Eastern Kenya (57.0%),²⁷ Pakistan (56.4%),²⁸ and North East India (60.0%).⁶ The variations in prevalence of anaemia may be due to different causes of anaemia, dietary differences, population differences, study design and differences in methodology used in determining haemoglobin levels.^24,28 Regarding the differences in severity, the similar prevalence of anaemia was reported in Northern Ghana⁸ and Egypt,²⁹ where the mild and moderate anaemia cases were similar.

In this study, anaemia prevalence was highest in the age group 15–19 years (53.3%). A study in Northern Ghana reported similar findings, where anaemia prevalence in the age group 20 years and below was 51.5% compared with 47.8% in those older than 35 years.³⁰ Another study in Nigerian reported the highest anaemia prevalence amongst participants in the age group of 20 years and below.¹⁷ High prevalence of anaemia in younger ages might have been because of the lack of awareness, poor knowledge of antenatal services and failure to seek prenatal care early and take care of themselves during pregnancy.^5,17 However, there was a contrasting report from Ethiopia, where the highest anaemia prevalence was reported amongst participants of the age group 30–39 years.⁹ Another study in India reported the highest prevalence of anaemia in the age group 20–29 years.⁶ This might have been because of increased body weakness, multiple pregnancies, labour and being subjected to other illnesses leading to a predisposition to anaemia as age advances.^9,27

This study reported anaemia prevalence higher amongst women living in the urban area (48.9%) than women living in rural areas (35.6%). Consistent findings were reported in a study in Southern Nigeria.¹⁷ This is contrary to other studies in India and Northern Ethiopia, where anaemia prevalence was high amongst pregnant women living in rural areas compared with those living in urban areas.^6,31 This may be because of limited access to health facilities and limited resources for adequate and proper nutrition during pregnancy.^16,31,32 Based on the finding of this study, anaemia prevalence was highest in women with a monthly household income of less than $343.00 (44.9%). These findings are consistent with a study in Ethiopia, where women from lower socio-economic classes had a higher prevalence of anaemia than those from higher socio-economic classes.^2,18 The women from lower socio-economic status were perceived as unable to afford good quality food.^2,12 The highest anaemia prevalence was amongst the unemployed, pregnant women (44.4%). A study in Nigeria also reported similar findings, where it stated that the participants had little or no income to buy the right food required to prevent anaemia.¹⁷ One study in Kenya showed contrasting results of the high prevalence of anaemia amongst the employed participants.²⁷ They stated that the employed participants had no time to rest or attend ANC clinics compared with housewives.²⁷

The highest anaemia prevalence was reported amongst participants who were in the third trimester of their pregnancy. Similar findings were reported in Egypt²⁹ and Ghana.⁸ This might have been due to reducing iron stores as a result of increasing demand for iron for both the mother and foetus, as pregnancy progress.^2,18 In pregnant women, late detection of anaemia increases the risk of eclampsia and post-partum haemorrhage.⁵ In the foetus and neonates, anaemia increases the risk of developmental delays, premature and stillbirths.^1,5 There was a significant association between gestational age at first ANC and anaemia in pregnancy. In this study, those in the third trimester were about six-fold more likely to be anaemic than those in the second trimester. These findings are similar to a study reported in Ethiopia, where women in the second and third trimesters were 3.1 and 3.7 times more likely to develop anaemia than those in the first trimester.² During pregnancy, physiological haemodilution occurs as the pregnancy progresses, worsening anaemia in the third trimester.¹⁶

The prevalence of anaemia declined from gravida one (45.8%) to gravida two (42.1%), increased in gravida three (43.4%) and declined again in gravida four or more (39.0%). There was no association between gravidity and anaemia. A study in Tanzania reported the same pattern of results, although there was no association between gravidity and anaemia¹⁵ and in Uganda, there was no evidence of increased risk of anaemia in multigravida as compared with primigravida.³³ However, a study in India indicated a positive correlation between gravidity and anaemia and the same study showed an increase in anaemia prevalence as gravidity increased, which is not consistent with this study.⁵ In this study, anaemia prevalence declined from para zero (45.8%) to para two (38.8%), increased in para three (46.6%) and declined again in para four or more (34.5%). There was no association between parity and anaemia. In China, a retrospective study by Lin et al. showed no association between multiparity and anaemia.³² However, a study in India showed an association between anaemia and parity, where women who had given birth two or more times had the highest anaemia prevalence.⁵ This was consistent with another study in South Africa, where anaemia prevalence in primipara women was 32.7% and multi- and grand-para, 36.8%.⁴ The initial decrease in anaemia prevalence as gravidity and parity increased might have been because the small sample sizes of participants as gravidity and parity increased.³⁴

This study showed that being on chronic medication was a risk for developing anaemia in pregnancy. Similarly, a study from India observed an association between anaemic pregnant women with a chronic illness in pregnancy or the recent past.¹¹ Also, this study found that HIV was significantly associated with anaemia in pregnancy. In Uganda, a study showed similar findings, where pregnant women infected with HIV were twice more likely to have anaemia than their HIV-negative counterparts.³⁵ The HIV infection is associated with lower serum folic acid and ferritin levels, and the use of antiretroviral drugs, especially Zidovudine, is associated with anaemia.^4,35 In HIV-infected individuals, there is a relative deficiency of iron in the body; therefore, the body cannot effectively use iron to generate new blood cells.^11,36

The limitations of this study were that this was a hospital-based study, so results could only be generalised to women attending ANC and not all pregnant women in the population. In addition, the study design was cross-sectional, so it was impossible to identify and establish cause and effect relationships. Nevertheless, the findings shed some light on anaemia in pregnancy and the associated risks, and they provide a platform for further studies. The study’s strengths were that the diagnosis of anaemia was based on laboratory analysis and did not depend on clinical assessment. This is the first study on prevalence and risks associated with anaemia in pregnancy, and it gives perspective to the burden of anaemia in Eswatini. It also serves as a benchmark for further research into the role of other factors that may contribute to understanding anaemia in pregnancy.

The findings of this study shed some light on anaemia in pregnancy and the associated risks, and the recommendations are as follows:

Based on our study findings, the following future areas of research are recommended:

The results of this study highlight prevalence and associated risk factors for anaemia amongst pregnant women attending ANC in three hospitals in Eswatini and indicate potential factors for interference to alleviate the anaemia burden in Eswatini. The findings show that anaemia amongst pregnant women attending ANC in three hospitals in Eswatini, is associated with the place of living and gestational age at first ANC, amongst others. Also, this study concludes that the prevalence of anaemia is high amongst pregnant women in Eswatini. Furthermore, the study has provided essential information about anaemia and associated risk factors that can contribute to policy development and prevention strategies. Finally, the findings provide epidemiological knowledge about the distribution of anaemia. This is crucial to guide the continuous awareness and health education on the implication of anaemia and the importance of prevention and reducing the risk of anaemia in pregnancy.