Predictors of Anemia Among Pregnant Women Attending Public Healthcare Facilities in Bengaluru, South India

Introduction

Anemia is a common nutritional deficiency and a serious public health problem. Anemia in pregnancy is defined as a hemoglobin concentration (Hb) < 110 g/L.¹ Hemoglobin concentration varies due to various factors and varying specific physiological needs. Nutritional iron deficiency is a common form of anemia; another common is folate deficiency megaloblastic anemia.² Anemia in pregnancy is mainly due to the increased nutritional requirements of the mother and fetus. Secondary causes include a lack of iron and folate supplements in the prenatal period. Other causes are deficiencies of vitamins A and B12 and parasitic infections, such as malaria and hookworm, or chronic infections like tuberculosis (TB) and human immune deficiency virus (HIV).^3-5

Globally, 40% of pregnant women are anemic.6-8 India contributes about 80% of maternal deaths due to anemia in South Asia, and the prevalence of anemia during pregnancy in India is 50.4%.^9-11 Anemia is most prevalent in low-resource settings due to cultural beliefs, lack of education, and lack of access to efficient healthcare.¹² India has taken initiatives to combat anemia among children, adolescents, and women in the reproductive age group. The government's continuous efforts have successfully reduced anemia to a marginal level, from 58% in NFHS-3 (National Family Health Survey-2005 -06) to 50.4 % in the NFHS-4 survey (2015-16).¹¹ Anemia during pregnancy leads to higher morbidity and mortality in India, and it is the second most common cause of maternal deaths.¹³ It is estimated that one in two pregnant women is anemic in India.¹⁴ and 19% of maternal deaths that occur in India are due to maternal anemia.^14,15

Anemia in pregnancy leads to poor outcomes. The adverse outcomes due to anemia include vaginal bleeding and delivery before the due date low birth weight intrauterine growth retardation, reduced neonatal iron stores, and placental problems^16-20. Apart from this, the mother may suffer due to the depleted blood reserves during delivery, which may result in consequences such as transfusions in case of significant blood loss, cardiovascular stress, the effect on mental and physical capacities, prolonged hospitalization along with decreased milk production in the puerperium.^21,22

Therefore, it is crucial to identify risk factors that contribute to the development of anemia and are associated with anemia in pregnancy. This will help to understand and make necessary modifications to the ongoing programs. Iron and folic acid supplement (IFA) with 100 mg elemental iron and 500 μg of folic acid is recommended to correct anemia during pregnancy. The supplementation is given daily for all non-anemic pregnant women for at least 100 days starting from 14-16 weeks of gestation, followed by the same dose for 100 days postpartum through the National Iron Plus Initiative.²³ Despite this, anemia is still a public health problem among pregnant mothers in India.

Anemia prevalence during pregnancy is the best indicator to assess the effectiveness of interventions focused on maternal healthcare. As per the fifth National Family Health Survey (NFHS) reports, 45.7% of pregnant women are anemic in Karnataka, and the results do not differ much from the NFHs-4 survey (45.4%).^24,14 Despite the intervention, improvement in anemia is stagnant. There is a need to investigate the correlates of anemia as the available evidence on the correlates of anemia is limited. Most previous studies were cross-sectional, and the results were constrained by temporal ambiguity. Earlier studies did not have information on detailed anthropometric assessments done prospectively, diagnosis of gestational diabetes, blood pressure assessments, and nutrition-specific assessments (intake of IFA supplementation, 24-hour dietary recall). Measurement of some variables was limited due to the lack of a standardized measure of anthropometric parameters and the quality of the blood collection process and investigation at the site. Therefore, there is a need to identify the factors contributing to anemia, which will help reform maternal health policy and health program decisions to reduce anemia and its complications on pregnant mothers and their fetuses. Our study aimed to identify predictors of anemia by validated assessments of anthropometric measurement, nutrition-specific information and obstetric history details.

Materials and Methods

Sample and data collection

Maternal Antecedents of Adiposity Studying the Transgenerational role of Hyperglycaemia and Insulin (MAASTHI) birth cohort has been established in Bengaluru. The study protocol has been published elsewhere.²⁵ The study population consisted of pregnant women with a gestational age of 14 to 32 weeks who were accessing antenatal care at a secondary hospital, Bengaluru. The health centers where recruitment was conducted included Jayanagar Hospital, Srirampura Referral Hospital, Tavarekere Primary Health Center, Magadi Road Urban Health Center, and Pantharapalya Urban Health Center.

Design and procedure

The study was nested in the MAASTHI cohort to prospectively assess the effects of glucose levels in pregnancy on the risks of adverse infant outcomes. The eligible pregnant women attending Antenatal care (ANC) care were asked to participate in the study. The inclusion criteria were being pregnant, having a gestational age of 14 to 36 weeks, and having a maternal age between 18-45 years. The purpose of the study was explained to the mothers who were enrolled after obtaining written informed consent. The data was collected from April 2016 to December 2019.

Data Collection

The information was collected on socio-demographic factors, obstetric details, smoking status, and alcohol consumption among participants and their spouses. Social support has been measured using a questionnaire developed by St. Johns Research Institute Bengaluru. The Edinburgh Postnatal Depression Scale assessed psychosocial stress.26 The scores range from 0-30, and a cut-off of 13 was taken to define depression symptoms.

Maternal anthropometry: At registration, maternal weight, height, and mid-upper arm circumference (MUAC) were measured following standard WHO guidelines. Body mass index (BMI) was classified into four groups as per their BMI according to the Asian Pacific cut-off points as follows: underweight (<18.5 kg/ m² ), normal (18.5-22.9 kg/m² ), overweight (23–24.9 kg/ m² ), and obese (≥25 kg/m² ). Although no optimal cut-off was available for pregnancy, the sum of skinfold thickness values above the 90th percentile was indicated as obesity.

Blood pressure measurement: The trained research staff recorded blood pressure (BP) using the digital OMRON BP apparatus. Blood pressure was categorized as normal (systolic BP <120 mm Hg, and diastolic BP <80 mm Hg) and elevated blood pressure (systolic BP ≥120 mm Hg and diastolic BP ≥80 mm Hg) according to the Eighth Joint National Committee (JNC) guidelines ²⁷

Laboratory analysis: All eligible pregnant women were asked to undergo blood hemoglobin and oral glucose tolerance tests. A total of 12ml venous fasting blood samples were obtained from each participant. Of this, 3mL was drawn into an ethylene diamine tetraacetic acid tube for complete blood count, 3ml was drawn to a sodium fluoride tube for blood glucose analysis, and 6 ml of the blood sample was drawn to a plain tube for serum preparation for future analysis. After 2 hours of consumption of 75 gm of anhydrous glucose water, the second blood sample was drawn.

GDM(Gestational diabetes mellitus): World Health Organization cut-off measurement was used to diagnose gestational diabetes mellitus. Fasting blood glucose levels (≥92 mg/dl) and 2-hour samples (≥153mg/dl) were cut-off measurements.²⁸

Outcome

Blood hemoglobin estimation was done for all study participants after the completion of 24 weeks of gestation. World Health Organization standard (Hb<11gm/dl) was used to determine the anemia status in pregnancy. Hemoglobin concentration in the 10-10.9 gm/dl range was considered mild, 7-9.9 gm/dl moderate, and <7 gm/dl severe anemia.²⁹ The participants were followed up at birth and one year subsequently. The infants were assessed for morbidity, feeding practices, child developmental milestones, and detailed anthropometric measurements.

Statistical Analysis

Descriptive analysis was performed to summarize demographic characteristics and obstetric history. The frequency and percentage of participants who were anemic were calculated. Anemia was categorized as normal, mild, and moderate, and the predictors for maternal anemia were investigated through a multivariate regression model. The analysis was performed using IBM statistical software SPSS version 23.

Results

A total of 2447 study participants with a mean age of 24.28 ± 4.07 years were included in the study. The majority were below 25 years of age (65%), had attended high school education (45%), and were Hindus (51%). Nearly 56% of the study participants belonged to a lower socio-economic class, and 30% reported a spouse’s habit of smoking cigarettes.

Concerning the obstetric history, 45% were primigravida, and 19.7% had a history of abortion. Of the total subjects, nearly 9% experienced depressive symptoms during pregnancy, and the majority (73%) had good social support. More than 46% of pregnant women were obese, and 13.9% were diagnosed with gestational diabetes (Table 1).

Several socio-demographic, obstetric, and dietary variables were significantly associated with anemia. These included lower socio-economic status, presence of single earning members, and husband’s education. Among the obstetric factors, primipara was negatively associated with anemia. Women with gestational diabetes had 26.7% higher odds of anemia, whereas hypertensive women had 56.3% higher odds compared to normal women (Table 2).

A multivariate analysis adjusted by possible potential confounders such as the age of the respondent, socioeconomic status, and education showed that increasing parity [AOR:1.247, 95% CI: 1.09,1.42] had 24.7% higher odds of developing anemia when compared to nulliparous women. Not consuming IFA tablets [AOR: 1.247, 95% CI: 1.05, 1.48] conferred 24.7% higher odds of anemia when compared to those who consumed IFA tablets. Underweight in pregnant women was associated with 30% higher odds of anemia (Table 4).

Discussion

Our study found a higher prevalence of maternal anemia during pregnancy in urban Bengaluru. The main obstetric factors significantly associated with maternal anemia were parity and nutrition-specific factors such as being underweight and not consuming iron supplements.

Our data demonstrated a higher prevalence of anemia in pregnant women than the previously reported prevalence in a similar geographical study by Vindhya J et al. (33.9%) (30) and Samuel T et al. (30.3%).³¹ Notably, our observed prevalence was comparatively lower than reported rates in various districts of Karnataka, such as 50.1% in Udupi, 62-64% in Kolar, 64.5% in Tumkur 35, and a range of 72.5% to 86.37% in Belagavi.^32-34,36,37 The geographical disparity could be attributed to the difference in prevalence. The prevalence of anemia in India remains one of the public health issues despite the rigorous efforts of the government to reduce anemia in terms of free distribution of meals and IFA supplements and free advice and counseling on nutritional requirements during pregnancy.

Failure to consume IFA tablets, the nutrition status of pregnant women, especially being underweight, and an increase in parity were significant predictors of anemia. These findings were supported by a descriptive cross-sectional study in Belagavi that showed that multiparous women were significantly associated with anemia and result by Mehrotra M et al. ^37,38 The results of the most recent demographic survey data supported our evidence of increased odds of anemia among underweight women during pregnancy.³⁹ A cohort study in China showed a positive association between lower body weight during pregnancy and maternal anemia. The results also provided evidence that irregular IFA supplementation during pregnancy is associated with seven times higher odds [AOR:7.05 (1.06–46.81)] of anemia during the third trimester of pregnancy. Another Ethiopian study also revealed that the irregular consumption of IFA had higher odds of anemia during pregnancy.^40-42 However, our findings contradict the existing studies conducted in India, where IFA supplements did not show any significant association with anemia.^39,43 Like other studies, we did not find an association between the level of education of women and their husbands, tobacco smoking, previous history of abortion and anemia.^44-49

Our study has several strengths. The study included a larger number of participants compared to other studies. Secondly, we estimated the hemoglobin concentration of each participating woman and did not consider the hospital record values. The National Accreditation Boards for Testing and Calibration Laboratories (NABL) accredited laboratories conducted hemoglobin assessment. The study did not collect pre-pregnancy BMI status and considered skinfold thickness as a reliable measure of nutrition status.

Conclusion

Although IFA supplementation and one complete meal nutrition program are available for pregnant women to address the specific issues, but anemia remains a significant public health issue. We observed that modifiable dietary factors such as undernutrition and failure to consume IFA supplements are significantly associated with anemia during pregnancy. The government should take proactive health promotion initiatives, such as effective campaigns and supervise the intake of iron tablets to resolve this problem. Integrated dietary interventions such as food fortification, nutrition education, and IFA supplementation targeting from childhood to adolescence and reproductive age rather than targeting pregnant women may help to reduce the burden of anemia. To reduce anemia during pregnancy, improving women's access to information on the risks of underweight and higher parity is necessary. The implications of not consuming regular IFA supplements during pregnancy are also important.

Conflict of interest

None