Zinc deficiency and associated factors among pregnant women’s attending antenatal clinics in public health facilities of Konso Zone, Southern Ethiopia

Background Zinc is an essential mineral known to be important for the normal physiological functions of the immune system. It is one of the basic nutrients required during pregnancy for the normal development and growth of the fetus. However, Zinc deficiency during pregnancy causes irreversible effects on the newborn such as growth impairment, spontaneous abortion, congenital malformations and poor birth outcomes. Even though, the effect of Zinc deficiency is devastating during pregnancy, there is scarcity of evidence on Zinc deficiency and related factors among pregnant women in the current study area. Objective To assess Zinc deficiency and associated factors among pregnant women attending antenatal clinics in public health facilities of Konso Zone, Southern Ethiopia. Methods Institution based cross-sectional study was conducted among randomly selected 424 pregnant mothers. Data were collected using pre tested questionnaire (for interview part), and 5 blood sample was drawn for serum zinc level determination. Data were entered to Epi-Data version 3.1 software and exported to SPSS version 25 for analysis. Binary logistic regression analysis was computed and independent variables with a p-value ≤ 0.25 were included in multivariable analysis. Serum zinc level was determined using atomic absorption spectroscopy by applying clean and standard procedures in the laboratory. Finally adjusted odds ratio with 95% confidence level, P-value < 0.05 was used to identify significant factors for Zinc deficiency. Result The prevalence of Zinc deficiency was found to be 128 (30.26%) with the mean serum zinc level of 0.56±0.12 g/dl. Age, 25–34 years [AOR 2.14 (1.19,3.82)], and 35–49 years [AOR 2.59 (1.15, 5.85)], type of occupation, farming [AOR 6.17 (1.36, 28.06)], lack of antenatal follow up during pregnancy [AOR 3.57 (1.05,12.14)], lack of freedom to purchase food items from market [AOR 3.61 (1.27, 10.27)], and inadequate knowledge on nutrition [AOR 3.10 (1.58, 6.08)] were factors associated with Zinc deficiency. Conclusion Zinc deficiency is a public health problem among pregnant mothers in the current study area. Improving maternal nutritional knowledge, motivating to have frequent antenatal follow up, and empowering to have financial freedom to purchase food items from market were the modifiable factors to reduce Zinc deficiency. Nutritional intervention that focused on improving nutritional knowledge and insuring access to Zinc sources food items should be delivered for pregnant mothers. This study was carried out in Konso Zone Public health facilities, Southern Ethiopia. The live hood of the Konso community is mixed farming; crop cultivation complimented by small live stock holdings. The health care was delivered in the Konso zone in government owned health centers and district hospital [15]. The data was collected from May 1 to June, 2020. Institution based cross-sectional study was conducted among systematically selected pregnant mothers who had antenatal follow up in the public health facilities. Pregnant mothers who had known medical illness and mentally incompetent for interviews were excluded from the study. The sample size for this study was calculated using single population proportion formula by taking the prevalence of zinc deficiency (P) = 57.4%, study done in North West Ethiopia [16], margin of error (d) = 5%, 95% confidence level and determined to be 376. By taking 15% none response rate, the final sample size became 432. From the existing public health facilities in Konso Zone three health centers were selected randomly by lottery method and the hospital was selected purposely. The study participants were allocated proportionally to each of the selected health facilities based on the participants’ flow for antenatal care. Base line data was collected from 3 heath centers and one district hospital for one month to get the actual number of pregnant mothers. Based on the collected data from the antenatal loge book, there were 242, pregnant mothers in health center one, 176 in health center two, 198 in health center three, and 374 pregnant women from the district hospital. Then each study participant was allocated proportional based on the population size. By this assumption, 105 pregnant mothers from health center one, 76 from health center two, 86 from health center three and 165 pregnant mothers were selected from the district Hospital. Finally systematic random sampling method was implemented to select the study participants for interviews and blood sample collection. Data was collected using pre tested structured questionnaire for survey part and blood sample was taken for serum zinc level determination. The questionnaires were prepared in English and translated in to Amharic (the national language for Ethiopia) for interviewing the participants. Women dietary diversity data was collected by using 24 hr. dietary recall methods. A well trained clinical BSc nurses and laboratory professionals were recruited to collect data from the respondents. After getting informed consent from the respondents, the actual data collection process was conducted. After interviewing, blood sample was collected from the pregnant mothers. Venous blood was collected using plain tube and stainless steel needles. The collected blood was allowed to clot for 20 minutes and centrifuged at 3000 revolution per minute. Visibly hemolysis blood sample was discarded. Serum was extracted and transferred immediately into screw-tub vials. Each collected serum sample was kept at -20°C until transportation. Then the stored serum was transported to Arba Minch University, Abaya campus food and chemistry laboratory. The quality of data was assured before, during and after data collection. During data collection, supervisors and principal investigators were closely followed the day-to-day data collection process and ensure completeness and consistency of questionnaire administered each day. Blood sample quality was maintained by implementing clean and standardized procedure during laboratory analysis. Serum zinc concentration was determined using flame atomic absorption spectrometry. Atomic absorption sspectroscopy was equipped with deuterium ark background correctors, hallow cathode lamps for each respective element, and air-acetylene flame. Atomic absorption spectroscopic standard solutions containing 1000 mg/L was used for preparing intermediate standard solutions (10 mg/L) by diluting in 100 ml volumetric flask using deionized water. Aseries of working standard solutions was prepared from the intermediate standard solution by 50 ml volumetric flask with 0.2, 0.4, 0.8, 1.6 mg/L concentration [17, 18]. Four points of calibration curve was established by running the prepared standard solutions in flame atomic absorption spectrometer (FAAS) Immediately after calibration, the prepared sample solution was aspirated into the FAAS instrument and direct readings of the absorbance for Zn was performed. The collected data was checked visually by the investigators, then entered to Epi-Data version 3.1 software and exported into SPSS version 25 for analysis. Descriptive statistical analysis such as simple frequencies and measures of variability were used to describe the characteristics of the participants. Then the results were presented using frequencies, tables, and figures. Wealth index was computed as a composite indicator of living standard by using Principal Component Analysis (PCA). Orthogonal rotation method using varimax was used to maximize loadings of variables on the extracted factors. Kaiser’s stopping rule which considers factors with Eigen values greater than 1.0 was retained. Using the factor scores from the first principal component as weights, classified households into quintiles and calculated the mean socio-economic score for each study participant [19, 20]. Binary logistic regression analysis, COR with 95% CI, was used to see the association between each independent variable and the outcome variable. Independent variables with a p-value of ≤0.25, were included in the multivariable logistic regression analysis model. Level of statistical significance was declared at p-value < 0.05. Zinc deficiency—Serum zinc concentration deficiency was defined as a serum zinc level of less than 56 μg/dl during the first trimester or less than 50 μg/dl during the second or third trimester [21, 22]. Dietary Diversity Score–it was measured by using Minimum Dietary Diversity–Women defined as a dichotomous indicator as low who consumed less than (≤5) food items and higher if it is greater than (≥5) out of ten defined food groups during 24 hours [23]. Wealth index–it is difficult to measure the income of pregnant mothers in study setting because the occupational status of these mothers were farmer, house wife and trader, so it is difficult to measure by using monthly income. Therefore the wealth index was measured by using principal component analysis by taking the higher score. Then each score was categorized in to five cut of points and further categorized as poor (the 1st and 2nd cut of points), medium (cut of points 3), and rich (for 4th and 5th cut of points [19, 20]. Having Nutrition knowledge: it was measured by using women nutritional knowledge assessment tool which categorized as having good if she correctly answered greater than or equal to 70% of the total knowledge assessing questions [24]. Financial freedom- of pregnant mother was measured by using tools that are used in similar setting to determine pregnant mother’s financial access to purchase quality food items from the local market without their husband influence which was categorized as having freedom and not having freedom [25]. Ethical clearance was obtained from Institutional review board (IRB) of Arba Minch University, college of Medicine and Health Sciences. The formal permission letter was obtained from the respective health facilities administrator office. Informed consent was obtained from the study participants. Needle safety procedures were in line with world health organization standard. Pregnant mothers who were zinc deficient were referred for supplemented with zinc in collaboration with respective health institutions and adequate health education was given.