Study design, period and setting
Institution based cross sectional study was conducted to assess prevalence and associated factors of undernutrition among pregnant women visiting ANC follow up clinics of health facilities. It was conducted from July to January 2019 in Silte Zone .It is one of fourteen Zones of the southern region of Ethiopia and found 172 km away from Addis Ababa (the capital city of Ethiopia). The administrative center of the zone is Werabe town. This zone consists of an administration town, and 12 rural weredas. Based on last Census conducted by the central statistical agency of Ethiopia, in 2018 the Zone has estimated population of 1,017,557 of whom 156915 are under five children .About 13% of the total population is urban inhabitants. In addition there are 04 Hospitals and 33Health centers
Sample size determination and sampling technique
The sample size (n) required for the study was calculated using a single population proportion formula. Considering the absence similar study conducted at similar context as per our search effort, we took p value of 50%, 5% marginal error, and 95% confidence interval were used to obtain the maximum sample size. With the addition of 10% contingency, initial sample size was increased to 422. In the study area, antenatal care service is provided in all health care facilities. In order to increase the generalizability of the results, health facilities were stratified based on the type of health facility, 1 hospital (Tora Primary Hospital) from the four hospitals and 10 health centers from the 33 health centers were selected randomly. Calculated sample size was allocated proportionately to selected health facilities. According to the health facilities report, on average, 20–35 pregnant women visit the ANC daily and 2066 pregnant women have been enrolled in ANC of selected health facilities. Since the sample size was determined as 422. Fifty two from Tora Primary hospital and 380 from 10 health centers were selected using systematic random sampling technique at interval of k = 5. Of the first five pregnant women, 3rd woman was randomly selected by using lottery method. Accordingly, every 5th pregnant women were selected to participate in the study until the required sample size of 422 pregnant women was obtained.
Measurements and data collection tools
Interviewer-administered questionnaire was used to collect the data which was adopted from articles published in peer reviewed journals. Knowledge questions were adopted from FAO knowledge, attitude and practice survey guideline . Measurement of middle upper arm circumference (MUAC) was used to determine Nutritional status of the pregnant women. MUAC of the left arm was measured triplicate using a non-stretchable standard MUAC tape to the nearest 0.1 cm with no clothing on the arm. The mean of triplicate measurement was taken. Pregnant women having MUAC< 23 cm were considered undernourished and ≥ 23 cm well-nourished (23, 29, 30)
Data Quality Control
Trained data collectors collected the data. The instrument was pretested in 5% of the sample size. It was conducted on individuals with similar characteristics of the study population who were not a part of the actual study. Based on the pretest results, the instrument was modified and changed into local contexts. Trained supervisors supervise the data collection and check the completeness of the questionnaire on the daily base. In addition, principal investigators carefully cleaned and entered collected data into a computer. During the entry of data, double entry verification using Epidata 3.1 was applied.
Data processing and analysis:
Data was entered into a computer using Epi data 3.1, and edited, cleaned and analyzed using SPSS version 20. Bivariable and multivariable logistic regression was used to determine the degree of association between independent and dependent variables. Variables with p value of < 0.25 in Bivariable logistic regression analysis were candidates for multivariable logistic regression analysis. In multivariable logistic regression analysis, those variables with a p value ≤ 0.05 with adjusted odds ratio interval exclude one was considered as statistically significant.