Prevalence of iodine deficiency and associated factors among pregnant women in Ada district, Oromia region, Ethiopia: a cross- sectional study

Abstract

Background: Maternal iodine deficiency (ID) during pregnancy has been recognized as a major cause of abortion, stillbirth, congenital abnormalities, perinatal mortality and irreversible mental retardation. In Ethiopia limited information is available regarding the epidemiology of maternal ID. The purpose of the present study was to assess the prevalence of iodine deficiency and associated factors among pregnant women in Ada district, Oromia region, Ethiopia.

Method: A community based, cross-sectional study was conducted in rural areas of Ada district, October to November, 2014. Data were collected from 356 pregnant women selected by multistage cluster sampling technique. Presence of goiter was examined by palpation and urinary iodine concentration was measured using inductively-coupled-plasma mass spectrometry. Salt iodine concentration was determined using a digital electronic iodine checker. Statistical analysis was done primarily using binary logistic regression. The outputs of the analysis are presented using adjusted odds ratio (AOR) with the respective 95% confidence intervals (CI).

Results: The median urinary iodine concentration (UIC) was 85.7 (interquartile range (IQR): 45.7-136) μg/L. Based on UIC, 77.6% (95% CI: 73.0-82.0%) of the study subjects had insufficient iodine intake (UIC < 150 μg/L). The goiter rate was 20.2% (95% CI: 16.0-24.0%). The median iodine concentration of the household salt samples was 12.2 (IQR: 6.9-23.8) ppm. Of the households, only 39.3% (95% CI: 34.0-44.0%) consumed adequately iodized salt (≥15 ppm). Prevalence of goiter was significantly higher among pregnant women aged 30-44 years (AOR = 2.32 (95% CI: 1.05-5.14)) than among younger women and among illiterate women (AOR = 2.71 (95% CI: 1.54-4.79)). Compared to nulliparous, women with parity of 1, 2 and 3 or more had 2.28 (95% CI: 1.01-5.16), 2.81 (95% CI: 1.17-6.74) and 4.41 (95% CI: 1.58-12.26) times higher risk of goiter.

Conclusion: Iodine deficiency was a public health problem in the study area. This indicates the need for further strengthening of the existing salt iodization program in order to avail homogenously and adequately iodized salt. Also it is necessary to find ways to provide iodine supplements as needed until universal salt iodization (USI) is fully established.

Keywords: Goiter; Iodine deficiency; Iodized salt; Pregnant women; Urinary iodine.