The burden of Anemia in pregnancy between 2005 and 2015
The burden of anemia remains high among women of reproductive age despite a slight decline from 48.4% in 2004 to 44.8% ten years later in 2015. The burden is even higher among pregnant women compared to non-pregnant women in both survey years (p<0.001). The burden has remained 57.1% among pregnant women in 2015 from 58.2% in 2005 (P=0.680). This means, there has not be any significant decline of anemia in pregnancy for over 10 years between the surveys (Table 1). Among pregnant women with anemia, a sheer majority had a moderate form in both surveys. There has been a significant decline of severe form of anemia from 2.7% in 2005 to 1.2% in 2015 (p=0.017).
Despite the stagnation of the overall burden of anemia in pregnancy, analysis by region showed changes between regions (Figure 1). A total of 15 regions observed a decline of anemia among pregnant women in Tanzania. The magnitude of change was observed more in Mara (23.2%), Njombe (16.5%), Singida (14.7%), Dodoma (12.4%), and Rukwa (11.9%). On the other hand, we noted an increase in the burden of anemia 16 regions and at a various level of change. Regions with a higher increase of anemia included Kigoma (24.1%), Ruvuma (19.7%), Kusini Pemba (12.5%), Kusini Unguja (12.3%), and Lindi (11.6%). [see Additional file 1.docx]
Characteristics of anemia among pregnant women in Tanzania
Table 3 shows the descriptive characteristics of pregnant women in relation to anemia status between the two survey years. The burden of anemia among pregnant women was higher in two age extremes in both surveys. Younger women especially below 20 and older ones above 40 years old had higher burdens compared to other age categories. Although not statistically significant, education played a proactive role for anemia. Women with health insurance were more likely having lower burden of anemia. In both surveys, the larger the number of people in the household was related to a higher risk of anemia among pregnant women. Similar was for wealth index—lower risk of anemia among pregnant women living in wealthier households and households with food insecurity.
With regards to reproductive and child characteristics, descriptive analyses suggest that although not significant, the burden of anemia was higher among women who gave birth to their first child at the age of 19 and below. Those with higher number of ANC attendances were less likely to have anemia. Anemia burden was low among those given iron tablets. In both surveys, the burden of anemia was higher among those who gave their previous birth at home compared to health facilities, those who were dewormed, and given antimalaria.
Net change of anemia among pregnant women in Tanzania
After adjusting for individual, households, reproductive, and child characteristics that seems to have some association with anemia in the general characteristics above, this study found no significant change or decline of anemia among pregnant women in Tanzania between 2005 and 2015, AOR 0.964, 95% CI (0.774- 1.202), p=0.747 (Table 3). In this particular regression analyses, we adjusted for age, highest education level, current marital status, type of residence, number of household members, wealth index, and number of children ever born. In this particular analysis we also adjusted for survey weights.
The current burden of anemia among pregnant women and its determinants in Tanzania
Over the period of ten survey years (from 2005 to 2015), there has been an improvement in 15 regions while 16 regions in Tanzania mainland and Zanzibar deteriorated [see Additional file 1.docx]. In the most recent survey (2015-2016), anemia among pregnant women was highest in Kaskazini Pemba (81.4%) followed by Pwani region (79.6%), Kigoma (77.1%), Shinyanga (74.5%). Anemia was the lowest in Njombe region (18%). Figure 2 shows the burden of anemia as of 2015-2016 national representative survey.
After adjusting for covariates and confounders, there was no difference of the burden of anemia among pregnant women between rural and urban areas in Tanzania (Table 4). Compared pregnant women living in households with up to 3 members, those in bigger size households were more likely to have anemia. For example, compared with households with up to three household members, pregnant women in households with up to six members were 1.3 times more likely to suffer from anemia (p=0.010); in households with up to 9 people were more than 1.5 times more likely to suffer from anemia (p<0.001) and those with more than ten members were more than twice more likely to suffer from anemia (p<0.001). Women in higher than the first and subsequent wealth quintile were less likely to suffer from anemia, though such association did not reach a statistically significant level.
Anemia was rampart among young pregnant women aged 15-19 years. Pregnant women aged between 20-34 years of age were less likely to succumb anemia compared to young pregnant women aged 15-19 years of age. For example, those between 20-24 were 24% less likely to suffer from anemia (p=0.034), those between 25-29 were 33% less likely to have anemia (p=0.010), and those between 30-34 were 35% less likely to suffer from anemia (p=0.010), compared to late teenage pregnant mothers. Although older women were less likely to succumb anemia compared to teenage pregnant mothers, such association did not reach a statistically significant level.
Any level of education among pregnant women in Tanzania was beneficial and protective against anemia in pregnancy compared to no education at all. For example, compared to pregnant women with no education, those with primary education were 31% less likely to succumb from anemia (p<0.001) and those with secondary school and above education were 26% less likely to succumb from anemia (p=0.007). Pregnant with previous birth experience were more likely not to have anemia compared to those whose pregnancy was the first. For example, those with three previous pregnancy were 22% less likely to suffer from anemia compared to those with the current pregnancy (p=0.044).
Food insecurity has a role to play in anemia during pregnancy. Although the association did not reach a statistically significant level, compared to women in food insecure households, those from households with adequate food were 11% less likely to suffer from anemia (p=0.052). Likewise, those who were covered by some form of health insurance were 30% less likely to succumb from anemia (p=0.003). Women who were given antimalaria during pregnancy were 12% less likely to suffer from anemia during pregnancy (p=0.040). Place of delivery during the previous pregnancy seems to have a role in predicting the current pregnancy’s anemia. Those who delivered in public health facilities and private health facilities were 26% (p=0.013) and 36% (p<0.001) less likely to succumb from anemia in the current pregnancy compared to those who delivered at home. Women who attended ANC clinics in required frequency were 11% less likely to suffer from anemia in pregnancy (p=0.050).