Strengths and limitations of this study
This study is one of the few population studies witch are investigate postpartum anemia. Indeed, most of the data in the literature on the subject concern samples in a hospital environment. As a result, we filled a major gap that was the lack of postpartum anemia prevalence data in the similar countries.
However, important limitations are to be taken into account when analyzing the DHS data: first, the data are from 2010, so the current situation may have changed. Next, we did not have any variables that indicated the clinical status of women during pregnancy, particularly in terms of general illnesses or health events that could explain the subsequent occurrence of anemia in the postpartum (placenta previa, bleeding during pregnancy, anemia during pregnancy, etc.). In addition, the DHS database does not collect a certain number of very important variables in the occurrence of anemia in the postpartum, including the quantification of blood loss during childbirth, the actions performed during the birth delivery as an administration of oxytocic, the realization of an episiotomy, etc. Finally, the biological characteristics of anemia (mean cell volume, mean corpuscular concentration of hemoglobin) were not collected. This characterization could have focused more on the factors most likely to justify anemia in the postpartum in women. These limitations may have contributed to reducing the quality of the statistical analysis of associated factors. But by opting for a multilevel analysis, we have also improved the quality of the results by controlling a possible correlation that might exist between women in the same cluster. Moreover, the exploratory results showed the relevance of such an analysis because the intraclass correlation coefficient (ICC) was 0.24 taking into account 3 levels: woman, household and clusters.
Prevalence of postpartum anemia
Hemoglobin levels were less than 12 g/dl in 51.9% of women. Moderate to severe anemia (Hb levels below 10 g/dl) were found in 15.5% of cases. Heterogeneity of thresholds for defining postpartum anemia has been noted in the literature, making comparisons difficult. Indeed, while some studies have considered mild or severe anemia, others have just chosen to address the issue in women whose anemia was moderate or severe (case of our study). Also, most of these studies were conducted in hospitals. The prevalence of moderate to severe anemia found in our series testifies to the problem of anemia in our country. This is all the more so since this high prevalence could contribute to maintaining already significant maternal mortality in our context. Lakew et al reported an anemia prevalence of 22.1% in 2015, considering a threshold of 12g/dl in a population of 7332 lactating women in Ethiopia. [9]. Bergman et al noted a higher prevalence (22%) of moderate or severe anemia (Hb level below 10 g/dl) in a large retrospective study of 43,807 women who gave birth between 1993 and 2008 [13]. However, this latest study only involved women in the immediate postpartum (48 hours of postpartum). Our study concerned the expanded postpartum to twelve months after delivery. This longer period would help reduce this prevalence of moderate or severe anemia in our study. Indeed, physiologically, blood losses are compensated in a few weeks or even months, following their occurrence if all physiological mechanisms are not altered and also if these losses are not severe. In 2009, Somdatta et al in a cross-sectional study in a village in northern India reported a 70% prevalence of postpartum anemia by setting a threshold for hemoglobin levels below 11g/dl [14]. In 2014, Rakesh et al in India found a prevalence of 47.3% by the sixth week of postpartum with a threshold value of 12g/dl [15]. Other proportions, still high, were found as 60.3% in 2014, by Zhao et al among lactating women in Myanmar [4] and 62% by Trinh et al in Vietnam in 2007 [16] and finally 29% by Garrido et al in Spain among women in postpartum [1 7].
A constant emerges from the various studies: this is the high proportion of anemic women in the postpartum regardless of the period thresholds set (from a few weeks to a few months), regardless also of the threshold value used for the hemoglobin level. However, Bhagwan et al reported a very low prevalence of moderate anemia in India in 2016 (0.6%) without any cases of severe anemia [18].
Factors associated with moderate to severe postpartum anemia
In multivariate analysis, the region, postpartum amenorrhea status and marital status were the main factors associated with postpartum anemia with lightly degree of significance. No association was noted with a number of factors found in the literature. These included breastfeeding [8.9], professional activity [19], wealth quintile [4], age [15, 19], ethnicity [16], educational attainment [4, 16, 18] and race [8, 17, 18, 20, 21]. The same was true for variables such as multiple pregnancies [13], caesarean delivery [17] and postnatal consultation within two months of delivery [22], obesity [8], and parity [22]. The administrative region was associated with moderate or severe postpartum anemia, with two regions acting in the opposite way. Indeed, while belonging to the Sahel region was a risk factor for postpartum anemia, belonging to the Hauts-Bassins region was a protective factor (reducing the risk of postpartum anemia) when comparing these two regions to Central Region. Geographical factors combined with other factors such as cultural practices coupled with religious practices and eating habits may explain these differences. However, in our series, some key variables were not included in the analysis model because of their sensitivity: religion and ethnicity.