This study aimed to assess the prevalence of anemia, association between umbilical cord anemia and maternal anemia, and risk factors for newborn anemia at a regional referral hospital in southwestern Uganda.
The prevalence of newborn anemia in this study was 17%, lower than the prevalence reported in previous cross-sectional studies. For example, prior studies in Ethiopia reported a prevalence of newborn anemia ranging from 23% to 25% (Tiruneh, Shiferaw and Enawgaw, 2020; Alamneh et al., 2022). However, these studies were conducted in a largely rural setting compared to our semi-urban study population. Prior studies in RLS have noted that anemia is more prevalent in rural than urban and semi-urban populations (Tesfaye, Tessema and Jarso, 2020), which may partially explain these differing findings. In contrast, the prevalence of anemia in our populations was higher than what has been reported in the USA, Nepal and Ethiopia which reported prevalence rates of 14%, 6% and 9%, respectively (Terefe et al., 2015; Lee et al., 2016; Timilsina et al., 2018). These differences in anemia prevalence could be attributed to differences in socioeconomic conditions and clinical characteristics of the study participants. Additionally, the differences could also be because in some previous studies, specifically (Terefe et al., 2015), women with only iron deficiency anemia (IDA) were included, whereas our study included anemia of any cause.
We found a significant positive correlation between maternal and umbilical cord hemoglobin concentration. For every 1-point increase in maternal hemoglobin, there was a corresponding 0.14-point increase in umbilical cord hemoglobin. The finding of a positive correlation between maternal and umbilical cord haemoglobin in this study is similar to other studies in Nigeria, Kenya, Israel, India and Iran (Kuile et al., 1999; Dapper and Didia, 2007; Alizadeh et al., 2014). Since the fetus obtains iron from maternal transferrin, when maternal iron stores are depleted, the fetus cannot accumulate as much iron resulting in a decrease in fetal iron stores and reduced fetal hemoglobin levels (Bergmann et al., 2010; Kosto et al., 2015; Shukla, Srivastava and Verma, 2019; Alegbeleye, Abam and Orazulike, 2020; Rathoria and Rathoria, 2021). The physiological changes and metabolic demands of pregnancy result in an increased requirement for iron in pregnancy (Kohli, Rajput and Venkatesan, 2021) predisposing to maternal anemia. Maternal anemia leads to adaptations in placental and fetal physiology resulting in pregnancy and birth complications such as low birth weight, neurodevelopmental disorders and premature delivery (Dane et al., 2013; Wiegersma et al., 2019; Rahmati et al., 2020).
We also found a statistically significant association between parity and umbilical cord hemoglobin levels, with a 0.25-point decrease in umbilical cord hemoglobin for every one-unit increase in parity (P<0.01). Higher parity increases the risk of developing iron deficiency anemia in pregnancy, and the incidence of anemia has been shown to increase with the number of pregnancies (Kumari and Badrinath, 2002; Çelik Kavak and Kavak, 2017; Shah, Warsi and Laghari, 2020; Vionalita and Permata, 2020). This association could be attributed to depletion of maternal iron stores with each subsequent pregnancy or to inadequate spacing between pregnancies that often comes with high parity and is common among Ugandan mothers (McGuire and Stephenson, 2015; Aleni, Mbalinda and Muhindo, 2020; Tiwari and Mishra, 2020; Belaid et al., 2021).
In addition, we found that cesarean delivery was significantly associated with a 0.46-point decrease in umbilical cord hemoglobin level. Cesarean delivery has previously been described to increase the risk of postpartum anemia by two-fold (Bergmann et al., 2010), due to the increased risk of uterine atony and severed vessels when the abdominal wall is opened (Joseph et al., 2007; Kramer et al., 2013). Lastly, we found that lower wealth, measured using the asset index, was associated with lower umbilical cord hemoglobin levels. These findings are similar to those in other settings (Lokare et al., 2012; Hooja et al., 2020), although a study in Indonesia found no direct relationship between the socioeconomic status and anemia (Faculty of Medicine, Universitas Methodist Indonesia et al., 2019). Women with lower socioeconomic status may have limited access to nutritious food, which can lead to poor maternal nutritional status and subsequent fetal anemia (Pell et al., 2013). We found a significant positive correlation between maternal and newborn hemoglobin levels. Parity, cesarean delivery, and lower asset index quartile were significantly associated with newborn anemia. Such information is required to institute early interventions to reduce anemia-associated complications. This underscores the importance of preventing maternal anemia and maintaining adequate iron stores in pregnancy.