Third trimester maternal anemia is associated with fetal cardiovascular compromise in Southwestern Uganda

Maternal anemia is still a global public health burden during pregnancy. It impairs fetal-placental perfusion leading to fetal hypoxia, that disrupts vital physiological and biochemical pathways. This affects fetal growth and developmental programming, resultant into advance. perinatal outcomes and susceptibility to various non-communicable diseases later in life. This study set out to established how clinical Doppler and other physiological cardio, cerebral and peripheral vascular parameters vary at various grades of maternal anemia. A cross-sectional study was conducted among women aged 20–35 years, with singleton third trimester pregnancies attending Mbarara Regional Referral Hospital between March 2023 and August 2023. These were grouped into non-anemic with Hemoglobin concentration ≥ 11 g/dL, while mild anemia (Hb:10–10.9 g/dL), moderate anemia (7–9.9 g/dL), and severe anemia Hb < 7 g/dL. Resistance to flow and flow distribution were assessed by Doppler-derived indices and ratios of the fetal middle cerebral artery (MCA) and umbilical artery (UA). Physiological parameters like volumetric flow were calculated from measurements. We compared means using ANOVA and evaluated the relationships between flow parameters and the severity of anemia using Spearman’s correlation coefficient. We enrolled 288 participants with a mean age of 27 ± 4.3 years. The UA resistance indices among the non-anemic were significantly lower than among the anemic and significantly escalated from among the mild to the severely anemic, for instance, UA-PI increased from (0.88 ± 0.18) among the mild, moderate (0.92 ± 0.24) to (1.09 ± 0.34) severe anemia, (p < 0.001), while the mean flow velocity decreased as anemia severity increased (F [3,284] = 3.44, p = 0.017). The mean cerebral flow velocity demonstrated an increasing trend with the severity of anemia (p = 0.042). Similarly a lower mean Cerebral placental Ratio was noted in the anemic group (1.87 ± 0.49) compared to the non-anemic group (2.15 ± 0.53), (p < 0.001), while as maternal Hb concertation reduced, the CPR significantly decreased, (r = 0.31, F[3,284] = 12.64, p < 0.001). As the maternal hemoglobin concentration reduced, the fetal heart rate increased (r= -0.06, p = 0.308). Anemic women exhibited higher UA flow resistance, lower Cerebral placental ratio, suggestive of altered flow patterns with increasing severity of maternal anemia. These findings suggest that maternal anemia influences umbilical artery hemodynamics, potentially responsible for compromised fetal well-being. Understanding these associations could contribute to enhanced antenatal care strategies, emphasizing the importance of monitoring maternal anemia and its potential implications on fetal cardiovascular health.