Anemia remains a significant health problem globally, accounting for more than 60,000 maternal deaths and 3.4% of global disability-adjusted life years in women aged 15–49 years. According to the World Health Organization (WHO), globally, 528.7 million (29.4%) women of reproductive age are anemic with a hemoglobin (Hb) concentration of < 11 g/dL. Of these women, 20.2 million are defined as severely anemic with a Hb concentration of < 7 g/dL. Rates of anemia are highest in low-resource countries, especially in central and west Africa where 48% of reproductive-age women and 56% of all pregnant women are reported to be anemic and in South Asia, where 47% of all reproductive-age women and 52% of pregnant women are reported to be anemic.
Multiple adverse maternal and neonatal outcomes have been attributed to anemia. These outcomes vary according to the severity of anemia. Reported maternal and perinatal outcomes among severely anemic women include premature rupture of membranes, preterm births (PTB), hypertensive diseases of pregnancy, puerperal pyrexia, fetal distress, small for gestational age, stillbirths, neonatal and maternal deaths. Findings from systematic reviews and meta-analyses have also suggested that in low-income countries, 25% of low-birth weight (LBW), 44% of PTB, and 21% of perinatal mortality are attributable to anemia. One review observed a relatively higher anemia-attributable proportion of LBW in Pakistan and Bangladesh compared to Ghana and India. Similarly, the highest anemia-attributable proportion of PTB was observed in Pakistan (54%) followed by India (27%) and Iran (18%). Further, studies have also revealed that women with low Hb concentrations during pregnancy are at higher risk of antepartum and postpartum hemorrhage, obstructed labor, and cesarean-section delivery when compared to the women with normal hemoglobin concentrations.
At the other end of the spectrum, several older studies have shown that elevated Hb concentrations during pregnancy are also associated with increased risk of adverse birth outcomes, including PTB, LBW, fetal death and intrauterine growth retardation. However, the findings have not been consistent. Moreover, this potential U-shaped relationship, with higher risks of adverse birth outcomes at both extremes of Hb concentrations have been assessed primarily in more developed countries such as the U.S., Sweden, and Iran. Thus, very few studies have described the relationship between high Hb concentrations and birth outcomes in low-and middle-income countries (LMIC) and particularly in women from South Asia. Moreover, the relationship between higher concentrations of Hb with adverse outcomes, such as antepartum and postpartum hemorrhage, obstructed labor, and cesarean delivery is not explored in the literature.
The objective of this study was to assess the associations across the range of maternal Hb concentrations and adverse birth outcomes in South Asian pregnant women as well as evaluating factors related to Hb concentrations by country. Differences between the Pakistani and Indian sites in the relationship of Hb concentration and pregnancy outcomes were explored. An understanding of these outcomes and the association of Hb concentrations with adverse pregnancy outcomes is essential to inform policies to improve maternal and fetal/neonatal outcomes.
By: Ali SA, Tikmani SS, Saleem S, Patel AB, Hibberd PL, Goudar SS et al.