I. Introduction
Hemoglobin is formed by the combination of heme and globin peptide chains. Its main function is to transport oxygen and carbon dioxide to maintain the acid-base balance in the blood. During pregnancy, common complications include hypertensive diseases and anemia. These complications significantly increase the probability of adverse pregnancy outcomes. Among them, anemia during pregnancy is a high-risk condition that not only affects the pregnant mother but also causes varying degrees of damage to the physical and mental health of the newborn. Additionally, it can lead to decreased resistance in the pregnant mother, posing a significant risk during childbirth. Therefore, regular blood examinations during pregnancy hold great significance. They allow us to identify the hemoglobin content in pregnant mothers in advance and facilitate timely control and treatment of anemia. This, in turn, helps prevent and mitigate adverse conditions. It is worth noting that the hemoglobin content of pregnant females may vary across different pregnancies due to differences in vitamin D levels. Hence, this paper primarily investigates the relationship between hemoglobin content and different pregnancies in pregnant females.