To explore the relationship of serum calcium (Ca²⁺), 25-hydroxyvitamin D (25-(OH)-D), and D-dimer (D-D) with fetal growth and development in patients with hypertensive disorder complicating pregnancy.

A total of 143 patients with hypertensive disorder complicating pregnancy who received cesarean section at the Affiliated Hospital of Jining Medical University from January 2020 to October 2021 were selected as an observation group. Their mean age was (29.3±2.7) years. According to the severity of the disease, the patients were further divided into a gestational hypertension subgroup (43 cases), a mild preeclampsia subgroup (44 cases), a severe preeclampsia subgroup (38 cases), and an eclampsia subgroup (18 cases). In addition, 143 normal pregnant women who underwent caesarean section at our hospital during the same period were selected as a control group, and their mean age was (28.8±2.9) years. Serum Ca²⁺, 25-(OH)-D, and D-D levels, placental weight, and fetal growth and development were measured and compared in all subjects. Pearson correlation analysis was used to analyze the relationship of serum Ca²⁺, 25-(OH)-D, and D-D levels with fetal production and development.

The levels of serum Ca²⁺ and 25-(OH)-D, placental weight, fetal weight, head circumference, biparietal diameter, abdominal circumference, and body length in the observation group were all lower than those in the control group (P＜0.05 for all), and the level of D-D was higher than that in the control group (P＜0.05). With the increase of the severity of the disease, the levels of serum Ca²⁺ and 25-(OH)-D, placental weight, fetal weight, head circumference, biparietal diameter, abdominal circumference, and body length of the patients decreased gradually (P＜0.05 for all), while the level of D-D increased gradually (P＜0.05). Pearson correlation analysis showed that D-D was negatively correlated with placental weight, fetal head circumference, biparietal diameter, abdominal circumference, body length, and body weight (r=-0.518, -0.453, -0.501, -0.366, -0.438, and -0.492, respectively, P＜0.05 for all), while serum Ca²⁺ and 25-(OH)-D were positively correlated with placental weight, fetal head circumference, biparietal diameter, abdominal circumference, body length, and fetal weight (Ca²⁺: r=0.408, 0.326, 0.402, 0.411, 0.435, and 0.473; 25-(OH)-D: 0.487, 0.394, 0.359, 0.376, 0.420, and 0.502, respectively, P＜0.05 for all).

The levels of serum Ca²⁺ and 25-(OH)-D in patients with hypertensive disorder complicating pregnancy decrease, while the level of D-D increases. All of them are involved in the occurrence and development of hypertensive disorder complicating pregnancy, and can also affect the growth of placenta and fetal development.