Objective To investigate the correlations of CALLY index in early pregnancy with the onset and severity of preeclampsia.

Methods A total of 987 pregnant women were prospectively enrolled as study subjects, with 42 lost during follow-up, resulting in a final inclusion of 945 subjects. Based on the occurrence and severity of preeclampsia during follow-up, the pregnant women were divided into preeclampsia group (n=47), severe preeclampsia group (n=49), and normal group (n=849). General information and laboratory test results were collected from all pregnant women, and the CALLY index was calculated. The Pearson correlation analysis was used to explore the correlation between CALLY index and severity of preeclampsia (mean arterial pressure); the receiver operating characteristic (ROC) curve was plotted to analyze the predictive efficacy of each indicator for preeclampsia; Cox regression analysis was used to explore the influencing factors for the onset of preeclampsia.

Results The mean arterial pressure and 24-hour urine protein levels were higher in the severe preeclampsia group than those in the preeclampsia group and normal group, and higher in the preeclampsia group than those in the normal group (P < 0.05). The CALLY index was lower in the severe preeclampsia group than in the preeclampsia group and normal group, and lower in the preeclampsia group than in the normal group (P < 0.05). Pearson correlation analysis showed a negative correlation between CALLY index and mean arterial pressure (r=-0.571, P < 0.001). The ROC curve showed that the area under the curve (AUC) of CALLY index for predicting preeclampsia was 0.941 (95%CI, 0.900 to 0.981). Multivariate Cox regression analysis showed that an increased CALLY index was an independent protective factor for the onset of preeclampsia (HR=0.185, 95%CI, 0.092 to 0.374, P < 0.001).

Conclusion The CALLY index is negatively correlated with the severity of preeclampsia and is an independent influencing factor for the onset of preeclampsia, which can be used as an auxiliary indicator to assess the onset and severity of preeclampsia in pregnant women.