Value of Neutrophil-to-Lymphocyte Ratio and Platelet-to-Lymphocyte Ratio for Predicting Preeclampsia During Pregnancy

  Objective  To investigate the changes of neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) in women with normal pregnancy women and pregnant women with preeclampsia (PE) and the value of using NLR and PLR in the first trimester to predict PE.

  Methods  We retrospectively collected the clinical data of 485 pregnant women (97 had PE and 388 were of normal pregnancy) who were admitted to West China Second University Hospital and had their babies delivered there between January 1 and December 31, 2016 and 30 healthy women who were not pregnant and who had physical examination at the hospital over the same period. The subjects' NLR and PLR were calculated and compared. Logistic regression analysis was done to study the risk factors of PE, and the receiver operating characteristic curves were used to assess the value of using NLR and PLR in the first trimester to predict PE.

  Results  There was no significant difference in NLR or PLR between the PE group and the normal pregnancy group in the first, second and third trimesters. Compared with that of the normal non-pregnant group, the NLR of the PE group and the normal pregnancy group started to rise in the first trimester, reached the maximum in the second trimester, and decreased in the third trimester; PLR started to decrease in the second trimester and reached the lowest level in the third trimester, exhibiting significant differences (P<0.05). In the three trimesters, NLR and PLR were not associated with the severity of PE, maternal age, or pre-pregnancy BMI. The predictive model combining factors including pre-pregnancy obesity, advanced maternal age, and nulliparity showed an area under the curve (AUC) of 0.84 for predicting PE. When NLR in the first trimester or PLR in the first trimester were added to the combined model of pre-pregnancy obesity, advanced maternal age, and nulliparity, the AUC subsequently derived were both 0.85.

  Conclusion  NLR and PLR are not independent influencing factors of PE and cannot improve the predictive value for PE.