The Discussion Of Plasma D-dimer Reference Range In Women During Pregnancy And Puerperium In The Area Of Lanzhou

Objective:By collecting plasma D-dimer values from healthy pregnant and puerperal women in Lanzhou,observing the changes of plasma D-dimer levels during pregnancy and puerperium,understanding the influence of maternal and fetal-related factors on plasma D-dimer levels,establishing the reference range of plasma D-dimer in women during pregnancy and puerperium in Lanzhou and exploring the value of the above reference range in pregnancy-related thrombophilia,with a view to guide the management and anticoagulation treatment of pregnant and puerperal women in the future.Methods:According to the inclusion and exclusion criteria of this study,the medical history data of pregnant and puerperal women who underwent prenatal examination and delivery at the Second Hospital of Lanzhou University were collected from September2021 to September 2022,including the normal pregnancy group:early pregnancy group(≤13⁺⁶weeks),n=203,middle pregnancy group(14～27⁺⁶weeks),n=175,late pregnancy group 1(28～33⁺⁶ weeks),n=345,late pregnancy group 2(34-41⁺⁶weeks),n=493;normal postpartum group:24-48 hours postpartum group,n=496;42 days postpartum group,n=118;disease group:10 cases of lower limb venous thrombosis and1 case of pulmonary embolism.In the morning,pregnant and puerperal women were collected fasting elbow vein blood in the outpatient or inpatient department.The plasma D-dimer values were measured by immunoturbidimetry and statistically analyzed:（1）to observe the changes of plasma D-dimer levels during pregnancy and puerperium;（2）to understand the influence of maternal and fetal factors on plasma D-dimer levels;（3）to establish the reference range of plasma D-dimer levels in healthy pregnant and puerperal women in Lanzhou and then randomly select 20 experimental subjects in each group according to the inclusion and exclusion criteria of the reference to verify the reference obtained by this study;（4）to compare the D-dimer levels in the disease group with the above reference range,exploring the value of the above reference range in pregnancy-related thrombophilia.Results:1.There were significant differences in plasma D-dimer level between normal pregnancy groups（P<0.001）,and the plasma D-dimer levels were positively correlated with gestational week（r_s=0.689,P<0.001）.Plasma D-dimer level at 42 days postpartum were much lower than at 24-48 hours postpartum,and the difference was statistically significant（P<0.001）.2.There was no statistically significant difference in plasma D-dimer level between the age<35 years group and the age≥35 years group during pregnancy and puerperium.（P>0.05）.3.There was no statistically significant difference in plasma D-dimer levels between the number of pregnancies=1 and≥2,the number of births=0 and≥1during pregnancy（P>0.05）.4.In normal postpartum group,the level of plasma D-dimer after cesarean delivery was higher than that after vaginal delivery and the difference was statistically significant（P<0.001）.5.There was no significant difference in plasma D-dimer level of 24-48 hours after delivery between different indications of cesarean delivery（P>0.05）.6.In the third trimester of pregnancy,the plasma D-dimer level of the fetal length≥50cm group was greater than the fetal length<50cm group and the fetal weight≥3000g group was greater than the fetal weight<3000g group,the difference was statistically significant（P<0.05）,and the fetal length and weight positively correlated with plasma D-dimer level（r_s=0.089,P<0.05;r_s=0.169,P<0.001）.7.Using the reference range obtained in this study to evaluate the plasma D-dimer levels of 10 patients with lower extremity venous thrombosis and 1 patient with pulmonary embolism,and the results were all positive.Conclusion:1.The plasma D-dimer levels in pregnant women are higher than in the general population,and the greater the gestational week,the higher the plasma D-dimer level,the plasma D-dimer levels gradually decreases in puerperium.2.In the subjects included in this study,the mode of delivery had an effect on postpartum plasma D-dimer levels,with those who delivered by cesarean section having greater plasma D-dimer levels than those who delivered vaginally,while indication for cesarean section has no effect on postpartum plasma D-dimer levels.3.Fetal length and weight have an effect on plasma D-dimer levels;the greater the fetal length and weight,the higher the plasma D-dimer level.4.The reference range of plasma D-dimer of healthy pregnant women and puerperal women in Lanzhou was:in the early pregnancy group(≤13⁺⁶weeks)<0.97mg/L;in the middle pregnancy group(14～27⁺⁶weeks)<1.58 mg/L;late pregnancy group 1(28～33⁺⁶ weeks)<2.12 mg/L;late pregnancy group 2(34-41⁺⁶weeks)<4.18mg/L;24-48 hours after vaginal delivery<4.07 mg/L;24-48 hours after cesarean delivery<4.57 mg/L,and the verification passed.