Establishment Of Reference Interval Of D-Dimer During Pregnancy And Its Application In Venous Thromboembolism And Postpartum Hemorrhage

Physiological changes during pregnancy such as hypercoagulability,venous stasis,and vascular damage increase the risk of venous thromboembolism(VTE)by 4 to 5 times compared to women who are not pregnant.Physiological changes during pregnancy including hypercoagulability provide material basis for rapid and effective hemostasis after birth,but it also easily leads to disseminated intravascular coagulation(DIC).Coagulation disorders and other complications associated with coagulopathy can cause DIC or primary postpartum hemorrhage(PPH).Both PPH and DIC are fatal and further exacerbate poor hemostasis.PPH is the most common type of major obstetric hemorrhage and remains one of the leading causes of maternal mortality in both developed and developing countries.Due to hypercoagulation during pregnancy,the reference intervals for coagulation in the non-pregnant population is not applicable for pregnant wome,in addition,the coagulation cascade during pregnancy is a progressive process.Therefore,a specific reference interval for evaluating the coagulation function of healthy pregnant women has to be established.Most of previous such studies were cross-sectional in design;thus,it was impossible to avoid the impact of differences in individual factors on the research results.Thus,a longitudinal study design would be more appropriate for this goal.The coagulation function index has important value in excluding the diagnosis of VTE and diagnosing DIC in the "non-special population".But in pregnant women,due to the lack of diagnostic limits,the use of the limit is greatly limited.Part one.Dynamic monitoring of coagulation function during pregnancy and establishing corresponding reference intervalsObjective Establishing the reference intervals of FIB?D-Dimer?PLT?PT?APTT?TT in each pregnancy.Methods A total of 691 healthy pregnant women who have antenatal caring all the time before delivering and 80 non-pregnant women of healthy childbearing age were collected.Monitoring coagulation parameters in the early pregnancy group,the middle pregnancy group,and the late pregnancy group.Analyzing whether age and parity are factors that affect the level of blood coagulation.The normal values of FIB?PLT?PT?APTT?TT were established by using bilateral percentile(P2.5-P97.5),the normal values of D-dimer were established by using percentile(P95).Results(1)There was no significant difference in FIB?D-Dimer?PLT?PT?TT level between the age<35 years group and the age? 35 year old group(P>0.05).(2)There was no significant difference in coagulation indexes between the number of births=1 and>2.(3)There were significant differences in FIB?D-Dimer?PLT?PT?APTT?TT levels in the first trimester,the second trimester and the thrid trimester of pregnancy(P<0.016).The levels of FIB and D-Dimer increased with the increase of gestational age;PLT,PT,APTT,TT levels decreased with the increase of gestational age.(4)The reference interval of FIB in first,second third trimester were 2.75?5.05g/L,3.18?5.08g/L,3.11?6.03g/L;the reference interval of D-Dimer in first,second,third trimester were?1.04ug/mL,?2.06ug/mL,?2.49ug/mL;the reference interval of PLT in first,second,third trimester were 134?315mmol/L,124?322mmol/L,116?320mmol/L;the reference interval of PT in first,second,third trimester were 11.60-14.60s,11.60-14.73s,11.32?13.80s;the reference interval of APTT in first,second,third trimester were 29.20?48.18s,29.04-46.48s,28.50-39.04s;and the reference interval of TT in first,second,third trimester were 14.2?20.10s,13.62-18.68s,13.92-18.57s.Conclusion(1)Age is no longer a factor affecting FIB?D-Dimer?PLT?PT?TT levels in pregnant women.(2)The number of births is no longer a factor affecting FIB?D-Dimer?PLT?PT?APTT?TT levels in pregnant women.(3)The levels of plasma D-dimer and FIB was positively correlated with gestational age,the levels of plasma PLT?PT?APTT and TT was negatively correlated with gestational age.(4)we established the plasma FIB?D-Dimer?PLT?PT?APTT?TT reference interval in pregnant women,which improved the application value of coagulation in pregnancy.Part two.The application value of D-dimer in venous thromboembolism and postpartum hemorrhage in pregnancyObjective To test the validity of D-dimer reference interval;to determine the role of D-dimer in venous embolism and postpartum hemorrhage.Methods The results of 8 cases of venous thromboembolism and 75 cases of postpartum hemorrhage complicated with coagulation disorders were used to validate the established normal values.ROC curve was used to evaluate and analyze the diagnostic efficiency of D-dimer levels in postpartum hemorrhage,and to determine the best cutoff value.Results The above reference intervals were used to evaluate the levels of D-Dimer in 8 cases of venous thromboembolism,the D-dimer was positive.The level of D-Dimer 2.65ug/mL as the best cutoff value prediction of postpartum hemorrhage.Conclusions(1)The D-dimer reference interval is efficient,However,large samples are needed for further verification.(2)The best cutoff value of D-dimer for diagnosis of postpartum hemorrhage was 2.65ug/mL.