Coagulation Parameters in Singleton and Twin Pregnancies

Background: Coagulation and fibrinolytic systems affect maternal and fetal health in both singleton and twin pregnancies. Any abnormal deviation can have fatal implications like pre-eclampsia, venous thromboembolism, anemia, fetal asphyxia and haemorrhage.
Objective: We aimed to assess changes in coagulation and fibrinolytic systems throughout pregnancy (singleton and twin) through comparing the parameters for coagulation: Fibrinogen (Fib), activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT) and D-dimer (DD).
Subjects and methods: An interventional study was conducted on 300 pregnant women (194 singleton and 106 twin pregnancies), who were randomly recruited from 2019 to 2024 from the Outpatient Clinic of the General Military Hospital in Alexandria, Egypt. During routine antenatal care, coagulation parameters (Fib, APTT, PT, TT and DD) were analyzed during all trimesters of pregnancy.
Results: The mean maternal age showed no significant difference, whereas a twin pregnancy was significantly higher (P=0.000*) in primigravida (65.1%) than in multipara (34.9%). All coagulation parameters (TT, Fib, APTT and PT) showed significantly higher trends with increasing gestation in both singleton and twin pregnancy except for TT, which was the only coagulation parameter that did not show any significant difference (P=0.856).
All parameters of coagulation (TT, Fib, APTT and PT) showed significantly higher trends in twin pregnancies compared to singleton pregnancies in the first and final trimesters of pregnancy. In the second trimester of pregnancy Fib and TT showed significantly higher trends (P= 0.000*) in twin pregnancies than singleton pregnancies, whereas APTT and PT showed no significant differences (P= 0.017 and P= 0.699 respectively). D-dimer revealed significantly higher (P= 0.001*) trends in twin pregnancies compared to singleton pregnancies in the final trimester of pregnancy.
Conclusion: With increasing gestation, almost all coagulation parameters showed significantly higher trends in singleton and twin pregnancies. Individual trends in twin pregnancies were significantly higher in almost all coagulation parameters compared to singleton pregnancies.