Regular ArticleFibrinogen levels in the late stage of twin pregnancy

•Blood fibrinogen levels were compared between twin and singleton pregnancies.•Fibrinogen decreased in late gestation of twin, but not of singleton pregnancy.•Fibrinogen in 3 weeks before delivery was lower in twin than singleton pregnancy.

IntroductionTwin pregnancy is a risk factor of complications, such as pregnancy-induced hypertension, venous thromboembolism, and postpartum hemorrhage, the pathogenesis of which may involve aberrations of the coagulation-fibrinolysis system.Materials and MethodsFibrinogen data for 129 and 1202 blood specimens from 84 and 902 women with twin and singleton pregnancies, respectively, at gestational week (GW) ≥ 32 were analyzed retrospectively. None of the 986 women developed complications in which blood fibrinogen levels may be altered. Thirty-six and 288 women with twin and singleton pregnancies were examined longitudinally, respectively.ResultsThe fibrinogen levels of 403 ± 63 and 403 ± 77 mg/dL at GW 32 - 33 and 34 - 35, respectively, decreased significantly to 366 ± 57 mg/dL at GW 36-37 in women with twins, while corresponding levels (422 ± 79, 420 ± 65, and 415 ± 64, respectively) and that at GW ≥ 38 (408 ± 60 mg/dL) did not change significantly in women with singleton pregnancies. The fibrinogen levels determined within 3 weeks before delivery were consistently and significantly lower in women with twin than singleton pregnancies. The fibrinogen levels were significantly inversely correlated with GW in women with twins (R = -0.36, P = 0.002), but not in those with singleton pregnancies.ConclusionsThe fibrinogen level of twin pregnancy decreases significantly and is significantly lower than that in singleton pregnancy in the last few weeks of pregnancy.