Hypofibrinogenemia is a rare disorder caused by the deficiency of fibrinogen in plasma. It can be either inherited or can be acquired following hepatic disorders, leukemias, or excessive consumption of clotting factors. It is typically diagnosed due to hemorrhage during a surgical or traumatic event.
Hypofibrinogenemia is a quantitative deficiency of fibrinogen which can be inherited or may develop secondary to a liver or bone marrow diseases, or excessive clotting factor utilization. Congenital hypofibrinogenemia is transmitted in an autosomal recessive manner  with the defective locus purported to be on chromosome 4 . Heterozygotes manifest this as hypofibrinogenemia while homozygotes present with afibrinogenemia .
As this is a rare disorder, there are very few reports of the clinical manifestations    . Patients with hypofibrinogenemia may present with mild bleeding but are typically asymptomatic. Although they have a higher tendency for bleeding from mucous membranes and deep tissues they are often detected only following bleeding during a traumatic or surgical episode  . Spontaneous bleeding, hemarthrosis, and life-threatening hemorrhage are rare  . Spontaneous and recurrent miscarriages and thrombotic events have also been reported in these patients .
Acquired hypofibrinogenemia is caused by either excessive loss of blood or exhaustion of clotting factors . Hypofibrinogenemia has been reported in patients with liver disease, disseminated intravascular coagulation (DIC), lymphoblastic leukemia , those receiving therapy with asparaginase  and in rare cases, following snake bites . Besides clinical manifestations of the underlying disorders, patients with hypofibrinogenemia will present with bleeding diathesis.
As with any bleeding disorder, clinical suspicion, detailed history and laboratory tests for coagulopathy form the mainstay of diagnosis. A family history is vital to diagnose congenital hypofibrinogenemia while a history of underlying liver or malignancy or snake bite is essential to indicate acquired causes of hypofibrinogenemia. During the physical examination, it is important to assess the severity of blood loss and identify features of hemorrhagic shock.
A complete blood count, liver function tests, and renal function tests are part of the routine workup. Standard laboratory tests for coagulation disorders such as prothrombin time (PT) and activated partial thromboplastin time (aPTT) may be normal in hypofibrinogenemia as small quantities of fibrinogen may be present to enable the formation of a clot. In some cases, PT and aPPT may be prolonged. Thrombin time is a more sensitive test for the diagnosis of hypofibrinogenemia compared to PT/ aPTT. Common tests to measure fibrinogen activity and concentration are the prothrombin time (PT)-derived fibrinogen assay and the Clauss assay  which is the gold standard test. These assays provide information quickly in an emergency. The ratio of fibrinogen antigen–to–clottable fibrinogen can be utilized to differentiate between dysfibrinogenemia and hypofibrinogenemia . In surgical situations, viscoelastic properties of fibrin and its formation are used for diagnosis in patients suspected of congenital or acquired hypofibrinogenemia .
Imaging studies such as brain computed tomography (CT) or magnetic resonance imaging (MRI) are indicated only if there are clinical manifestations suggestive of intracranial bleeding.