Antenatal Steroids Before Elective Caesarean Section : Impact on Coagulation, Fibrinolytic System, and Other Haematological Parameters.

Corticosteroid administration before anticipated preterm birth is one of the most important antenatal therapies available to improve newborn outcomes. A single course of corticosteroids is recommended for pregnant women between 28 weeks and 40 weeks of gestation who are at risk of preterm delivery within 7 days, including for those with ruptured membranes and multiple gestations (1). The administration of antenatal corticosteroids to women who, at risk of imminent preterm birth, is strongly associated with decreased neonatal morbidity and mortality (2). Neonates whose mothers received antenatal corticosteroids have significantly lower severity, frequency, or both, of respiratory distress syndrome, intracranial haemorrhage, necrotizing enterocolitis, and death, compared with neonates whose mothers did not receive antenatal corticosteroids, Betamethasone and dexamethasone are the most widely studied corticosteroids, and they generally have been preferred for antenatal treatment to accelerate foetal organ maturation (3). Both cross the placenta in their active form and have nearly identical biologic activity. Both lack mineralocorticoid activity and have relatively weak immunosuppressive activity with short-term use (4).

Increased levels of haemostatic factors, including factor VII, factor VIII, factor XI, fibrinogen, soluble CD40 ligand, and von Willebrand Factor VWF have been associated with venous and arterial thrombotic events. Similarly, impaired thrombolysis, reflected by an increase in Plasminogen activator inhibitor-1 PAI-1 levels, has been associated with adverse cardiovascular events. Although there are no previous in vivo studies in humans demonstrating that glucocorticoids directly affect haemostasis, there is in vitro and epidemiologic evidence of this phenomenon (5). In cultured human and animal cell lines, glucocorticoids increase production of von Willebrand Factor (VWF), endothelin, and PAI-1. Two studies have demonstrated dexamethasone-mediated increases in PAI-1 in cultured human adipose tissue. In patients with Cushing syndrome, elevated levels of VWF, PAI-1, thrombin-antithrombin and plasmin-antiplasmin complexes and factor VIII may resolve after curative surgical treatment. Similarly, altered levels of haemostatic factors have been reported in patients receiving exogenous glucocorticoids. The potential impact of glucocorticoids on thrombosis is clinically relevant (6). Therefore, we sought to determine the effects of antenatal glucocorticoid administration on haemostatic factors in pregnant females.