Oral contraceptives increase the risk of blood clots in women with factor V Leiden, states the National Institutes of Health. Because approximately 5 percent of Caucasian women have the condition, some researchers suggest that women have their doctors screen for factor V Leiden before prescribing oral contraceptives, according to the U.S. National Library of Medicine. Doctors can detect the condition with a blood test.
Other medications that increase the likelihood of blood clots include estrogen replacement hormones, explains Mayo Clinic. Other risk factors include injury, surgery, obesity and smoking. Long periods without movement, such as during bed rest and long trips in cars or on airplanes, can impede circulation and cause clotting. Patients who must be still for long periods should increase water intake, abstain from alcohol and move around whenever possible.
Factor V Ledien is a genetic mutation of the factor V gene, and patients with a family history of the condition have a higher risk of carrying the mutated gene, according to Mayo Clinic. Treatment includes prescription anticoagulant medications, such as heparin and warfarin, to thin the blood. Newer oral thinners, such as dabigatran, rivaroxaban and apixaban, are easier for clinicians to dose, but there is limited research on their effects on pregnant women, as of 2015.