Prognosis

The individual prognosis in case of existing Factor 5 Leiden depends on whether the mutated gene is heterozygous, i.e. only once, or homozygous, i.e. twice. If the mutated gene has been passed on from mother and father to the child, i.e. if the affected person is homozygous, the probability of a blood clot occurring is 50 to 100 times higher.

The probability of developing a blood clot in this case is therefore very high.The probability for persons who are only heterozygously ill, i.e. who have mutated the gene only once, is only about 5 to 10 times higher than for non-affected persons. The disease is dangerous if a thrombus is very large and disrupts blood circulation in the leg, or if the blood clot breaks loose and an embolus develops, which can then trigger a pulmonary embolism or stroke. Recent studies suggest that individuals with Factor 5 disease may be more likely to have coronary artery disease.

Pregnancy with factor 5 Leiden

Pregnant women with a factor 5 condition should inform their gynaecologist and family doctor. During pregnancy the hormonal and so-called hemostatic conditions change. This means that due to the influence of hormones, factors that increase blood clotting are more active and at the same time factors that inhibit blood clotting are reduced.

It is suspected that especially the estrogen, which is present in higher concentrations during pregnancy, contributes to this. The tendency to blood clotting, the so-called thrombophilia, is therefore greatly increased. This mechanism could be evolutionary, possibly to reduce blood loss during pregnancy, especially shortly before birth, in order to protect mother and fetus.

However, this increases the risk of thrombosis in pregnant women. Studies have shown that the risk of thrombosis increases 5-6 times during pregnancy. Other risk factors can also increase the risk of thrombosis during pregnancy.

In pregnant women with factor 5 Leiden, the risk of thrombosis increases accordingly 7-16 times. Therefore, heparin treatment is generally recommended. Heparin increases the body’s own so-called antithrombin and thus reduces the risk of blood clotting.

Since the heparin does not pass through the membrane of the placenta, it cannot damage the fetus. Patients should be thoroughly informed and individually instructed by their doctor about heparin treatment. Once this was done, most of the pregnant women affected reported that self-treatment with heparin injections was problem-free.

There are many women who suffer from the gene modification Factor 5 and were able to fulfil their desire to have children without any problems. Many women do not even know or notice that they are affected. According to some studies, however, an increased risk of miscarriage is also suspected in women with Factor 5 Leiden.

Often, this genetic change is only detected when the women concerned do not have a child because of repeated miscarriages. However, under appropriate thrombosis prophylaxis with heparin, a Factor 5 condition does not generally impede the desire for children. Therefore, if the desire for a child exists, adequate treatment with medication is recommended, at best 3 months before the beginning of the pregnancy.

Since the gene modification Factor 5 Leiden is inherited autosomal dominant, it is inherited further. If both parents are affected, the child develops the homozygous form. If only one parent is affected, the child inherits the heterozygous form.

The increased miscarriage rate in women with factor 5 disease is controversially discussed. Different studies show different results. Some studies did not show a significant increase in miscarriages in women with factor 5 disease. In other studies, however, women with Factor 5 Leiden showed an increased incidence of recurrent miscarriages.