Factor V Leiden & Pregnancy: Understanding the Risks & What to Expect

Question
I am 21 & have had 3 miscarriages(early on); I am 17 weeks pregnant now(LMP-July 14, 2004)This is my longest pregnancy.i just found out that I have Factor 5 Leiden mutant (Heterozygous) and this is the cause for my miscarriages. What I do know of this problem is that it has to do with my blood clotting...All I want to know is what this mean for my pregnancy? Is there any defects this my cause the baby? What is this factor 5 and is this a really big problem for me and my baby? Do I have to worry?

Answer
With Factor 5 Leiden, you have to worry about thrombotic phenomena during pregnancy. There is a higher risk of thrombosis with those that are homozygous for Factor V Leiden than those taht are heterozygous for Factor V Leiden. (80 fold versus 5-10 fold). If you do develop thrombosis, there is an increased risk during the pregnancy of miscarriage, preecclampsia (pregnancy induced hypertension), IUGR (intrauterine growth restriction), and placental abruption, but there do not appear to be any problems for the baby if it is born alive. Depending on your specific case, you may or may not have been offerred Heparin prophylaxis during pregnancy. I do not know enough about your individual case to comment on that. Ask your obstetrician if Heparin would be a good idea. There are some authors that do not think that there is anything to worry about, while others are more skeptical.