Understanding Factor V Leiden and Lovenox After Miscarriage

Question
Dear Dr. Rappaport,
I am a young, healthy 47 year old, have 2 children, 24 & almost 20 (daughters), 2 grandchildren (3 & 5), and a wonderful new husband, also 47 (a personal trainer and also very young and healthy!).
A year ago we were all pleasantly surprised with the news that I was pregnant. Unfortunately, at 5 weeks I miscarried. Dave and I decided it was truly what we wanted and continued to try to become pregnant again with no success. After extensive research we made the decision to go IVF with a donor egg to ensure the baby will not have chromosomal abnormalities - as we know the risks of using my old eggs to conceive.
The fertility specialist did extensive blood work and found I am homozygous Factor V Leiden. I am asymptomatic - have never had a blood clot or any thing close and have had many occasions that could have produced this - 3 pregnancies, birth control pills for many years, yet never a problem. My Hematologist has recommended that I be on Lovenox 2 weeks before the embryo transfer and then all through my pregnancy. My concern here is the actually delivery. I am having 2 embryos transfered - pretty good chance this will produce twins - will this mean I will most likely have to have a c section? Will being on the Lovenox cause me to more likely to hemmorage? I realize the importance of adding the Lovenox as I will be taking so much extra estrogen, but I worry about my blood becoming too thin. I have also read that I couldn't have an edipural if I'm on Lovenox. I went natural with my first 2 - I plan on taking advantage of the pain-killers available this time!
Please accept my apologies for the length of my question (I tend to be long-winded!), and my thanks for any light you can shed on this!
Ruthanne

Answer
Once you accept the necessity for the use of Levonox during pregnancy you will realize that the only alternative is the use of Heparin. Levonox works better and is easier to take and to monitor. I have many patients on Levonox during pregnancy for similar problems such as yours. Multiple gestations are not a contradiction to its use. The reason for the trepidations in the use of epidurals is with low platelets. Levonox use during pregnancy will not cause undue anxiety or too much thinning of your blood and you shoujld be able to carry to term without fear of the clotting disorder. Of course you should always work with a hematologist in conjunction with your obstetrician or perinatologist.