There is a recurrence rate of 30% in people who have had an earlier incidence of pulmonary embolism. This rate has been calculated on people who have not had any triggers to cause the embolism.
in your case, even in the non-pregnant state the chances of recurrence are 30%. With a trigger like pregnancy the risks are much higher.
The best prevention of a repeat embolism is warfarin. But you cannot take Warfarin during pregnancy because it crosses the placenta to pass to the fetus and may be toxic to the fetus.
Your doctor's are right - you should not attempt another pregnancy.
I hope this helps.
If you have put on weight since the previous pregnancies, or if you had been more at rest during the third pregnancy then these could be the causes of the embolism. But many embolisms occur spontaneously with no prredisposing factors.
Zoloft does not directly cause embolism. But your taking Zoloft suggests that you had been treated for depression, and being depressed could cause you to be less active than normal.
Yes, you can take heparin injections. But heparin can cause uteroplacental bleeding leading to miscarriage, preterm labor or even fetal death. It can also cause thrombocytopenia (lowered level of platelets) and osteoporosis. You will also need very close monitoring throughout the pregnancy.
I do not feel that these risks of heparin should be taken unless you are really desperate.
Being more active and wearing dvt stockings will help to some extent. But you must remember that pregnancy is a very strong predisposing factor for embolism.
Once an embolism has occured, the main prevention is by taking warfarin or heparin. Being active also helps.
You will have to discuss the risks very thoroughly with the obstetrician who will be in charge of you during the pregnancy. You will need to be monitored more regularly than a normal pregnancy with repeated ultrasounds and blood tests. You should try to get pregnant only if the obstetritian has gone over all your previous records and allows you to get pregnant. You will need very quick and early care should an embolism occur. More than 90% of patients die of an embolism before it is diagnosed.
Please discuss your wish to get pregnant with your obstetritian before you decide anything.
A inferior vena cava filter can be used to prevent bloodclots from reaching the heart or lungs. But these are not without risks either. The filter may move from its location, may injure nearly organs and being a surgical procedure, not without risks of infection.
Please discuss the options with your Obgyn if you are thinking of getting pregnant again.