Guidelines for anticoagulant use in mechanical valve pregnant woman

Management of mechanical heart valves in pregnancy is still a clinical dilemma for women and clinician, because of pregnancy itself considers pro thrombotic state and the options available for management of this case still Subject to benefit risk choice.

Warfarin is the most effective anticoagulant used in patient with mechanical valves, but Warfarin exposure during pregnancy causes a recognized pattern of major congenital malformations (warfarin embryopathy), fetal hemorrhage, and an increased risk of spontaneous abortion and fetal mortality.

Warfarin is category X in pregnancy, and category D in pregnant with mechanical heart valves.

There is three major ways to manage this case according to benefit risk consideration:

1. Use warfarin throughout the pregnancy, decreases thrombotic events, but increase embryopathy events.
2. Use of LMWH or heparin from the start of gestational week 6 through the end of gestational week 12 and again at term may lessen the risk to the fetus of adverse outcome.
3. Use of LMWH or heparin throughout the pregnancy, increases thrombotic event, with no embryopathy events.

All options can be adjusted according to level of risk of patient, and the physician must explain to patient the regime he will use.

If  LMWH is used, Anti Xa activity must be followed up after 4 hrs of administration, physician can choose from those guidelines according of the case.