Sarita, a 30 year old woman develops a deep vein thrombosis in her left calf on fourth post operative day following cesarean section done for fetal distress. The patient is started on heparin and is scheduled to begin a 6 weeks course of warfarin therapy.The patient is a devoted mother who wants to breast feed her baby.What is the advice which is given to the patient:
Remember:

Warfarin is contraindicated in the first trimester of pregnancy as it can lead to contradi syndrome comprising of microcephaly, optic atrophy, nasal hypolplasia and chondrodysplasia punctate.It can also lead to IUGR, abortions and IUD.
But warfarin is absolutely safe during lactation as an extremely minute quantity of it is excreted in breast milk.
Patient may continue breast feeding at her own risk.
Patient should breast feed her baby only if her INR is at <2.5
Patient can breast feed her baby after 6 weeks course of warfarin is over
Warfarin is not a contraindication for lactation.