the eyes is also affected by warfarin. Microphthalmia; abnormally small eyes, telecanthus; abnormally far apart eyes and strabismus; misaligned or crossed eyes are common signs of fetal warfarin syndrome. The appearance of an ectopic lacrimal duct, where the tear duct protrudes laterally onto the eye has also been noted. Bodily features Whole body skeletal abnormalities are common in fetal warfarin syndrome. A generalized reduction in bone size causes rhizomelia; disproportionally short limbs, brachydactyly; short fingers and toes, a shorter neck, short trunk, scoliosis; abnormal curvature of the spine and stippled epiphyses; malformation of joints. Abnormalities of the chest: either pectus carinatum; a protruding sternum, or pectus excavatum; a sunken sternum form an immediately recognizable sign of fetal warfarin syndrome. Congenital heart defects such as a thinned atrial septum, coarctation of the aorta, patent ductus arteriosus; a connection between the pulmonary artery and aorta occur in 8% of fetal warfarin syndrome patients. Situs inversus totalis, the complete left-right mirroring of thoracic organs, has also been observed CNS Defects of the central nervous system can lead to profound intellectual disabilities. Fetal warfarin syndrome can lead to microcephaly; an abnormally small head, hydrocephaly; increased ventricle size and CSF volume, and agenesis of the corpus callosum. These defects contribute to the appearance of significant intellectual disability in 31% of fetal warfarin syndrome cases. Hypotonia, whole body muscle relaxation, can appear in newborns with severe nervous deficits. Atrophy of the optic nerve can also cause blindness in fetal warfarin syndrome. Physiological Inhibition of coagulation and resultant internal bleeding can cause too few red blood cells to be present in the bloodstream and low blood pressure in newborns with fetal warfarin syndrome. Low hemoglobin levels can lead to partial oxygen starvation, a high level of lactic acid in the bloodstream, and acidosis. Prolonged oozing of fluid from the stump of the cut umbilical cord is common. Cause Fetal warfarin syndrome appears in greater than 6% of children whose mothers took warfarin during pregnancy. Warfarin has a low molecular weight so can pass from the maternal to fetal bloodstream through the tight filter-like junctions of the placental barrier. As the teratogenic effects of warfarin are well known, the medication is rarely prescribed to pregnant women. However, for some patients, the risks associated with discontinuing warfarin use may outweigh the risk of embryopathy. Patients with prosthetic heart valves carry a particularly high risk of thrombus formation due to