This TSH reflects hypothyroidism. This may increase the risk of miscarriage and other pregnancy problems, including developmental delay in the child. Immediate intitiation of thyroid hormone (levothyroxine) is necessary at a full replacement dose (usually 2mcg/pound, sometimes more for pregnancy) and recheck levels to confirm it is not a lab error. Would discuss with your OBGYN and consider endocrine consult as well. Sometimes we send women to "high-risk" OB for more thorough evaluation in these cases.
CORRECTION -- the full replacement dose is usually 2mcg/kg (or 0.7mcg/pound) for normal weight patients -- sorry for the wrong weight unit!