Hypothyroidism in pregnancy is defined as the presence of an elevated thyroid stimulating hormone during gestation, affecting 2% to 3% of the population. Overt hypothyroidism is diagnosed by a decreased FT4, while patients with a normal FT4 are considered to have subclinical disease. Poorly controlled disease is associated with both pregnancy complications and developmental delays in the offspring. Treatment consists of replacement with levothyroxine and regular monitoring. Most pregnant women will require an increase in their dosing from 25% to 30%. While treatment for SCH remains controversial, current recommendations do not support universal screening of low-risk women during pregnancy.