Your patient is a 27-year-old female patient with hypothyroidism taking levothyroxine that is newly married. Which of the following statements would you say to your patient regarding pregnancy and her medication?

a. "You should be careful about getting pregnant because levothyroxine is toxic to a fetus."
b. "You should decrease your dosage by 50% once your pregnancy is confirmed."
c. "Once your pregnancy is confirmed, increase your dosage of the medication by 50% percent."
d. "Because fetuses are unable to produce thyroid hormones during the first trimester, make sure to increase your dosage by 30% as soon as your pregnancy is confirmed to reduce the risk of decreased IQ and neuropsychological function in the fetus."