This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous (Gynae), Subject name: Gynaecology & Obstetrics
In a pregnant lady with hyperthyroidism , the safest drug to be used is - 
Select and explain. 
A. Propylthiouracil, B. Methimazole, C. Carbimazole, D. Lugols Iodine
A: Propylthiouracil
Answer: A: Propylthiouracil 
Explanation: Ans. is 'a' i.e., Propylthiouracil * Propylthiouracil is the DOC for hyperthyroidism in pregnancy.* Methimazole and carbimazole used in early pregnancy have been associated with esophageal and choanal atresia, aplasia cutis, and fetal agranulocytosis.* Graves' disease is the MC cause of hyperthyroidism in pregnancy.* Hashimoto's thyroiditis is the MC cause of hypothyroidism in pregnancy.* Complications associated with both hypo- and hyperthyroidism in pregnancy:1) Recurrent first trimester abortions2) IUGR3) Increased risk of preeclampsia4) Abruption5) Stillbirths, hydrop fetalis6) Preterm labor* Hypothyroidism is also associated with cretinism.