How to manage hypothyroidism during pregnancy?
Q: I am in my 7th month of pregnancy. I have hypothyroidism and am taking Eltroxin 100 mcg. My recent thyroid profile shows - FT3 - 1.6 (1.2 - 4.2 PG/DL); FT4 - 0.6 (0.8 - 2.0 NG/DL); TSH - 0.9 (0.4 - 6.0 MIU/ML); My doctor has increased my dosage to 150 mcg. Is it enough? Is my FT4 too low? Will hypothyroidism affect my child? Will my Eltroxin dosage be reduced after delivery?
A:Women need more thyroid hormone during pregnancy and, unlike normal women; those with hypothyroidism are unable to increase thyroidal Thyroxine hormone (T4 and T3) secretion. Women may need higher doses of Thyroxine (tablet) during pregnancy may need upto 45 % more than pre-pregnancy levels. We recommend more frequent monitoring. The increase in thyroxine dose begins at about 8 weeks and peaks by week 16 of pregnancy. After a woman’s new optimal T4 dose is established, the frequency of blood monitoring can be decreased to approximately once every trimester. Serum (blood test) TSH levels measured every four weeks until the TSH becomes normal, thereafter less frequently. After delivery, a woman’s dose of Thyroxine will need to be readjusted and most often patients will go back to the pre pregnancy dose. Women with hypothyroidism whose Thyroxine (T4) levels are carefully regulated during pregnancy (as it seems in your case) have normal children. You will need another test (TSH and FT4) 4 weeks after you have increased the dose of thyroxine and then again 4 weeks after delivery.