Levothyroxine is also known as: Eltroxin, Euthyrox, Eutroxsig, Evotrox, L Thyroxine Roche, Levo-T, Levotabs, Levotec, Levothroid, Levothyrox, Levoxyl, Novothyrox, Oroxine, Synthroid, Tirosint, Unithroid Levothyroxine Pregnancy Warnings Use is considered acceptable. AU TGA pregnancy category: A US FDA pregnancy category: A.
See references Levothyroxine Breastfeeding Warnings -In one study, levothyroxine (thyroxine) levels in 70 milk samples from 20 euthyroid women 17 to 39 days after delivery were determined by gas chromatography-mass spectrometry (GCMS ).
RESULTS : In all patients, the serum thyrotropin level increased during pregnancy. The mean - SE) serum free-thyroxine index decreased from 111.0 /- 5.8 before pregnancy to 86.5 /- 5.2 during pregnancy (normal, 64 to 142; P less than 0.05 and the mean serum thyrotropin level increased from 2.0 /- 0.5 mU per liter before.
-The dosage requirement of this drug may be increased in the postpartum period compared to prepregnancy requirements patients with Hashimoto's thyroiditis. See references References for pregnancy information Pharmaceutical Society of Australia "APPG uide online.
"UK Summary of Product Characteristics." O
Although the effects of this modest level of hypothyroidism are not known, we think it prudent to monitor thyroid function throughout gestation and after delivery and to adjust the thyroxine dose to maintain a normal serum thyrotropin level.
Management of women with hypothyroidism during pregnancy requires specialist supervision. In the postpartum period thyroxine requirements return to the pre-pregnancy levels. Notes: during the first trimester of pregnancy maternal thyroid hormone is responsible for normal foetal neurological development (till the foetal thyroid gland becomes active).
The mean postpartum thyroxine dose was decreased to 0.117 /- 0.011 mg per day (P less than 0.01 as compared with the dose during pregnancy). CONCLUSIONS : Our results indicate that the need for thyroxine increases in many women with primary hypothyroidism when they are pregnant, as reflected by an increase in serum thyrotropin concentrations.
Since elevations in serum TSH may occur as early as 4 weeks gestation, pregnant women taking this drug should have their TSH measured during each trimester. An elevated serum TSH level should be corrected by an increase in the dose of this drug.
"Thyroid hormones in human milk and their influence on thyroid function of breast-fed babies." Pediatr Res 17 (1983 468-71 "Product Information. Synthroid (levothyroxine)." Abbott Pharmaceutical, Abbott Park, IL. Jansson L, Ivarsson S, Larsson I, Ekman R "Tri-iodothyronine and thyroxine in human milk." Acta Paediatr Scand 72 (1983 703-5 Hahn HB, Spiekerman AM, Otto R, Hossalla.
Australian prescription products guide online. Available from: URL: p." (2006 "Product Information. Synthroid (levothyroxine)." Abbott Pharmaceutical, Abbott Park, IL. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0. References for breastfeeding information Moller B, Bjorkhem I, Falk O, Lantto O, Lafsson A "Identification of thyroxine in human breast milk by gas chromatography-mass spectrometry." J.
So there is an increased need of maternal thyroxine in pregnant women (4) due to the increased demand of maternal thyroid hormone, the requirement for iodine is also increased during pregnancy.
The main causes of hypothyroidism during pregnancy are: iodine deficiency - affects more than 1.2 billion people chronic autoimmune thyroiditis - when iodine intake is adequate (2) During pregnancy thyroxine requirements may increase by up to 50; thyroid function tests are undertaken each trimester.
-If this drug is required by the mother, it is not a reason to discontinue breastfeeding. -This drug is recommended treatment for postpartum thyroiditis and tapering of the dose should be avoided when a woman is breastfeeding.
Because of high thyrotropin levels, the thyroxine dose was increased in 9 of the 12 patients. Among the three patients who did not require an increased thyroxine dose were two with low serum thyrotropin levels before pregnancy, suggesting excessive replacement at that time.
BACKGROUND AND METHODS : Women with hypothyroidism have been thought not to require an increase in thyroxine replacement during pregnancy. To evaluate the effects of pregnancy on thyroxine requirements, we retrospectively reviewed the thyroid function of 12 women receiving treatment for primary hypothyroidism before, during, and after pregnancy.
Women with autoimmune thyroiditis who were euthyroid early in pregnancy, are at an increased risk of developing hypothyroidism as the pregnancy progresses (1) Reference.
Both overt and subclinical hypothyroidism is associated with significant risk to both the mother and the developing foetus (1). The prevalence of overt hypothyroidism during pregnancy is estimated to be subclinical hypothyroidism during pregnancy is estimated to be around 23.
-Thyroid hormones cross the placental barrier to some extent as evidenced by levels in cord blood of athyreotic fetuses being approximately one-third maternal levels. Transfer of thyroid hormone from the mother to the fetus, however, may.
Therefore, the possibility of fetal harm appears remote. This drug should not be discontinued during pregnancy and hypothyroidism diagnosed during pregnancy should be promptly treated. -Hypothyroidism during pregnancy is associated with a higher rate of complications, including spontaneous abortion, pre-eclampsia, stillbirth and premature delivery.