Last update Aug. 26, 2022
Very Low Risk
Levothyroxine is the synthetic form of the hormone thyroxine (T4) secreted by the thyroid gland. It is indicated as therapy for congenital or acquired hypothyroidism and as a complement in thyrotropin-dependent thyroid cancer. Oral administration.
Maternal endogenous T4 is excreted naturally in breast milk (Vass 2022, Mallya 2018), but in very small amounts, insufficient to protect a breastfed baby with congenital hypothyroidism (van Wassenaer 2002, Mizuta 1983, Mallol 1982, Letarte 1980, Sato 1979, Sack 1977), although it might alleviate symptoms. (Bode 1978)
Administration of exogenous T4 does not significantly alter T4 levels in breast milk (Zhang 2013). The risk of using exogenous T4 is the same as that of an untreated euthyroid mother. (Hale)
No problems have been seen in infants whose mothers were taking T4. (Mungan 2016, Ito 1993, Caplan 1993)
Treatment with T4 in hypothyroid mothers does not pose a risk to the infant. Nursing mothers with hypothyroidism, even subclinical, should be treated with T4. (Alexander 2017)
Breastfeeding does not alter the infant's thyroid function or T4 levels. (van Wassenaer 2002, Franklin 1985, Abbassi 1980, Varma 1978)
Various medical societies and expert authors consider the use of this medication to be safe during lactation(Hale, Alexander 2017, Serrano 2015, Briggs 2015, Stagnaro 2011). Recommendations for Drugs in the Eleventh WHO Model List of Essential Drugs: compatible with Breastfeeding (WHO 2002). American Academy of Pediatrics: medication usually compatible with breastfeeding. (AAP 2001)
We do not have alternatives for Levothyroxine since it is relatively safe.
Suggestions made at e-lactancia are done by APILAM team of health professionals, and are based on updated scientific publications. It is not intended to replace the relationship you have with your doctor but to compound it. The pharmaceutical industry contraindicates breastfeeding, mistakenly and without scientific reasons, in most of the drug data sheets.
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Thank you for helping to protect and promote breastfeeding.
e-lactancia is a resource recommended by Academy of Breastfeeding Medicine - 2012 of United States of America
Would you like to recommend the use of e-lactancia? Write to us at corporate mail of APILAM