Last update Nov. 23, 2019

Congenital Hypothyroidism

Very Low Risk

Safe. Compatible. Minimal risk for breastfeeding and infant.

Hypothyroid infants may have feeding difficulties due to sucking and swallowing problems due to neurological retardation and macroglossia (large tongue) (Lawrence 2016 p 498). Because of this and difficulty in gaining weight, they are more at risk of having breastfeeding suspended.

Breastfeeding is the best option for a hypothyroid infant (Lawrence 2016 p 498, Lawrence 2013).

Although breastmilk has significant amounts of thyroid hormone (Sack 1979 and 1977, Varma 1978) and breastfed infants have higher plasma concentrations of thyroid hormones than non-breastfed infants (Hahn 1983), breastmilk is not sufficient on its own to treat hypothyroidism (Sack 1979, Varma 1978).

The treatment consists in the daily oral administration of synthetic thyroid hormone, levothyroxine (LT4), either in the form of crushed tablets or the new liquid forms.

The intestinal absorption of the thyroid hormone decreases discreetly with the calcium in the milk (Chon 2018) so it is usually recommended that it be administered whilst fasting, half an hour before eating (Bach 2009).

But this recommendation is not applicable to small breastfed infants. Keep in mind that cow's milk, on which the 2018 Chon article is based, contains 1,300 mg/L of calcium versus 330 mg/L in breastmilk.

In addition, the amount of LT4 to be administered depends on the analytical results of the infant, increasing or decreasing the dose depending on the TSH and T4 results of the infant.

Several medical associations, experts and expert consensus in pediatric endocrinology recommend mixing LT4 with water or "breastmilk" for administration (Castilla 2015, Lèger 2014, GPC 2014, Brown 2012, Grob 2012).

The bioavailability of LT4 liquid preparations does not decrease with the simultaneous intake of food, so it would not be necessary to carry out a period of fasting with this type of preparations (Pirola 2018, Marina 2017, Ianiro 2014, Bernareggi 2013).

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.

Jose Maria Paricio, Founder & President of APILAM/e-Lactancia

Your contribution is essential for this service to continue to exist. We need the generosity of people like you who believe in the benefits of breastfeeding.

Thank you for helping to protect and promote breastfeeding.

José María Paricio, founder of e-lactancia.

Other names

Congenital Hypothyroidism is also known as

Congenital Hypothyroidism in other languages or writings:


Congenital Hypothyroidism belongs to this group or family:


  1. Chon DA, Reisman T, Weinreb JE, Hershman JM, Leung AM. Concurrent Milk Ingestion Decreases Absorption of Levothyroxine. Thyroid. 2018 Abstract
  2. Pirola I, Gandossi E, Brancato D, Marini F, Cristiano A, Delbarba A, Agosti B, Castellano M, Cappelli C. TSH evaluation in hypothyroid patients assuming liquid levothyroxine at breakfast or 30 min before breakfast. J Endocrinol Invest. 2018 Abstract
  3. Marina M, Ceda GP, Aloe R, Gnocchi C, Ceresini G. Circulating concentrations of free thyroxine after an oral intake of liquid LT4 taken either during fasting conditions or at breakfast. Acta Biomed. 2017 Abstract
  4. Castilla Peón MF. Hipotiroidismo congénito. [Congenital hypothyroidism]. Bol Med Hosp Infant Mex. 2015 Abstract Full text (link to original source) Full text (in our servers)
  5. Léger J, Olivieri A, Donaldson M, Torresani T, Krude H, van Vliet G, Polak M, Butler G; ESPE-PES-SLEP-JSPE-APEG-APPES-ISPAE.; Congenital Hypothyroidism Consensus Conference Group.. European Society for Paediatric Endocrinology consensus guidelines on screening, diagnosis, and management of congenital hypothyroidism. J Clin Endocrinol Metab. 2014 Abstract Full text (link to original source) Full text (in our servers)
  6. Ianiro G, Mangiola F, Di Rienzo TA, Bibbò S, Franceschi F, Greco AV, Gasbarrini A. Levothyroxine absorption in health and disease, and new therapeutic perspectives. Eur Rev Med Pharmacol Sci. 2014 Abstract
  7. (GPC). Ministerio de Salud Pública. Diagnóstico y tratamiento del hipotiroidismo congénito (HC). Guía de Práctica Clínica (GPC). 1.a Edición. Quito: Programa Nacional de Genética y Dirección Nacional de Normatización; 2014 2014 Full text (link to original source) Full text (in our servers)
  8. Lawrence RM. Circumstances when breastfeeding is contraindicated. Pediatr Clin North Am. 2013 Feb;60(1):295-318. Abstract
  9. Bernareggi A, Grata E, Pinorini MT, Conti A. Oral liquid formulation of levothyroxine is stable in breakfast beverages and may improve thyroid patient compliance. Pharmaceutics. 2013 Abstract
  10. Brown R, LaFranchi S, Rose S. Congenital Hypothyroidism. Fact sheet. The Hormone Health Network 2012 Full text (link to original source) Full text (in our servers)
  11. Brown R, LaFranchi S, Rose S. Hipotiroidismo congénito. Hoja informativa. The Hormone Health Network 2012 Full text (link to original source) Full text (in our servers)
  12. Grob F, Martínez-Aguayo A. Hipotiroidismo congénito: un diagnóstico que no debemos olvidar. [congenital hypothyroidism: a diagnosis not to forget]. rev chil Pediatr 2012; 83 (5): 482-491. 2012 Full text (link to original source) Full text (in our servers)
  13. Bach-Huynh TG, Nayak B, Loh J, Soldin S, Jonklaas J. Timing of levothyroxine administration affects serum thyrotropin concentration. J Clin Endocrinol Metab. 2009 Abstract
  14. Hahn HB Jr, Spiekerman AM, Otto WR, Hossalla DE. Thyroid function tests in neonates fed human milk. Am J Dis Child. 1983 Abstract
  15. Sack J, Frucht H, Amado O, Brish M, Lunenfeld B. Breast milk thyroxine and not cow's milk may mitigate and delay the clinical picture of neonatal hypothyroidism. Acta Paediatr Scand Suppl. 1979 Abstract
  16. Varma SK, Collins M, Row A, Haller WS, Varma K. Thyroxine, tri-iodothyronine, and reverse tri-iodothyronine concentrations in human milk. J Pediatr. 1978 Abstract
  17. Sack J, Amado O, Lunenfeld B. Thyroxine concentration in human milk. J Clin Endocrinol Metab. 1977 Abstract

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