Last update March 29, 2022
A natural Estrogen that is marketed for oral, injection and topical administration (skin and vaginal). On the chemical form of valerate, it is used in association with a progestin as a combined contraceptive. Estradiol is found naturally in breast milk. (McGarrigle 1983)
Estradiol is excreted into breast milk in clinically insignificant (Nilson 1978) or null amounts (Pinheiro 2016, Perheentupa 2004) and no problems have been observed in infants whose mothers were treated. (Reisman 2018, Pinheiro 2016)
Plasma levels of these infants were undetectable or very low. (Pinheiro 2016)
After administration in the form of transdermal patches milk levels have been undetectable. (Pinheiro 2016, Perheentupa 2004)
Despite these data, an older publication associated the use of transdermal estradiol with a case of jaundice and poor weight gain. (Ball 1999).
Estrogens, alone or associated with progestogens, have been used in the treatment of excess milk production(Johnson 2020) and to suppress lactation (Piya 2004, Balmer 1971), although with very little effectiveness.(Kaern 1967)
There is evidence (albeit inconsistent) that estrogen-containing pills may decrease milk production or the duration of breastfeeding, especially if given during the first few weeks postpartum with a daily dose equal to or greater than 30 micrograms (0,03 mg) diarios. (WHO 2002, AAP 2001, Moretti 2000, WHO 1988, Nilsson 1986, Tankeyoon 1984, Díaz 1983, Peralta 1983, Croxatto 1983, Guiloff 1974, Kaern 1967)
Treatment with high doses of estrogens during adolescence does not affect later ability to breastfeed. (Jordan 2007)
The American Academy of Pediatrics states that this medication is usually compatible with breastfeeding. (AAP 2001)
No short-term or long-term clinical, physical or psychomotor developmental problems have been observed in infants whose mothers were taking combined oral contraceptives (Nilsson 1986), except for a few cases published years ago of transient gynecomastia in infants whose mothers were taking a combined oral contraceptive with ethinyl estradiol. (Madhavapeddi 1985, Nilsson 1978, Marriq 1974, Curtis 1964)
Hormonal contraceptives, both combined and progestogen-only, do not alter the composition of milk, neither in minerals (Mg, Fe, Cu, Ca, P) nor in fats, lactose, proteins or calories. (Urzica 2013, Dórea 2000, 1999 y 1998, Costa 1992)
No study has found negative effects on breast milk production or infant weight gain when combined oral contraceptives (estrogen + progestin) are started after the first 2, or better 6, weeks postpartum. (Tepper 2015, Espey 2012)
During lactation progestin-only drugs are preferred or in combination with estrogen for birth control, but whatever, the ones with the lower doses of estrogen should be used. (CDC 2016, 2013 y 2010, WHO 2015, Berens 2015, CLM 2012)
For the first 6 weeks postpartum, non-hormonal methods are of choise. (Berens 2015, Rowe 2013)
We do not have alternatives for G03CA03.
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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