The Basics
What is Estradiol?
Used to help reduce symptoms of menopause (such as hot flashes, vaginal dryness).
Brand names for Estradiol
Estrace
How Estradiol is classified
Estrogens, Hormones
Estradiol During Pregnancy
Estradiol pregnancy category
Category XNote that the FDA has deprecated the use of pregnancy categories, so for some medications, this information isn’t available. We still think it’s useful to list historical info, however, given what a common proxy this has been in the past.
What we know about taking Estradiol while pregnant
Estrace should not be used during pregnancy.
Taking Estradiol While Breastfeeding
What are recommendations for lactation if you're taking Estradiol?
Limited information on the use of estradiol during breastfeeding indicates that the route of administration and dosage form have influences on the amount transferred into breastmilk. Vaginal administration results in measurable amounts in milk, but transdermal patches do not. Maternal doses of up to 200 mcg daily transdermally do not increase estradiol or estriol in breastfed infants or cause any adverse effects in breastfed infants. Vaginal administration results in unpredictable peak times for estradiol in breastmilk, so timing of the dose with respect to breastfeeding is probably not useful. A case report of inadequate milk production and inadequate infant weight gain was possibly caused by transdermal estradiol initiated on the first day postpartum, but 2 small studies found no such effect when the drug was initiated after lactation was well established.
Maternal / infant drug levels
Limited information on the use of estradiol during breastfeeding indicates that the route of administration and dosage form have influences on the amount transferred into breastmilk. Vaginal administration results in measurable amounts in milk, but transdermal patches do not. Maternal doses of up to 200 mcg daily transdermally do not increase estradiol or estriol in breastfed infants or cause any adverse effects in breastfed infants. Vaginal administration results in unpredictable peak times for estradiol in breastmilk, so timing of the dose with respect to breastfeeding is probably not useful. A case report of inadequate milk production and inadequate infant weight gain was possibly caused by transdermal estradiol initiated on the first day postpartum, but 2 small studies found no such effect when the drug was initiated after lactation was well established.
Possible effects of Estradiol on milk supply
Thirteen women who were 12 weeks postpartum and fully breastfeeding their infants were given a transdermal patch that released 100 mcg of estradiol daily. The average number of breast feeds per day did not change significantly during 3 days of patch application.[6]
Nineteen women who were 6 weeks postpartum, using a barrier contraceptive method and breastfeeding their infants were randomized to transdermal patches that released estradiol 50 mcg daily or placebo patches for 12 weeks. An additional control group received no patches. The number of breast feeds per day decreased in all groups over the course of the study, but there were no important differences among the groups.[7]
A retrospective cohort study compared 371 women who received high-dose estrogen (either 3 mg of diethylstilbestrol or 150 mcg of ethinyl estradiol daily) during adolescence for adult height reduction to 409 women who did not receive estrogen. No difference in breastfeeding duration was found between the two groups, indicating that high-dose estrogen during adolescence has no effect on later breastfeeding.[8]
Possible alternatives to Estradiol
Ethinyl Estradiol.
List of References
Lactation sources: Drugs and Lactation Database (LactMed) [Internet]. Bethesda (MD): National Library of Medicine (US); 2006-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK501922/1. Nilsson S, Nygren KG, Johansson ED. Transfer of estradiol to human milk. Am J Obstet Gynecol. 1978;132:653-7. PMID: 717472
2. Perheentupa A, Ruokonen A, Tapanainen JS. Transdermal estradiol treatment suppresses serum gonadotropins during lactation without transfer into breast milk. Fertil Steril. 2004;82:903-7. PMID: 15482766
3. Pinheiro E, Bogen DL, Hoxha D, Wisner KL. Transdermal estradiol treatment during breastfeeding: maternal and infant serum concentrations. Arch Womens Ment Health. 2016;19:409-13. PMID: 25956588
4. Ball DE, Morrison P. Oestrogen transdermal patches for post partum depression in lactating mothers–a case report. Central Afr J Med. 1999;45:68-70. PMID: 10565065
5. Reisman T, Goldstein Z. Case report: Induced lactation in a transgender woman. Transgend Health. 2018;3:24-6. PMID: 29372185
6. Illingworth PJ, Seaton JEV et al. Low dose transdermal oestradiol suppresses gonadotrophin secretion in breast-feeding women. Hum Reprod. 1995;10:1671-7. PMID: 8582959
7. Perheentupa A, Critchley HOD, Illingworth PJ et al. Enhanced sensitivity to steroid-negative feedback during breast-feeding: low-dose estradiol (transdermal estradiol supplementation) suppresses gonadotropins and ovarian activity assessed by inhibin B. J Clin Endocrinol Metab. 2000;85:4280-6. PMID: 11095468
8. Jordan HL, Bruinsma FJ, Thomson RJ et al. Adolescent exposure to high-dose estrogen and subsequent effects on lactation. Reprod Toxicol. 2007;24:397-402. PMID: 17531440
Disclaimer: This material is provided for educational purposes only and is not intended for medical advice, diagnosis, or treatment. Consult your healthcare provider with any questions.
