Oestrogen creams and pessaries seem to be prescribed with increasing frequency to breastfeeding women to help with healing of sutures, prolapses or for ongoing vaginal dryness. There is little research evidence to guide a discussion of compatibility with breastfeeding.
Breastfeeding does seem to have an effect on natural vaginal lubrication for some and basics products such as KY Jelly®, Replens®, Sylk® and other products may help.
But for others oestrogen creams may be prescribed by the GP or an obs and gynae consultant.
It is known that vaginal absorption of oestrogen results in measurable amounts in milk (LactMed, Hale).
In Nielson’s study 6 lactating mothers were given vaginal suppositories (pessaries) containing 50 or 100 mcg of oestradiol. Levels of oestradiol were measurable in milk whilst before application of the pessaries the levels was below that of detection. According to Nielson a ratio of transfer of estradiol from plasma to milk during physiologic conditions is calculated to be less than 100:10. Peak levels were found in milk between 3 and 11 hours after application but was inconsistent and irrelevant with ongoing use. Outcome data is not given in the data that I have been able to access.
Nilsson S, Nygren KG, Johansson ED. Transfer of estradiol to human milk. Am J Obstet Gynecol. 1978;132:653-7.
Hale says vaginal absorption is greater than oral and quotes Chollet who studied atrophic vaginitis in post menopausal women. It is unclear what relevance this has to brestfeeding
Chollett J. A., G. Carter, et al. (2009). “Efficacy and safety of vaginal estriol and progesterone in postmenopausal women with atrophic vaginitis.” Menopause 16(5): 978-983.
Levels of oestradiol in the 2 most commonly used products are:
Ovestin – One applicator-dose contains 0.5 mg estriol.
Vagifem contains 10 mcg estradiol per vaginal tablet
neither product is licensed to be used in lactation.
Anecdotally some mothers have reported that their supply has dropped but by no means everyone.