After applying Premarin cream, it is important to consider if the treatment will be taken regularly or if it was just a one-time dose. Using estrogen during breastfeeding can potentially decrease milk production and quality. If it was a one-time dose, the risk of significant amounts of estrogen transferring to breast milk is very low. Estrogen is generally considered safe and can even be used for contraception as soon as 6 weeks after giving birth. It is not necessary to stop breastfeeding after a single application. However, if Premarin will be used regularly, it is advisable to consult with a doctor to discuss the pros and cons of the treatment. There may be other treatment options available that could be more suitable for your symptoms.