You are seeing your next patient in urgent care, a 35-year-old female with a wrist injury who has been waiting for 6-hours. After sending her for an x-ray and offering pain control in the ED, she tells you she is 3-months post-partum and is currently nursing. She asks if there are any pumps available in the ED for her to use, and if the medication you are giving her is safe for her infant. 

In the emergency department, it is quite common to encounter lactating patients; they are either patients themselves, or may be visiting others. In the ED specifically, excessive (unanticipated) wait times, lack of physical space, situational stress, and lack of provider knowledge present unique challenges. 

This blog post will review basics of lactation physiology, chestfeeding complications, medication and diagnostic imaging considerations.


Lactation Physiology


First, it is important to understand the basics of lactation physiology, to better advocate for and support lactating ED patients.

For newborns, it is recommended to feed every 8-12 times/day, with feeding sessions ranging from 5-10 minutes to sometimes up to an hour.  Once lactation is established and maintained, production is regulated by a substance that is called feedback inhibitor of lactation (FIL). The role of FIL is to regulate the amount of milk produced based on how much the baby takes (Figure 1). Removing milk removes the inhibitor, and promotes milk secretion. If the milk is not removed, elevated intra-mammary pressure and accumulation of FIL reduce milk production. 



Therefore, to ensure adequate supply is maintained, it is important to advocate for infant feeding or to offer breast pumps while patients wait to be seen and treated.  Additionally, we must be aware of repercussions when as providers we advise patients to “pump and dump” or to not feed their infant in response to certain treatments or medications provided. This can decrease supply, lead to complications such as mastitis/abscess, and jeopardize a healthy nursing journey between the patient and their infant.


Complications of Lactation


Complications on the “mastitis spectrum” can arise from lactating, which results from ductal inflammation and edema (Figure 2). If ductal narrowing and alveolar congestion are worsened by overstimulation of milk production, inflammatory mastitis can develop. This can then progress into acute bacterial mastitis, a phlegmon, or abscess.


Figure 2. Mastitis spectrum


The Academy of Breastfeeding Medicine revised its guidelines on the mastitis spectrum in 2022 (Table 1 and 2), which includes:


General Recommendations Medical Interventions
  • Support patients in continuation of breastfeeding
  • Feed on demand, don’t aim to empty the breast. Overfeeding perpetuates a cycle of hyperlactation and is a major risk factor for worsening tissue edema and inflammation
  • No evidence for dangle feeding
  • Minimize breast pump usage: pumping does not provide the opportunity for bacterial exchange between the infant’s mouth and mother’s breasts, and therefore it predisposes to dysbiosis
  • No need to pump and dump – bacterial mastitis is not a contraindication to breastfeeding
  • Avoid deep tissue massage of the lactating breast
  • Ice
  • Anti-inflammatory medications/NSAIDS
  • Sunflower or soy lecithin 5-10g daily PO may be taken to reduce inflammation in ducts and emulsify milk
  • Utilize therapeutic ultrasound. Can be performed under supervision of a trained physician or physiotherapist on a daily basis until relief is achieved.
  • Antibiotics for bacterial mastitis
  • Phelgmon: extensive antibiotics and close follow-up
  • Abscess: antibiotics x10-14 days and needle aspiration/drain


Table 1. General management of mastitis


Table 2. Medical management of mastitis


Drugs and diagnostic imaging in lactating patients

Emergency physicians must be comfortable counseling patients regarding medication use and (dis)continuing chestfeeding. The QR code below will guide you to resources you can use as a physician and serve as a patient resource about the safety of drugs in lactating patients.

Figure 3 Lactation resources


Table 3 is a review of commonly used medications in the ED and their safety profile for lactating. However, for any drug, in practice, you can use the LactMed® website.

In general, the safety of drugs in lactating patients is described by the relative infant dose (RID). This is the weight-adjusted percentage of the parental dosage ingested by a fully chestfed infant. An RID of <10% is considered safe, caution is required when the RID is 10-25%, and drugs with an RID of >25% is generally considered not safe.

Table 3. Medications and diagnostic imaging


  • Rosa Ramaekers

    Dr. Rosa Ramaekers is FRCPC Emergency Physician who completed her residency at the University of Ottawa, with a special interest in Pediatrics.

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  • Courtney Price

    Dr. Courtney Price is an FRCPC Emergency Medicine resident at the University of Ottawa, and junior editor for the EMOttawa Blog.

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