Most breastfeeding mothers take medication, but many are making decisions without good information

When a woman who is breastfeeding develops an infection or a flare of a chronic condition, they face a decision that sounds simple but rarely is: should they take the medication to treat their condition?

As a pharmacist and researcher, I field this question frequently, and the people asking it are usually doing so with far less information than what is available. A study my colleagues and I recently published in the International Breastfeeding Journal aimed to understand more about how parents and health-care providers navigate this question.

What we found

We surveyed 165 breastfeeding parents and 47 health-care providers across Canada about how they make decisions on medication use during lactation. More than half of the parents told us they found these decisions difficult. Close to half said they worried about what could go wrong.

What is concerning is that among parents who had to make a medication decision, more than half deliberately chose not to start a medication while breastfeeding and almost a quarter stopped breastfeeding in order to take one. These are meaningful trade-offs — between a parent’s own health and how they feed their child. Our findings suggest many people are making them without enough support.

When we asked parents and providers what made these decisions hardest, both groups ranked a lack of information about the options, benefits and risks of medications as the number one barrier. For birth parents, the next concern was not knowing which resources to trust. For providers, it was parents’ fear and anxiety, followed by conflicting information from other clinicians.

These findings suggest that clinicians and parents alike share that there often isn’t enough evidence to make an informed decision.

This is a common situation

It’s easy to assume that most breastfeeding women are “young and healthy” and that taking a medication during this time would be unusual. But it isn’t.

In a population-based study using Manitoba prescription dispensing records, my colleagues and I found that approximately 60 per cent of individuals took at least one prescription medication postpartum. Data from the Canadian CHILD Cohort Study, which followed more than 3,500 mother-infant pairs, found that the use of non-prescription products (including multivitamins and natural products) was higher among breastfeeding than non-breastfeeding women (68 per cent versus 49 per cent) in the first three months postpartum.

The most common prescription medication used among breastfeeding women was domperidone taken off-label for increasing milk supply. Even this drug, which is meant to support breastfeeding, does not have an approved indication for this purpose.

Certain prescription medications were more than twice as common among non-breastfeeding women in the first three months postpartum compared to breastfeeding women, such as psychiatric medications (11.2 per cent versus 4.3 per cent). Whether the use of these prescription medications influenced their decision to bottle-feed is not known.

Why the evidence is limited

The main reason evidence is limited is historical. Lactating women have long been excluded from clinical trials and drug development, often on the assumption that leaving them out was the cautious choice. The unintended consequence is that many of them require these medications in the real world and take them with little lactation-specific safety data.

That leaves clinicians extrapolating from animal studies, pharmacokinetic modelling and case reports. Psychiatric medication, pain medication and immunosuppressants were the medications that physicians in our study most often said they weren’t confident counselling on.

Our findings point to a few practical directions.

• Generate lactation evidence earlier: Safety and efficacy data relevant to lactation should be expected as part of drug development rather than gathered piecemeal afterward. The World Health Organization recently identified the importance of including pregnant and breastfeeding women in clinical trials as a matter of health equity, and Canadian regulators have a role to play here.

• Build shared decision-making tools: Encouragingly, most health-care providers in our survey said they share medication decisions with parents rather than deciding for them. But without a structured approach, that process is inconsistent. A decision aid for commonly used medications could help organize the available evidence, draw out what matters to each parent, and work through the risks and benefits together.

• Improve national pharmacovigilance: Adverse effects after medication exposure through breast milk are currently captured inconsistently through general spontaneous reporting systems. Lactation data is buried within these systems and reporting of this data is not cleanly available to the public. A system that intentionally captures breastfeeding-specific information (for example, exclusive versus mixed, maternal versus infant age/history) can greatly improve our monitoring of medication safety during breastfeeding.

When parents stop a medication they need or interrupt breastfeeding earlier than intended, the impact affects both mother and child. With better evidence, clearer decision support and more deliberate data collection, we can give breastfeeding parents and their clinicians a stronger foundation to make an informed choice rather than basing it on uncertainty.