You and your breastfeeding baby are a symphony of interacting biological systems

Since the end of the World War II, there's been a tendency to think that lactating breasts function like a machine. Some breastfeeding support professionals worry that something is wrong if things don't appear to be predictable, or 'regulated', in your breastfeeding relationship with your baby.

This mistrust of flexibility and variability belongs to an old-fashioned scientific paradigm known as reductionism, which applies linear cause-and-effect explanatory models. Dairy cows better fit this kind of controlled and regimented approach to milk production. Cows have large cisterns in their udders to store milk, for a start, unlike humans.

Now, 21st century science tells us that biological systems operate through complex interactions between elements of the system, and are stabilised by multiple interacting feedback loops. Possums Breastfeeding & Lactation applies a biological systems or complexity science approach to making sense of your lactating breasts and breastfeeding your baby. I draw on complexity science as I help you sort out any problems which arise.

How does complexity science helps us understand breastfeeding problems?

Complex systems are 'nested inside' multiple other complex systems and contain multiple other complex systems within them. Complex systems constantly interact with multiple other complex systems within an organism or social context.

In 2013, I published a research paper showing why a baby who cries and fusses a lot is best conceptualised as part of the complex adaptive system of the mother and baby, or parents and baby, and why if we are to help, we need to equally consider the five domains of parent mental health and wellbeing, infant health (particularly the gut), infant sensory motor development, sleep, and feeds. Instead, unhelpful diagnoses and simplistic treatments are still often give to you or your baby if baby is unsettled.

Complex variations are normal and necessary for the health of a biological system. This dynamism, this constant state of change, gives complex systems their great resilience and also their marvellous capacity to adapt when the context or environment alters. Complex systems are unpredictable. Unexpected things emerge, there is simultaneous self-organisation and also disorder, and the history or experiences of the complex system shapes what is emerging right now. These are all true of breastfeeding and your lactating breasts.

Trying to fit a complex system like you and your breastfeeding baby into the 20th century Industrial Age paradigm of (pre-quantum physics) science, with its emphasis on machines and regulation, can cause all sorts of problems!

Why simplistic treatments can mess things up and do more harm to breastfeeding than good

Helping a complex system like a breastfeeding mother-baby pair stabilise into enjoyable painfree breastfeeding which ensures baby's healthy weight gain usually requires a woman to experiment with multiple interacting strategies, to see what works in her own unique situation.

You can see that this biological systems or complex adaptive systems approach, in Possums Breastfeeding & Lactation, is very different to the old simplistic (or linear way) of thinking about breastfeeding problems, where you look for one main reason (e.g. letdown impairment, or tongue-tie, or nipple thrush, or temperomandibular joint and floor of mouth fascial tightness) and then devise a pharmaceutical or surgical or exercise solution to fix it.

Often, because reductionism is still dominant in the times we live in, people may feel they are being very scientific when they offer these kinds of one-factor or simplistic solutions. But actually, this way of thinking doesn't keep pace with what the latest science is telling us, which is all about complexity.

The problem is that linear or simplistic interventions into complex systems risk unintended outcomes. All interventions have side-effects, which may alter the function of the whole system, and which may not be easily identified by practitioners. This is because many of us as health professionals have not yet been educated in the latest advances of biological systems science, let alone the way it might translate into health system and clinical strategies for breastfeeding support.

Recommended resources

• You can find out about how a mother (or loving carer) and her baby form a single biological system here.

• You can find out more about resilience, the butterfly effect, and being a biological system as you breastfeed your baby here.

• You can find out why the breastfeeding mother-baby pair are a complex adaptive system or CAS (not a dyad) here

• You can find out about complex adaptive systems and complexity science here.

Selected references

Alawadi AQH. Exclusive breastfeeding as a complex adaptive system: a qualitative study. Scientific Journal of Medical Research. 2020;4(15):70-86.

Braithwaite J, Churruca K, Long JC, Louise EA, Herkes J. When complexity science meets implementation science: a theoretical and empirical analysis of systems change. BMC Medicine. 2018;16:63.

Christian P, Smith ER, Lee SE. The need to study human milk as a biological system. American Journal of Clinical Nutrition. 2021;113:1063-1072.

Douglas PS, Hill PS, Brodribb W. The unsettled baby: how complexity science helps. Arch Dis Child. 2011;96:793-797.

Guillen-Morales DdJ, Cruz-Cortes I, Sosa-Velazco TA, Aquino-Dominguez AS. The mother-infant symbiosis: a novel perspective on the newborn's role in protecting maternal breast health. Hygiene. 2025;5(46):https://doi.org/10.3390/hygiene5040046.

Sturmberg J, Topolski S. For every complex problem, there is an answer that is clear, simple and wrong. Journal of Evaluation in Clinical Practice. 2014;6:1017-1025.