Wearable smart lactation pad detects chemicals and nutrients in breast milk

Biomedical engineers at USC have developed a smart lactation pad that can quantify a wide range of chemicals in breast milk in real time.

Breast milk plays a vital role in infant nutrition and immune development, making lactation health a critical aspect of maternal and child well-being. Lactating individuals face unique health challenges, including nutritional deficiencies, the risk of developing mastitis and the potential transfer of medications and other substances through their milk.

“There are engineering solutions that can transform lactation health. Advances in nanotechnology, microfluidics and flexible electronics have pushed the point-of-care and wearable sensors a long way, but these sensors have not been engineered to address women’s health and lactation needs,” said senior author Maral Mousavi, the WiSE Gabilan Assistant Professor of Biomedical Engineering, Psychiatry, Behavioral Sciences, Chemistry, Pharmacology, and Pharmaceutical Sciences at the USC Viterbi School of Engineering.

“I learned about gaps in lactation health through Melissa Banks, a graduate student who had her first baby while starting PhD studies in my group,” Mousavi added. “We had to act and develop better tools for measurement in breast milk.”

The team faced a tough question: How do you make it easy for a tired, overwhelmed new mom to provide breast milk samples regularly?

That’s when Banks, a doctoral candidate in the Alfred E. Mann Department of Biomedical Engineering, had a lightbulb moment — why not use lactation pads? These everyday essentials, worn inside a bra to absorb leaking milk, are something many breastfeeding parents already use. They’re soft, discreet and perfectly positioned to collect milk without adding any extra hassle. Used lactation pads are typically tossed out at the end of the day, along with the milk they’ve absorbed — so why not turn them into a source of valuable health data instead?

The researchers took the idea one step further by transforming a simple lactation pad into a smart health device. They built in tiny microfluidic channels — think of them as miniature plumbing systems — that guide the milk to a sensing area. There, low-cost electrochemical sensors get to work, detecting and measuring important health markers in the milk. It’s a fusion of everyday comfort and cutting-edge science, designed to give new parents insights into their health and their baby’s, without adding anything to their already full plates.

“We’re exploring a range of biomarkers and health questions through this platform,” Mousavi said. “We’re especially excited that two of our recent studies were just published in Advanced Functional Materials and Device, where we showcase smart lactation pads capable of measuring glucose and acetaminophen levels in breast milk.”

This work is pioneering the first wearable, rapid sensor for at-home measurement of chemicals in breast milk, addressing an important technology gap for improving the health of the mother and the baby.

In the case of the acetaminophen sensor, the device could help protect babies from overexposure to the common painkiller.

Acetaminophen, commonly used for postpartum pain management, is also frequently given to babies to treat fever, leading to potential double-dosing through both direct administration and indirectly through breastfeeding.

Despite being a medicine cabinet staple, the drug is the leading cause of acute liver failure in children and the most frequent reason for liver transplants in the United States.

For nursing babies with immature liver metabolism, the presence of acetaminophen in breast milk poses additional risks. The currently available methods for measuring acetaminophen levels in milk are costly, complex and unavailable for routine use in the home.

“After having my daughter via C-section, I was on large doses of Tylenol for pain control in the days after surgery and wished there was a way to monitor the amount transferring to my baby, as it can be hard on their tiny livers,” Banks said.

“This was the impetus for developing our smart lactation pads, and we hope that they will help mothers in the same position make more informed choices regarding breastfeeding, while providing peace of mind,” Banks added. “Although I couldn’t purchase the smart lactation pads commercially, our lab had a working device by the time I had my second daughter.”

The sensor, built right into the absorbent lactation pad, collects small amounts of breast milk naturally released during the let-down reflex throughout the day. It then sends real-time readings to the user’s smartphone via a compact, portable detector that works similarly to a glucometer, using electrical pulses to measure levels of acetaminophen. With this information at their fingertips, users can make informed decisions — such as choosing to pump and discard milk containing medication — ensuring safer feeding for their baby.

Researchers tested the accuracy of the sensor using human milk samples with various levels of acetaminophen. They also verified that the sensor worked throughout the changing composition of breast milk, from colostrum to mature milk.

USC has filed a provisional patent based on this device. Researchers have also developed smart lactation pads that measure glucose in breast milk, which is important for the development of babies’ brains and an important analysis for moms with gestational diabetes.

“We can easily check the nutritional facts of the food we eat by reading food labels, but the same can’t be said for breast milk — the primary source of nutrition for infants during their first few months,” Mousavi said.

Currently, there are limited services where parents can order kits costing anywhere from $100 to $350, fill the sample tube with large amounts of milk and then ship it off to a lab for analysis, with results arriving weeks later. This approach is not only expensive but also infrequent, failing to meet the pressing need for real-time data. For mothers with gestational diabetes and other metabolic disorders, frequent measurement of biomarkers, like glucose in milk, is crucial. Until now, the only affordable tool available to mothers was low-cost alcohol test strips.

“I’m excited that our work is bringing us one step closer to the reality of accessible, affordable tools designed to meet the unique health needs of women. We are at the start of this road and will continue to expand the sensing capabilities of our smart lactation pads,” Mousavi said.

In addition to Mousavi and Banks, key contributors to the work include Mona Mohamed, Sina Khazaee Nejad, Haozheng Ma, Abdulrahman Al-Shami, Ali Soleimani, Farbod Amirghasemi and Victor Ong — all members of the Alfred E. Mann Department of Biomedical Engineering at USC Viterbi.

The authors credited Cu Ho, Nhat Nguyen and "the entire team at Mother’s Milk for their invaluable collaboration and support in securing milk samples for the research.”

The research was supported with funding from the 3M Non-Tenured Faculty Award, USC Women in Science and Engineering (WiSE) and the President’s Sustainability Research Award from USC.

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