Ma Belly: A Low-Cost, Smart Maternity Belt

My collaborators Kat Hartman (Detroit), Sasha Kinney (Nairobi), and I developed this proposal for the UNICEF Wearables for Good Challenge. Additional insights by Josh Ogure and Christine Fernandez, also in Nairobi.

Ma Belly is a biodynamic maternity belt that can be optionally outfitted with a “smart” sensors component. Basic maternity belts have been in wide use for many years; they are textile-based support structures, worn in the space between the stomach and the pubis, meant to help ease pregnancy-related back, hip, and pelvis discomfort for a pregnant mother. These belts also help prevent stretch marks. They can be made from inexpensive materials, making them relatively affordable even in resource-constrained communities.

Ma Belly builds on the basic maternity belt by integrating biodynamic materials that sense the wearer’s body and the surrounding environment, for example: hydrochromic pigment that reacts to water, thermochromic pigment that reacts to heat, photochromic pigment that reacts to sunlight, and mechanichromic pigment that reacts to pressure. Since these pigments do not require electricity, Ma Belly can be used by mothers who have limited access to electricity. The pigments would be applied as a traditional batik-style print, thus making Ma Belly a rugged, durable, attractive belt that many women, both urban and rural, can wear comfortably. A guide will be developed to help expectant mothers and their health care providers understand how the belt can be used to gauge stretch, temperature, humidity, pressure, and light, and how these factors can be relevant indicators for mild conditions, like polyhydramnios, and for serious conditions including hypertension, dilation, and obstructed labor.

Ma Belly can be optionally outfitted with higher-fidelity, passive, soft sensors that use changing resistance values to measure stretch, pressure, and movement. Via a battery-powered microcontroller/wireless module, these sensors can gauge data including pelvic width, fundal length, fetal station, and fetal movement over time. If she chooses, the wearer can SMS the information from Ma Belly to her healthcare provider.

Printed illustrated health communication materials will be developed as an accompanying resource for each belt. These materials will use accessible visuals and language to provide context for its usage, as well as basic usage information and how-to. As a health pregnancy benefits from a holistic approach, mothers-to-be may benefit from illustrated information that includes basic sex education, family planning, stages of pregnancy, nutritional information, benefits of prenatal care & professionally attended births, and methods for identifying pregnancy complications. Additionally, the printed guide will offer insight into how to read the belt and act on the knowledge gleaned.

“Every day, 1000 women die from preventable causes related to pregnancy and childbirth, with 99% of the deaths occurring in developing countries” (Wearables for Good Handbook). Ma Belly’s target user is the expectant mother in the developing country, particularly in Kenya, where our team is partially based, and the country places “51st on the list of the 75 countries where more than 95 percent of all maternal and child deaths occur” (Huffington Post, see URL below).

Ma Belly will help its wearers gain more physical comfort and more information about their pregnancies, but beyond that, Ma Belly will facilitate the space between informal and formal, untrained and trained: the data from Ma Belly can help a mother, who may only have regular access an untrained, informal health care provider, decide to seek professional care. As is the case with most “quantified self” wearables like FitBit and Apple Watch, Ma Belly can also be an inexpensive, efficient mechanism for wearers and carers to view and analyze regularly collected data about the expectant mother. This could be a game changer in helping to prevent common prenatal conditions, particularly since “inadequate or nonexistent care and dearth of resources during pregnancy and delivery is largely responsible for the annual deaths of an estimated 289,000 mothers and 2.8 million newborns in the first month of life.”

As a systems-oriented approach, Ma Belly addresses several major focus areas discussed in UNICEF’s Wearables For Good Handbook: behavior change around prenatal monitoring, nutrition and care; data collection/access to track the health of the mother and fetus and securely transmit information without expensive human or technological resources; and early diagnosis of abnormal prenatal conditions.

Our team has a background in design, technology, data visualization, health communication, creative activism, media development, and citizen journalism; we have experience in both economically developed and developing settings; and we have much experience with user-centered co-design strategies made formal by organizations like ARM, IDEO, MIT Center for Civic Media, Ashoka, and the like. However, our intention is to take this further by collaborating with on-the-ground organizations Carolina for Kibera and/or Jacaranda Health (see more information below) to employ UNICEF’s Innovation design principles in the development and iteration of Ma Belly prototypes. Through this collaboration, we strive to directly employ a data-driven design that is also participatory and human centered, showing an understanding of all relevant users, ecosystems, sustainability, scale, and open innovation practices.

Our greatest technical hurdle is developing a wearable that is “plug and play;” that is, a belt that can be worn immediately, without calibration, and provides consistent, accurate results throughout the entire pregnancy. Once a plug and play belt is developed, it will be important to ensure that wireless modules comply with maternal health practices, and that the entire product can be feasible scaled to mothers in most need.

Adoption of the technology is also a potential hurdle. The intended audience may not initially see the utility or relevance of this new technology. It is essential that a human-centered, co-design process be implemented with the target users in order to ensure that both the belt and the accompanying illustrated communication materials are appealing, comfortable, and relevant. In addition, this participatory process will be focused on building community trust and interest, and further connecting the health system to informal birth attendants who constitute a major service provider, and mothers-to-be. A human-centered approach will allow the technology to meet the user where they are, and working partnerships with community maternal health service providers will allow for the trust-building and collaboration needed to refine the technology and implement it at scale.


– INNER LAYER: Stiff compression textile to support the mother’s back, pelvis, hips, and abdomen. Will also prevent stretch marks.

– MIDDLE LAYER: Sensor grid of low-cost, analog soft sensors (stretch and pressure).

– OUTER LAYER: Batik textile developed with biodynamic, color-changing materials (ie thermochromic, photochromic, hydrochromic, mechanichromic pigments) to immediately indicate temperature, sun, movement, and humidity changes for the wearer, all without the use of electricity.

OPTIONAL COMPONENTS (depending on resource availability)
– Microcontroller and data storage module to process and store sensor signals
– Digital sensors embedded the middle layer (temperature, humidity, infrared)
– GSM (2G) module to send data via SMS

In terms of software, the technology is platform agnostic. A prototyping platform such as Arduino may be used to develop early prototypes, but later prototypes could be built with custom circuit boards that employ low-cost chips like the ATTiny (ARM architecture).