Towards BirthAlert--A Clinical Device Intended for Early Preterm Birth Detection

Bioengineering and the cervix: The past, current, and future for addressing preterm birth

The uterine cervix plays two important but opposing roles during pregnancy - as a mechanical barrier that maintains the fetus for nine months and as a compliant structure that dilates to allow for the delivery of a baby. In some pregnancies, however, the cervix softens and dilates prematurely, leading to preterm birth. Bioengineers have addressed and continue to address the lack of reduction in preterm birth rates by developing novel technologies to diagnose, prevent, and understand premature cervical remodeling. This article highlights these existing and emerging technologies and concludes with open areas of research related to the cervix and preterm birth that bioengineers are currently well-positioned to address.

Cultural considerations and beliefs surrounding preterm birth in Kenya and South Africa

BACKGROUND

Preterm birth (PTB) is a global health epidemic, sub-Saharan Africa is severely impacted due to its limited healthcare resources. Pregnancy knowledge, cultural beliefs and practices play a role in the identification of risk and management of PTB. This study explored knowledge, understandings, cultural beliefs and attitudes to pregnancy and PTB, as well as cultural considerations for the introduction of an intravaginal device which could be used to identify PTB risk.

METHODS

Qualitative research was conducted in South Africa and Kenya. In-depth interviews were conducted using semi-structured guides with women with a history of PTB (n = 10), healthcare providers (n = 16) and health systems experts (n = 10); and 26 focus group discussions with pregnant women seeking antenatal care (n = 132) and community male partners/fathers (n = 54). Interviews/discussions were transcribed, translated, and analysed thematically.

RESULTS

Pregnancy knowledge, especially for first time pregnancies was poor, with many reporting late entry to antenatal care. Knowledge about PTB was understood in terms of gestational age, weight or small size of baby, with concerns about long term health and stigma. Various risk factors for PTB were described, including those related to traditions and beliefs of witchcraft/curses. Cultural practices, such as the use of traditional medicines and pica, and religion and its impact on health seeking behaviour were also viewed as risk factors. Although insertion of intravaginal devices was not widely acceptable in traditional communities, especially during pregnancy, it was felt that the use of one to detect risk of PTB would be accepted if proven effective in reducing PTB risk.

CONCLUSIONS

Various culturally-informed beliefs exist which explain understandings of and attitudes toward pregnancy, pregnancy risk, and PTB. An inclusive exploratory process is critical to facilitate an understanding of the beliefs and traditions which could impact the introduction and design of a product to detect the risk of PTB.

Toward an intravaginal device to detect risk of preterm labor: a user-centered design approach in Sub-Saharan Africa

Background

Prematurity and its complications are the leading cause of death and disability in children under five in Africa and North America, affecting as many as one in ten pregnancies. Screening tests to predict preterm birth (PTB) are insensitive, costly, and often unavailable in low resource settings. In parallel with early-stage U.S.-based testing of a novel self-placed intravaginal device to predict PTB risk, we elicited key stakeholder input from two sub-Saharan African countries to ensure local contextual factors inform future development of the device and its acceptability.

Methods

A qualitative study was conducted in Kiambu County, Kenya and KwaZulu-Natal Province, South Africa. We conducted 26 focus group discussions with pregnant women (n = 132) and males from the community (n = 54); in-depth interviews with women who had a history of PTB (n = 10), healthcare providers (n = 16), and health system experts (n = 10). Interviews were transcribed and thematic analysis was performed using an iterative coding technique. In addition, we facilitated user-centered design sessions to generate prototype preferences.

Results

Women with a personal history of PTB were almost unanimous in support of the proposed device, whereas those with no experience of PTB expressed the greatest degree of reservation. Healthcare providers anticipated that women with a history of PTB would accept the device. However, various potential challenges were identified, including potential discomfort with device insertion, hygiene, and sexual activity, as well as need for provider training, and attention to country-specific regulatory processes. Both community participants and providers expressed a preference for a provider inserted device. Design recommendations included preference for a small, soft, pliable device, with a shape that could facilitate easy removal.

Conclusions

Use of an intravaginal device to detect risk of PTB was generally acceptable, however stakeholders expressed a notable preference for insertion by providers. This reflects the significance of end-user consultation in device design and use. Recommended device modifications as well as educational messaging and provider technical assistance may facilitate utilization.

Prematurity and its complications are the leading cause of death and disability in children under 5 years of age. Up to ten percent of pregnancies in North America and Africa are affected. Screening tests to predict preterm birth (PTB) are insensitive, costly, and often unavailable in low resource settings. A U.S.-based study has developed an intravaginal device to detect preterm labor. In order to assess acceptability and guide development for a low-resource setting, a qualitative study was conducted in Kenya and South Africa. We conducted focus group discussions and interviews with pregnant women, male community members, health care providers and health systems experts. Participants with a personal history of PTB were almost unanimous in support of the proposed device; women with no experience of PTB expressed the greatest degree of reservation. Various potential challenges were identified: discomfort, hygiene, and sexual activity, the need for provider training and attention to country-specific regulatory processes. Design recommendations included preference for a small, soft, pliable device, with a shape that could facilitate easy removal. Stakeholders expressed a strong preference for insertion by providers. These findings reflect the significance of end-user consultation in device design and use.

Biomechanics of the human uterus

The appropriate biomechanical function of the uterus is required for the execution of human reproduction. These functions range from aiding the transport of the embryo to the implantation site, to remodeling its tissue walls to host the placenta, to protecting the fetus during gestation, to contracting forcefully for a safe parturition and postpartum, to remodeling back to its nonpregnant condition to renew the cycle of menstruation. To serve these remarkably diverse functions, the uterus is optimally geared with evolving and contractile muscle and tissue layers that are cued by chemical, hormonal, electrical, and mechanical signals. The relationship between these highly active biological signaling mechanisms and uterine biomechanical function is not completely understood for normal reproductive processes and pathological conditions such as adenomyosis, endometriosis, infertility and preterm labor. Animal studies have illuminated the rich structural function of the uterus, particularly in pregnancy. In humans, medical imaging techniques in ultrasound and magnetic resonance have been combined with computational engineering techniques to characterize the uterus in vivo, and advanced experimental techniques have explored uterine function using ex vivo tissue samples. The collective evidence presented in this review gives an overall perspective on uterine biomechanics related to both its nonpregnant and pregnant function, highlighting open research topics in the field. Additionally, uterine disease and infertility are discussed in the context of tissue injury and repair processes and the role of computational modeling in uncovering etiologies of disease. WIREs Syst Biol Med 2017, 9:e1388. doi: 10.1002/wsbm.1388 For further resources related to this article, please visit the WIREs website.

Rapid and low-cost prototyping of medical devices using 3D printed molds for liquid injection molding

Biologically inert elastomers such as silicone are favorable materials for medical device fabrication, but forming and curing these elastomers using traditional liquid injection molding processes can be an expensive process due to tooling and equipment costs. As a result, it has traditionally been impractical to use liquid injection molding for low-cost, rapid prototyping applications. We have devised a method for rapid and low-cost production of liquid elastomer injection molded devices that utilizes fused deposition modeling 3D printers for mold design and a modified desiccator as an injection system. Low costs and rapid turnaround time in this technique lower the barrier to iteratively designing and prototyping complex elastomer devices. Furthermore, CAD models developed in this process can be later adapted for metal mold tooling design, enabling an easy transition to a traditional injection molding process. We have used this technique to manufacture intravaginal probes involving complex geometries, as well as overmolding over metal parts, using tools commonly available within an academic research laboratory. However, this technique can be easily adapted to create liquid injection molded devices for many other applications.