UniSA BackOff! Study: Adelaide PrenaBelt Trial

Stillbirth (SB) is a devastating complication of pregnancy and contributes to over 2 million deaths globally every year. Over 20 million infants are born every year with low birth weight (LBW), which is associated with a twenty times increased risk of death in the first year of life and high rates of short- and long-term illnesses. Sleeping on one's back during pregnancy has recently emerged as a potential risk factor for LBW and SB in the medical literature. In high-income countries, SB rates have mostly remained the same in the past two decades and targeting modifiable risk factors could help reduce the number of SB and LBW in the population.

When a pregnant woman sleeps on her back, her body position compresses underlying blood vessels and reduces blood flow to the developing baby. This body position could cause unpleasant symptoms for the mother and result in LBW or SB of her baby. Lying on her side or with a slight lateral tilt helps relieve this compression. One way to keep people off their back while sleeping is by using positional therapy (PT). It is a simple, safe, inexpensive and effective intervention for preventing people who snore or people who's breathing pauses during sleep from sleeping on their back. Reducing the amount of time pregnant women sleep on their back could help reduce SB and LBW rates. The investigators developed a PT device (PrenaBelt) and tested it in three clinical trials, which demonstrated that it significantly decreases the number of time women spend sleeping on their back. Using feedback from our previous research, the investigators developed five additional devices that will be tested in this study.

The purpose of this study is to evaluate the new PrenaBelt (PB2) prototypes' ability to reduce the amount of time pregnant women sleep on their backs in the third trimester of pregnancy, validate the Ajuvia Sleep Monitor, and collect feedback on the devices.

Demonstrating that the sleeping position of pregnant women can be modified through the use of a simple, inexpensive PT intervention may be one of the keys to achieving significant reductions in LBW and late SB rates in Australia and worldwide.

The ability of the PB2 prototypes to reduce the amount of time pregnant women spend sleeping on their backs at night in the home setting in the third trimester of pregnancy will be evaluated via a consecutive, six-night, in-home, controlled, cross-over sleep study in third trimester pregnant women where the Ajuvia Sleep Monitor is validated against infrared video on the first night.

Six nights: the first night is a control night with infrared video recording where only the Ajuvia is worn in passive mode to collect data on the participant's body position and is followed by five nights with the five different prototypes.

Randomization: The order in which the different devices will be worn on the second night through fourth night, inclusive, will be determined by simple randomization. This will minimize the potential impact of changes to sleep across the nights resulting from familiarization with the equipment as the sleep tests proceed through the five non-control nights, which could bias the results. For logistical reasons, the sixth night is non-randomized and will include the Ajuvia in 'active' mode Cross-over: After the first night, on each of the subsequent four nights, the participants will "cross over" to a different PB2 device (depending on their randomization order) and "cross over" to the Ajuvia in 'active' mode on the sixth night to allow each participant to act as her own control for comparison of treatment effect on outcomes.

In home: conducting this study in the home setting will allow for a more accurate representation of sleep patterns as the participants will be in the comfort of their own bed.

Sleep test: The maternal pelvis position will be recorded while the participants are sleeping using the Ajuvia device. Going to bed- and wake-times, as well as experience with each device will be recorded daily in a sleep diary.

Eligibility Criteria:
Inclusion Criteria:

* ≥18 years old
* low-risk singleton pregnancy
* in the last trimester of pregnancy (at least 28 weeks + 0 days but not more than 36 weeks + 0 days of gestation)
* access to and ability to use iPhone (for downloading and using Ajuvia app)
* residing in the Greater Adelaide Area.

Exclusion Criteria:

* musculoskeletal disorder that prevents sleeping supine or on a certain side (e.g., arthritic shoulder)
* non-English speaking and reading