Ghana PrenaBelt Trial: A Positional Therapy Device to Reduce Still-Birth

Introduction:

According to the World Health Organization (WHO), stillbirth (SB) is defined as fetal death at gestation ≥28 weeks or weight ≥1000g. In addition to the loss of life for the stillborn baby, parents whose baby is stillborn must cope with the psychological grief of losing their baby, which results in markedly increased mortality in bereaved parents when compared with non-bereaved parents.

Low birth-weight (LBW) is defined as a weight less than 2500g at birth. LBW is a significant contributor to SB, and infants with LBW are 20 times more likely to die in the first year than heavier babies. Although LBW babies constitute only about 15% of live births, they account for 60-80% of neonatal deaths. Neonatal deaths (death within the first year of life) account for 40% of all deaths under the age of five years. LBW also accounts for significant morbidity such as cognitive impairment, and chronic diseases later in life. LBW arises through short gestation (preterm birth) or in-utero growth restriction, or both.

Women in Ghana suffer from one of the highest perinatal mortality rates in the world. Every day in Ghana, 47 babies are stillborn and 232 babies are born with LBW - many of whom will die in infancy or suffer lifelong consequences. As such, Ghana urgently requires inexpensive interventions to reduce perinatal morbidity and mortality - assisting pregnant Ghanaian women to avoid sleeping on their back might be one such intervention.

Background - Maternal Position:

In obstetrics, it is well-known that when a pregnant woman assumes the supine position (laying on her back) during the day, maternal cardiovascular parameters and/or fetal oxygenation are altered, occasionally causing significant fetal heart rate changes, particularly during labor. However, until recently, there has been little evidence on the effect of supine position during sleep in pregnancy. Recently, three studies have suggested that maternal sleep position may be a risk factor for SB and LBW. This is significant given that the majority of third trimester pregnant women spend up to 25% of their sleep time supine. In the Auckland Stillbirth Study, the population attributable risk (PAR) for non-left sleep position to SB was found to be 37%, which is greater than the PARs of the three most important modifiable risk factors for SB (obesity, advanced maternal age, and smoking) combined. In an African population, investigators on this protocol found that supine sleep during pregnancy was an independent predictor of LBW (OR, 5.0; 95% confidence interval (CI), 1.2-20.2; P=0.025) and SB (OR, 8.0; 95% CI, 1.5-43.2; P=0.016), when controlling for covariates maternal age, gestational age, parity, and the presence of pre-eclampsia. Notably, LBW was found to mediate the relationship between supine sleep and SB. Currently, there is much interest and follow up research occurring worldwide, with a growing body of evidence regarding the detrimental effects of supine sleep position on pregnancy outcomes.

One proposed model is that the maternal supine position during sleep is a stressor that plays a causative role in LBW and SB via compression of the abdominal aorta and inferior vena cava ('aortocaval compression'), resulting in negative sequelae. The investigators hypothesize that by mitigating this stressor, they may protect the fetus from LBW or SB.

Background - Maternal Device:

Given the emerging data suggesting that supine sleep may play a role in LBW and SB and the high perinatal mortality rate in Ghana, a simple intervention may allow the investigators to improve fetal outcomes.

Some pregnant women sleep with many pillows supporting their body, including a pillow behind their back to avoid the supine position. Asking women to sleep on their left increases the percentage of left sided sleep to approximately 60% of the night; however, this may come at a cost of a slightly reduced sleep duration, perhaps due to women feeling they need to make a conscious effort to maintain a certain sleep position.

Hence, a simple, low-cost, and easily-implemented device has been developed for use by pregnant women to mitigate this risk factor. The investigators anticipate that using this device will remove the need for the woman to make a conscious effort to avoid the supine sleeping position. The device name is 'PrenaBelt'. The PrenaBelt is currently at the prototype stage of development, and as such, this proposal is a proof-of-concept/feasibility project.

The PrenaBelt is a belt-like, positional therapy device designed specifically for pregnant women. While the PrenaBelt does not prevent the user from lying on her back during sleep, it is expected to significantly decrease the amount of time she spends in this position via the mechanism of positional therapy. Positional therapy is a simple, non-invasive, inexpensive, long-established, safe, and effective intervention for preventing people with positional-dependent snoring or mild to moderate obstructive sleep apnea from sleeping on their back - a position that exacerbates their condition.

The PrenaBelt is worn at the level of the waist. By virtue of its design and position on the user's body, the PrenaBelt affects subtle pressure points on the back of the user when she lies on her back. These subtle pressure points activate her body's natural mechanism to spontaneously reposition itself to relieve discomfort, thereby reducing the amount of time she remains on her back during sleep. The PrenaBelt is also designed for adjustability and comfort.

The investigators have designed an electronic Body Position Sensor (BPS) that can be securely integrated into a pocket on the PrenaBelt. The BPS will record body position of the user (left, right, prone, supine). The BPS is for research purposes only.

Study Design:

The feasibility (technical, operational, cultural), efficacy, acceptability, and compliance of the PrenaBelt intervention in the target population during the third trimester of pregnancy in an antenatal care clinic and home settings and the effect of PrenaBelt treatment on birth weight will be evaluated via a sham-controlled, double-blind, randomized controlled trial. Preliminary data will be collected for the design of a future, large-scale, parallel-group, randomized controlled trial to determine the efficacy of the PrenaBelt intervention in improving pregnancy outcomes in a resource-limited setting.

A small cohort of participants from the treatment and control groups will be randomly selected to use BPS's throughout the third trimester of pregnancy. Each BPS participant in the treatment group will be matched to a BPS participant in the control group using BMI (normal, overweight, obese) and age (within 5 years; 2.5 years each side) as matching variables and BPS data will be compared. These data will serve as preliminary objective evidence of PrenaBelt usage and effect on maternal sleeping position during the third trimester of pregnancy in the target population and setting.

Potential Harms:

This study is minimal risk. Participants in this study are at no greater risk of harms when completing the activities of this study than those risks they encounter in their everyday life.

The PrenaBelt, sham-PrenaBelt, and Body Position Sensor devices are non-invasive medical devices of Health Canada Class I designation. Pregnant women typically sleep with many pillows supporting their body, including a pillow behind their back to avoid the supine position. The PrenaBelt is a positional therapy device that may assist pregnant women to avoid supine sleep. Positional therapy devices have been shown to be safe and approved for use by humans by the US Food and Drug Administration. In addition, maternal body pillows, regular pillows, and pelvic belts (lumbar support) have been used by pregnant women during sleep without reports of serious adverse effects for the mother or neonate [Victoria Pennick and Sarah D Liddle, "Interventions for preventing and treating pelvic and back pain in pregnancy (Review)," The Cochrane Collaboration, London, Review 2013].

Participants in both the intervention and control groups may experience discomfort while learning to sleep with the PrenaBelt/sham-PrenaBelt, which theoretically may lead to delayed onset of sleep, arousals from sleep, and loss of sleep. Participants will be instructed how to, and told that they can, remove the PrenaBelt/sham-PrenaBelt and discontinue use at any time without penalty if they become too uncomfortable.