Timing of maternal and neonatal mortality and morbidity in healthy women and newborns during the postnatal period: a systematic review protocol

OBJECTIVE

To determine the timing of overall and cause-specific maternal and neonatal mortality and severe morbidity in healthy women and newborns during the postnatal period.

INTRODUCTION

Despite significant focus on improving maternal and neonatal outcomes, many women and newborns continue to die or suffer negative health outcomes within the postnatal period. While the maternal and neonatal mortality and morbidity rates and causes are regularly updated, less is known on when they occur during the postnatal period.

INCLUSION CRITERIA

This review will consider studies that include healthy women and newborns after birth to six weeks' and four weeks' postnatally, respectively, and includes data regarding time to death or complications. Studies that report solely on high risk women (eg, antenatal complications) or preterm or high-risk newborns will not be included in this review.

METHODS

The search strategy will aim to locate both published and unpublished studies. After the initial search and removal of duplicates, titles and abstracts of all retrieved studies will be screened and the full text of selected reports will be assessed against the eligibility criteria. The reference list of all studies selected for critical appraisal will be screened for additional relevant studies/reports. Screening, critical appraisal, and data extraction will be completed by two independent reviewers. Findings from the studies/reports will be pooled in statistical meta-analysis or presented in narrative form including tables and figures.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO CRD42020187341.

Congenital anomalies in children with postneonatally acquired cerebral palsy: an international data linkage study

AIM

To describe the major congenital anomalies present in children with postneonatally acquired cerebral palsy (CP), and to compare clinical outcomes and cause of postneonatally acquired CP between children with and without anomalies.

METHOD

Data were linked between total population CP and congenital anomaly registers in five European and three Australian regions for children born 1991 to 2009 (n=468 children with postneonatally acquired CP; 255 males, 213 females). Data were pooled and children classified into mutually exclusive categories based on type of congenital anomaly. The proportion of children with congenital anomalies was calculated. Clinical outcomes and cause of postneonatally acquired CP were compared between children with and without anomalies.

RESULTS

Major congenital anomalies were reported in 25.6% (95% confidence interval [CI] 21.7-29.9) of children with postneonatally acquired CP. Cardiac anomalies, often severe, were common and present in 14.5% of children with postneonatally acquired CP. Clinical outcomes were not more severe in children with congenital anomalies than those without anomalies. Cause of postneonatally acquired CP differed with the presence of congenital anomalies, with cerebrovascular accidents predominating in the anomaly group. Congenital anomalies were likely associated with cause of postneonatally acquired CP in 77% of children with anomalies.

INTERPRETATION

In this large, international study of children with postneonatally acquired CP, congenital anomalies (particularly cardiac anomalies) were common. Future research should determine specific causal pathways to postneonatally acquired CP that include congenital anomalies to identify opportunities for prevention.

WHAT THIS PAPER ADDS

One-quarter of children with postneonatally acquired cerebral palsy (CP) have a major congenital anomaly. Cardiac anomalies, often severe, are the most common anomalies. Causes of postneonatally acquired CP differ between children with and without congenital anomalies.

Stillbirth in Canada: anachronistic definition and registration processes impede public health surveillance and clinical care

The archaic definition and registration processes for stillbirth currently prevalent in Canada impede both clinical care and public health. The situation is fraught because of definitional problems related to the inclusion of induced abortions at ≥20 weeks’ gestation as stillbirths: widespread uptake of prenatal diagnosis and induced abortion for serious congenital anomalies has resulted in an artefactual temporal increase in stillbirth rates in Canada and placed the country in an unfavourable position in international (stillbirth) rankings. Other problems with the Canadian stillbirth definition and registration processes extend to the inclusion of fetal reductions (for multi-fetal pregnancy) as stillbirths, and the use of inconsistent viability criteria for reporting stillbirth. This paper reviews the history of stillbirth registration in Canada, provides a rationale for updating the definition of fetal death and recommends a new definition and improved processes for fetal death registration. The recommendations proposed are intended to serve as a starting point for reformulating issues related to stillbirth, with the hope that building a consensus regarding a definition and registration procedures will facilitate clinical care and public health.

#postbabyhankypanky: An Empirically Based Knowledge Sharing Initiative About Sex and the Transition to Parenthood

Despite the many sexual concerns experienced by new parents, and their reported desire for more information on this topic, both parents and healthcare providers remain reticent to broach the subject. The goal of this project was to disseminate evidence-based knowledge from our prior research in a way that was accessible, engaging, and would spark further interest and communication for both new parents and healthcare providers. We convened a multidisciplinary advisory group that also involved community parents who provided feedback at all phases of this project. We developed five brief YouTube videos, each featuring a core research finding. Following an empirically supported strategic knowledge translation plan, we disseminated the videos to our target audiences (i.e., expectant and new parents, healthcare providers, educators, and other stakeholders) using social media from February 2018 to November 2019. Data were collected using YouTube analytics and an online survey (convenience sample: N = 225 parents; N = 161 healthcare providers). From the date of the launch, the videos had a reach of 91,766 views from 14 countries, with viewers watching an average of 90% of a video. Overall, quantitative and qualitative survey results suggested that the videos were acceptable and appropriate, and respondents were more confident and comfortable discussing sexual issues (with their partner/with their patients) and would like more information about postpartum sexuality after watching the videos. YouTube videos are an acceptable and effective way to disseminate evidence aimed at raising awareness of factors affecting sexuality in the transition to parenthood.

#postbabyhankypanky: An Empirically Based Knowledge Sharing Initiative About Sex and the Transition to Parenthood

Despite the many sexual concerns experienced by new parents, and their reported desire for more information on this topic, both parents and healthcare providers remain reticent to broach the subject. The goal of this project was to disseminate evidence-based knowledge from our prior research in a way that was accessible, engaging, and would spark further interest and communication for both new parents and healthcare providers. We convened a multidisciplinary advisory group that also involved community parents who provided feedback at all phases of this project. We developed five brief YouTube videos, each featuring a core research finding. Following an empirically supported strategic knowledge translation plan, we disseminated the videos to our target audiences (i.e., expectant and new parents, healthcare providers, educators, and other stakeholders) using social media from February 2018 to November 2019. Data were collected using YouTube analytics and an online survey (convenience sample: N = 225 parents; N = 161 healthcare providers). From the date of the launch, the videos had a reach of 91,766 views from 14 countries, with viewers watching an average of 90% of a video. Overall, quantitative and qualitative survey results suggested that the videos were acceptable and appropriate, and respondents were more confident and comfortable discussing sexual issues (with their partner/with their patients) and would like more information about postpartum sexuality after watching the videos. YouTube videos are an acceptable and effective way to disseminate evidence aimed at raising awareness of factors affecting sexuality in the transition to parenthood.

Maternal antioxidant treatment prevents the adverse effects of prenatal stress on the offspring's brain and behavior

Maternal exposure to stress during pregnancy is associated with an increased risk of psychiatric disorders in the offspring in later life. The mechanisms through which the effects of maternal stress are transmitted to the fetus are unclear, however the placenta, as the interface between mother and fetus, is likely to play a key role. Using a rat model, we investigated a role for placental oxidative stress in conveying the effects of maternal social stress to the fetus and the potential for treatment using a nanoparticle-bound antioxidant to prevent adverse outcomes in the offspring.

Maternal psychosocial stress increased circulating corticosterone in the mother, but not in the fetuses. Maternal stress also induced oxidative stress in the placenta, but not in the fetal brain. Blocking oxidative stress using an antioxidant prevented the prenatal stress-induced anxiety phenotype in the male offspring, and prevented sex-specific neurobiological changes, specifically a reduction in dendrite lengths in the hippocampus, as well as reductions in the number of parvalbumin-positive neurons and GABA receptor subunits in the hippocampus and basolateral amygdala of the male offspring. Importantly, many of these effects were mimicked in neuronal cultures by application of placental-conditioned medium or fetal plasma from stressed pregnancies, indicating molecules released from the placenta may mediate the effects of prenatal stress on the fetal brain. Indeed, both placenta-conditioned medium and fetal plasma contained differentially abundant microRNAs following maternal stress, and their predicted targets were enriched for genes relevant to nervous system development and psychiatric disorders.

The results highlight placental oxidative stress as a key mediator in transmitting the maternal social stress effects on the offspring's brain and behavior, and offer a potential intervention to prevent stress-induced fetal programming of affective disorders.

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Social stress in pregnancy induces oxidative stress but is prevented by antioxidant.

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Prenatal stress induces behavioural, neuroanatomical and neurochemical changes.

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Maternal antioxidant treatment prevents stress-induced effects in the offspring.

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Maternal stress alters the balance of microRNAs secreted from the placenta.

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Placental oxidative stress mediates maternal social stress effects on the offspring.

Database Autopsy: An Efficient and Effective Confidential Enquiry into Maternal Deaths in Canada

BACKGROUND

Maternal death surveillance in Canada relies on hospitalization data, which lacks information on the underlying cause of death. We developed a method for identifying underlying causes of maternal death, and quantified the frequency of maternal death by cause.

METHODS

We used data from the Discharge Abstract Database for fiscal years 2013 to 2017 to identify women who died in Canadian hospitals (excluding Quebec) while pregnant or within 1 year of the end of pregnancy. A sequential narrative based on hospital admission(s) during and after pregnancy was constituted and reviewed to assign the underlying cause of death (based on the World Health Organization's framework). Maternal deaths (i.e., while pregnant or within 42 days after the end of pregnancy) and late maternal deaths (i.e., more than 42 days to a year after the end of pregnancy) were examined separately.

RESULTS

We identified 85 maternal deaths. Direct obstetric causes included 8 deaths (9%) related to complications of spontaneous or induced abortion; 9 (11%), to hypertensive disorders of pregnancy; 15 (18%), to obstetric hemorrhage; 11 (13%), to pregnancy-related infection; 16 (19%), to other obstetric complications; and <5 (<6%), to complications of management. There were 21 (25%) maternal deaths with indirect obstetric causes, and <5 (<6%) with undetermined causes. Of 120 late maternal deaths, 16 (13%) had direct obstetric causes, among them, 9 deaths by suicide (56%). One hundred late maternal deaths (83%) had indirect obstetric causes; and <5 (<4%) had undetermined causes.

CONCLUSIONS

The majority of maternal deaths in Canada have direct obstetric causes, whereas most late maternal deaths have indirect obstetric causes. Suicide is an important direct cause of late maternal death.

Severe maternal morbidity surveillance: Monitoring pregnant women at high risk for prolonged hospitalisation and death

BACKGROUND

There is no international consensus on the definition and components of severe maternal morbidity (SMM).

OBJECTIVES

To propose a comprehensive definition of SMM, to create an empirically justified list of SMM types and subtypes, and to use this to examine SMM in Canada.

METHODS

Severe maternal morbidity was defined as a set of heterogeneous maternal conditions known to be associated with severe illness and with prolonged hospitalisation or high case fatality. Candidate SMM types/subtypes were evaluated using information on all hospital deliveries in Canada (excluding Quebec), 2006-2015. SMM rates for 2012-2016 were quantified as a composite and as SMM types/subtypes. Rate ratios and population attributable fractions (PAF) associated with overall and specific SMM types/subtypes were estimated in relation to length of hospital stay (LOS > 7 days) and case fatality.

RESULTS

There were 22 799 cases of SMM subtypes (among 1 418 545 deliveries) that were associated with a prolonged LOS or high case fatality. Between 2012 and 2016, the composite SMM rate was 16.1 (95% confidence interval [CI] 15.9, 16.3) per 1000 deliveries. Severe pre-eclampsia and HELLP syndrome (514.6 per 100 000 deliveries), and severe postpartum haemorrhage (433.2 per 100 000 deliveries) were the most common SMM types, while case fatality rates among SMM subtypes were highest among women who had cardiac arrest and resuscitation (241.1 per 1000), hepatic failure (147.1 per 1000), dialysis (67.6 per 1000), and cerebrovascular accident/stroke (51.0 per 1000). The PAF for prolonged hospital stay related to SMM was 17.8% (95% CI 17.3, 18.3), while the PAF for maternal death associated with SMM was 88.0% (95% CI 74.6, 94.4).

CONCLUSIONS

The proposed definition of SMM and associated list of SMM subtypes could be used for standardised SMM surveillance, with rate ratios and PAFs associated with specific SMM types/subtypes serving to inform clinical practice and public health policy.

1199 The Accuracy Of A New Sleep Ring Device For Tracking Sleep And Wakefulness Overnight Using Actigraphy

Introduction

THIM is a new consumer ring-like device that can passively monitor sleep overnight using actigraphy. This project aimed to develop the THIM sleep tracking algorithm (Study 1), and test its accuracy against polysomnography (PSG) with another independent sample of good and poor sleepers (Study 2).

Methods

Study 1: 25 healthy individuals (15 females) aged 25.38 years (SD = 6.39) slept overnight in the sleep laboratory with THIM, the Philips Spectrum, the Fitbit Flex, and PSG recording simultaneously. The THIM sleep tracking algorithm was developed by optimising sensitivity and specificity with PSG. Study 2: An additional 20 individuals (14 females) aged 23.22 years (SD = 5.02) slept overnight in the sleep laboratory with the same devices as in Study 1.

Results

Study 1: THIM showed high agreement with PSG for estimating sleep (sensitivity = .91) and reasonably high agreement for wakefulness (specificity = .59). There were no significant differences between PSG and THIM for total sleep time, t(24) = 0.76, p = .46, or sleep efficiency, t(24) = 0.56, p = .58. Study 2: THIM showed high agreement with PSG for estimating sleep (sensitivity = .89) and wakefulness (specificity = .59). Compared to PSG, THIM significantly underestimated total sleep time, t(19) = 2.10, p = .049, and sleep efficiency, t(19) = 2.20, p = .04, by an average of 21.35 minutes (SD = 45.52) and 4.44% (SD = 9.04), respectively.

Conclusion

Together, these studies suggest that THIM is reasonably accurate for monitoring sleep overnight in healthy individuals. Slight modifications to the algorithm and additional sensors could be added to THIM to improve its accuracy. Future research will examine the accuracy of THIM with larger sample sizes and particularly for people with insomnia, with the goal being to incorporate sleep tracking into a mobile-based treatment program for insomnia.

Support

The project was funded in-part by the manufacturers of THIM, Re-Time Pty. Ltd. Additional funding was provided by Flinders University.

1192 The Accuracy of a Novel Sleep Ring Device for Estimating Sleep Onset with Good and Poor Sleepers

Introduction

THIM is a new ring-like sleep device that, if found to accurately measure sleep onset, could be used for a variety of clinical purposes. These include administering a brief but effective treatment for insomnia called Intensive Sleep Retraining, facilitating the optimal 10-minute power nap, and administering Multiple Sleep Latency Tests (MSLTs) outside of the sleep laboratory. This study assessed the accuracy of THIM for measuring sleep onset latency compared to polysomnography (PSG).

Methods

Twenty healthy individuals aged 23.6 years (SD = 4.89) underwent overnight PSG recording whilst using THIM on two nights in the sleep laboratory, one week apart. On each night, participants completed sleep onset trials for four hours whilst monitored via PSG. In these trials, participants attempted to fall asleep whilst responding to vibrations emitted from THIM. Once they failed to respond to two consecutive stimuli, THIM woke them with an intense vibration. Participants had a short break before attempting the next trial.

Results

On average, THIM overestimated sleep onset on the first night by 0.24 minutes (SD = 0.90). On the second night, THIM overestimated sleep onset by 0.82 minutes (SD = 1.31) and this discrepancy was not significantly different to that obtained on the first night, p = .08. The accuracy of THIM did not differ between good sleepers (Insomnia Severity Index (ISI) score &lt; 7) or poor sleepers (ISI score 8-15), p = .98.

Conclusion

The findings suggest that THIM is accurate at estimating sleep onset latency for both good and poor sleepers. The next step is to test THIM outside of the laboratory environment. The goal is to develop an accurate yet practical device that can translate laboratory-based procedures to the home environment, to the benefit of patients and clinicians wanting to improve sleep.

Support

The project was funded in-part by the manufacturers of THIM, Re-Time Pty. Ltd., with additional funding provided by Flinders University.

Systematic Review of the Effectiveness, Safety, and Acceptability of Mifepristone and Misoprostol for Medical Abortion in Low- and Middle-Income Countries

OBJECTIVE

Abortion-related complications remain one of the leading causes of maternal morbidity and mortality worldwide. Nearly half of all abortions are unsafe, and the vast majority of these occur in low- and middle-income countries. The use of mifepristone with misoprostol for medical abortion has been proposed and implemented to improve abortion safety.

DATA SOURCES

A systematic review of the literature was conducted in PubMed, Embase, Cochrane, and CINAHL.

STUDY SELECTION

Criteria for study inclusion were first-trimester abortion, use of mifepristone with misoprostol, and low- or middle-income country status as designated by the World Health Organization.

DATA EXTRACTION

Results for effectiveness, safety, acceptability, and qualitative information were assessed.

DATA SYNTHESIS

The literature search resulted in 181 eligible articles, 52 of which met our criteria for inclusion. A total of 34 publications reported effectiveness data on 25 385 medical abortions. The average effectiveness rate with mifepristone 200 mg and misoprostol 800 µg was 95% up to 63 days gestation. A sensitivity analysis was performed to assume that all women lost to follow-up failed treatment, and the recalculated effectiveness rate remained high at 93%. The average continuing pregnancy rate was 0.6%. A total of 22 publications reported safety and acceptability data on 17 381 medical abortions. Only 0.8% abortions required presentation to hospital, and 87% of patients found the side effects of treatment acceptable. Overall, 95% of women were satisfied with their medical abortion, 94% would choose the method again, and 94% would recommend this method to a friend. A total of 16 publications reported qualitative results and the majority supported positive patient experiences with medical abortion.

CONCLUSIONS

Mifepristone and misoprostol is highly effective, safe, and acceptable to women in low- and middle-income countries, making it a feasible option for reducing maternal morbidity and mortality worldwide.

Advanced ultrasound methods in assessment of carotid plaque instability: a prospective multimodal study

Background

A significant proportion of ischemic strokes are caused by emboli from atherosclerotic, unstable carotid artery plaques. The selection of patients for endarterectomy in current clinical practice is primarily based on the degree of carotid artery stenosis and clinical symptoms. However, the content of the plaque is known to be more important for stroke risk. Intraplaque neovascularization (IPN) has recently emerged as a possible surrogate marker for plaque instability. Neo-microvessels from the adventitial vasa vasorum grow into the full thickness of the vessel wall in an adaptive response to hypoxia, causing subsequent intraplaque haemorrhage and plaque rupture. Conventional ultrasound cannot detect IPN. Contrast-enhanced ultrasound and Superb Microvascular Imaging (SMI), have, however, shown promise in IPN assessment. Recent research using Shear Wave Elastography (SWE) has also reported reduced tissue stiffness in the artery wall (reduced mean Young’s modulus) in unstable compared to stable plaques. The purpose of this study is to identify unstable carotid artery plaques at risk of rupture and future ischemic stroke risk using multimodal assessments.

Methods

Forty five symptomatic and 45 asymptomatic patients > 18 years, with > 50% carotid stenosis referred to Oslo University Hospital ultrasound lab will be included in this on-going project. Patients will undergo contrast enhanced ultrasound, SMI, carotid-MRI and PET-(¹⁸F-FDG). Contrast enhanced ultrasound will be analyzed semi-quantitatively (5-levels visual classification) and quantitatively by plotting time-intensity curve analyses to obtain plaque peak contrast enhancement intensity. Plaques removed at carotid endarterectomy will be assessed histologically and the number of microvessels, areas of inflammation, granulation, calcification, lipid and fibrosis will be measured.

Discussion

This multimodality study will primarily provide information on the clinical value of advanced ultrasound methods (SMI, SWE) for the detection of unstable carotid artery plaque in comparison with other methods including contrast-enhanced ultrasound, carotid-MRI and PET-(¹⁸F-FDG) using histology as the gold standard. Secondly, findings from the methods mentioned above will be related to cerebrovascular symptoms, blood tests (leukocytes, CRP, ESR, lipoproteins and inflammatory markers) and cardiovascular risk factors at inclusion and at 1-year follow-up. The overall aim is to optimize detection of plaque instability which can lead to better preventive decisions and reduced stroke rate.

Prevalence, fecal egg counts, and species identification of gastrointestinal nematodes in replacement dairy heifers in Canada

Information is scarce regarding the epidemiology of gastrointestinal nematodes in Canadian dairy heifers. The objectives of this study were to estimate the prevalence and fecal egg counts of gastrointestinal nematodes in dairy heifers, and using a novel deep-amplicon sequencing approach, to identify the predominant gastrointestinal nematode species in Canadian dairy replacement heifers. Fresh environmental fecal samples (n = 2,369) were collected from replacement heifers on 306 dairy farms across western Canada, Ontario, Québec, and Atlantic Canada. Eggs per gram of feces (EPG) were determined using a modified Wisconsin double-centrifugation sugar flotation technique. Predominant nematode species at the farm level were identified by deep-amplicon nemabiome sequencing of the internal transcribed spacer-2 rDNA locus of nematode third-stage larvae. Generalized estimating equations were used to estimate predicted parasite prevalence and mean EPG in all heifers and by province, allowing for clustering within herds. Individual heifer egg counts ranged from 0 to 141 EPG (median: 0 EPG; interquartile range: 0 to 71 EPG). Gastrointestinal nematodes were detected in 20.9% (95% confidence interval: 17.2 to 24.6%) of heifers, and the predicted mean strongylid EPG accounting for clustering on farms was 1.1 (95% confidence interval: 0.6 to 1.6). The predominant parasite species were Cooperia oncophora and Ostertagia ostertagi. This is the first study in Canada to use a combination of deep-amplicon nemabiome sequencing and a traditional egg count method to describe the epidemiology of gastrointestinal nematodes in dairy heifers.

Severe Maternal Morbidity in Canada: Temporal Trends and Regional Variations, 2003-2016

OBJECTIVE

This study sought to quantify temporal trends and provincial and territorial variations in severe maternal morbidity (SMM) in Canada.

METHODS

The study used data on all hospital deliveries in Canada (excluding Québec) from 2003 to 2016 to examine temporal trends and from 2012 to 2016 to study regional variations. SMM was identified using diagnosis and intervention codes. Contrasts among periods and regions were quantified using rate ratios (RRs) and 95% confidence intervals (CIs). Temporal changes were also assessed using chi-square tests for trend (Canadian Task Force Classification II-1).

RESULTS

The study population included 3 882 790 deliveries between 2003 and 2016 and 1 418 545 deliveries between 2012 and 2016. Severe hemorrhage rates increased from 44.8 in 2003 to 62.4 per 10 000 deliveries in 2012 (P for trend <0.0001) and then declined to 41.8 per 10 000 deliveries in 2016 (P for trend <0.0001). Maternal intensive care unit admission and sepsis rates decreased between 2003 and 2016, whereas rates of stroke, severe uterine rupture, hysterectomy, obstetric embolism, shock, and assisted ventilation increased. Rates of composite SMM in 2012-2016 were higher in Newfoundland and Labrador (RR 1.15; 95% CI 1.04-1.26), Nova Scotia (RR 1.11; 95% CI 1.03-1.19), New Brunswick (RR1.22; 95% CI 1.13-1.32), Manitoba (RR 1.09; 95% CI 1.03-1.15), Saskatchewan (RR 1.15; 95% CI 1.09-1.22), the Yukon (RR 1.74; 95% CI 1.35-2.25), and Nunavut (RR 1.76; 95% CI 1.46-2.11) compared with the rest of Canada, whereas rates were lower in Alberta and British Columbia.

CONCLUSION

This surveillance report helps inform clinical practice and public health policy for improving maternal health in Canada.

The Ghana PrenaBelt trial: a double-blind, sham-controlled, randomised clinical trial to evaluate the effect of maternal positional therapy during third-trimester sleep on birth weight

OBJECTIVE

To evaluate the effect, on birth weight and birth weight centile, of use of the PrenaBelt, a maternal positional therapy device, during sleep in the home setting throughout the third trimester of pregnancy.

DESIGN

A double-blind, sham-controlled, randomised clinical trial.

SETTING

Conducted from September 2015 to May 2016, at a single, tertiary-level centre in Accra, Ghana.

PARTICIPANTS

Two-hundred participants entered the study. One-hundred-eighty-one participants completed the study. Participants were women, 18 to 35 years of age, with low-risk, singleton, pregnancies in their third-trimester, with body mass index <35 kg/m² at the first antenatal appointment for the index pregnancy and without known foetal abnormalities, pregnancy complications or medical conditions complicating sleep.

INTERVENTIONS

Participants were randomised by computer-generated, one-to-one, simple randomisation to receive either the PrenaBelt or sham-PrenaBelt. Participants were instructed to wear their assigned device to sleep every night for the remainder of their pregnancy (approximately 12 weeks in total) and were provided a sleep diary to track their use. Allocation concealment was by unmarked, security-tinted, sealed envelopes. Participants and the outcomes assessor were blinded to allocation.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcomes were birth weight and birth weight centile. Secondary outcomes included adherence to using the assigned device nightly, sleeping position, pregnancy outcomes and feedback from participants and maternity personnel.

RESULTS

One-hundred-sixty-seven participants were included in the primary analysis. The adherence to using the assigned device nightly was 56%. The mean ±SD birth weight in the PrenaBelt group (n=83) was 3191g±483 and in the sham-PrenaBelt group (n=84) was 3081g±484 (difference 110 g, 95% CI -38 to 258, p=0.14). The median (IQR) customised birth weight centile in the PrenaBelt group was 43% (18 to 67) and in the sham-PrenaBelt group was 31% (14 to 58) (difference 7%, 95% CI -2 to 17, p=0.11).

CONCLUSIONS

The PrenaBelt did not have a statistically significant effect on birth weight or birth weight centile in comparison to the sham-PrenaBelt.

TRIAL REGISTRATION NUMBER

NCT02379728.