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Introduction: Maternal perception of fetal movements during pregnancy are reassuring; however, the perception of a reduction in movements are concerning to women and known to be associated with increased odds of late stillbirth. Prior to full term, little evidence exists to provide guidelines on how to proceed unless there is an immediate risk to the fetus. Increased strength of movement is the most commonly reported perception of women through to full term, but perception of movement is also hypothesized to be influenced by fetal size. The study aimed to assess the pattern of maternal perception of strength and frequency of fetal movement by gestation and customized birthweight quartile in ongoing pregnancies. A further aim was to assess the association of stillbirth to perception of fetal movements stratified by customized birthweight quartile. Material and methods: This analysis was an individual participant data meta‐analyses of five case–control studies investigating factors associated with stillbirth. The dataset included 851 cases of women with late stillbirth (>28 weeks' gestation) and 2257 women with ongoing pregnancies who then had a liveborn infant. Results: The frequency of prioritized fetal movement from 28 weeks' gestation showed a similar pattern for each quartile of birthweight with increased strength being the predominant perception of fetal movement through to full term. The odds of stillbirth associated with reduced fetal movements was increased in all quartiles of customized birthweight centiles but was notably greater in babies in the lowest two quartiles (Q1: adjusted OR: 9.34, 95% CI: 5.43, 16.06 and Q2: adjusted OR: 6.11, 95% CI: 3.11, 11.99). The decreased odds associated with increased strength of movement was present for all customized birthweight quartiles (adjusted OR range: 0.25–0.56). Conclusions: Increased strength of fetal movements in late pregnancy is a positive finding irrespective of fetal size. However, reduced fetal movements are associated with stillbirth, and more so when the fetus is small. [ABSTRACT FROM AUTHOR]

Objective: Identify independent and novel risk factors for late‐preterm (28–36 weeks) and term (≥37 weeks) stillbirth and explore development of a risk‐prediction model. Design: Secondary analysis of an Individual Participant Data (IPD) meta‐analysis investigating modifiable stillbirth risk factors. Setting: An IPD database from five case–control studies in New Zealand, Australia, the UK and an international online study. Population: Women with late‐stillbirth (cases, n = 851), and ongoing singleton pregnancies from 28 weeks' gestation (controls, n = 2257). Methods: Established and novel risk factors for late‐preterm and term stillbirth underwent univariable and multivariable logistic regression modelling with multiple sensitivity analyses. Variables included maternal age, body mass index (BMI), parity, mental health, cigarette smoking, second‐hand smoking, antenatal‐care utilisation, and detailed fetal movement and sleep variables. Main outcome measures: Independent risk factors with adjusted odds ratios (aOR) for late‐preterm and term stillbirth. Results: After model building, 575 late‐stillbirth cases and 1541 controls from three contributing case–control studies were included. Risk factor estimates from separate multivariable models of late‐preterm and term stillbirth were compared. As these were similar, the final model combined all late‐stillbirths. The single multivariable model confirmed established demographic risk factors, but additionally showed that fetal movement changes had both increased (decreased frequency) and reduced (hiccoughs, increasing strength, frequency or vigorous fetal movements) aOR of stillbirth. Poor antenatal‐care utilisation increased risk while more‐than‐adequate care was protective. The area‐under‐the‐curve was 0.84 (95% CI 0.82–0.86). Conclusions: Similarities in risk factors for late‐preterm and term stillbirth suggest the same approach for risk‐assessment can be applied. Detailed fetal movement assessment and inclusion of antenatal‐care utilisation could be valuable in late‐stillbirth risk assessment. This article includes Author Insights, a video abstract available at: https://players.brightcove.net/3806881048001/default%5fdefault/index.html?videoId=6320088103112. Linked article: This article is commented on by J. Jardine, pp. 1071 in this issue. To view this mini commentary visit https://doi.org/10.1111/1471‐0528.17469. [ABSTRACT FROM AUTHOR]

Presentations for decreased fetal movements comprise a significant proportion of acute antenatal assessments. Decreased fetal movements are associated with increased likelihood of adverse pregnancy outcomes including stillbirth. Consensus-based guidelines recommend pregnant women routinely receive information about fetal movements, but practice is inconsistent, and the information shared is frequently not evidence-based. There are also knowledge gaps about the assessment and management of fetal movement concerns. Women have indicated that they would like more accurate information about what to expect regarding fetal movements. Historically, fetal movement information has focussed on movement counts. This is problematic, as the number of fetal movements perceived varies widely between pregnant women, and no set number of movements has been established as a reliable indicator of fetal wellbeing. Of late, maternity care providers have also advised women to observe their baby's movement pattern, and promptly present if they notice a change. However, normal fetal movement patterns are rarely defined. Recently, a body of research has emerged relating to maternal perception of fetal movement features such as strength, presence of hiccups, and diurnal pattern as indicators of fetal wellbeing in addition to frequency. Sharing comprehensive and gestation-appropriate information about fetal movements may be more satisfying for women, empowering women to identify for themselves when their baby is doing well, and importantly when additional assessment is needed. We propose a conversational approach to fetal movement information sharing, focusing on fetal movement strength, frequency, circadian pattern, and changes with normal fetal development, tailored to the individual. [ABSTRACT FROM AUTHOR]

Background: Late stillbirth continues to affect 3-4/1000 pregnancies in high-resource settings, with even higher rates in low-resource settings. Reduced foetal movements are frequently reported by women prior to foetal death, but there remains a poor understanding of the reasons and how to deal with this symptom clinically, particularly during the preterm phase of gestation. We aimed to determine which women are at the greatest odds of stillbirth in relation to the maternal report of foetal movements in late pregnancy (≥ 28 weeks' gestation).Methods: This is an individual participant data meta-analysis of all identified case-control studies of late stillbirth. Studies included in the IPD were two from New Zealand, one from Australia, one from the UK and an internet-based study based out of the USA. There were a total of 851 late stillbirths, and 2257 controls with ongoing pregnancies.Results: Increasing strength of foetal movements was the most commonly reported (> 60%) pattern by women in late pregnancy, which were associated with a decreased odds of late stillbirth (adjusted odds ratio (aOR) = 0.20, 95% CI 0.15 to 0.27). Compared to no change in strength or frequency women reporting decreased frequency of movements in the last 2 weeks had increased odds of late stillbirth (aOR = 2.33, 95% CI 1.73 to 3.14). Interaction analysis showed increased strength of movements had a greater protective effect and decreased frequency of movements greater odds of late stillbirth at preterm gestations (28-36 weeks' gestation). Foetal hiccups (aOR = 0.45, 95% CI 0.36 to 0.58) and regular episodes of vigorous movement (aOR = 0.67, 95% CI 0.52 to 0.87) were associated with decreased odds of late stillbirth. A single episode of unusually vigorous movement was associated with increased odds (aOR = 2.86, 95% CI 2.01 to 4.07), which was higher in women at term.Conclusions: Reduced foetal movements are associated with late stillbirth, with the association strongest at preterm gestations. Foetal hiccups and multiple episodes of vigorous movements are reassuring at all gestations after 28 weeks' gestation, whereas a single episode of vigorous movement is associated with stillbirth at term. [ABSTRACT FROM AUTHOR]

Background and objectives: Sleep-disordered breathing (SDB) affects up to one third of women during late pregnancy and is associated with adverse pregnancy outcomes, including hypertension, diabetes, impaired fetal growth, and preterm birth. However, it is unclear if SDB is associated with late stillbirth (≥28 weeks' gestation). The aim of this study was to investigate the relationship between self-reported symptoms of SDB and late stillbirth. Methods: Data were obtained from five case-control studies (cases 851, controls 2257) from New Zealand (2 studies), Australia, the United Kingdom, and an international study. This was a secondary analysis of an individual participant data meta-analysis that investigated maternal going-to-sleep position and late stillbirth, with a one-stage approach stratified by study and site. Inclusion criteria: singleton, non-anomalous pregnancy, ≥28 weeks' gestation. Sleep data ('any' snoring, habitual snoring ≥3 nights per week, the Berlin Questionnaire [BQ], sleep quality, sleep duration, restless sleep, daytime sleepiness, and daytime naps) were collected by self-report for the month before stillbirth. Multivariable analysis adjusted for known major risk factors for stillbirth, including maternal age, body mass index (BMI kg/m2), ethnicity, parity, education, marital status, pre-existing hypertension and diabetes, smoking, recreational drug use, baby birthweight centile, fetal movement, supine going-to-sleep position, getting up to use the toilet, measures of SDB and maternal sleep patterns significant in univariable analysis (habitual snoring, the BQ, sleep duration, restless sleep, and daytime naps). Registration number: PROSPERO, CRD42017047703. Results: In the last month, a positive BQ (adjusted odds ratio [aOR] 1.44, 95% confidence interval [CI] 1.02–2.04), sleep duration >9 hours (aOR 1.82, 95% CI 1.14–2.90), daily daytime naps (aOR 1.52, 95% CI 1.02–2.28) and restless sleep greater than average (aOR 0.62, 95% CI 0.44–0.88) were independently related to the odds of late stillbirth. 'Any' snoring, habitual snoring, sleep quality, daytime sleepiness, and a positive BQ excluding the BMI criterion, were not associated. Conclusion: A positive BQ, long sleep duration >9 hours, and daily daytime naps last month were associated with increased odds of late stillbirth, while sleep that is more restless than average was associated with reduced odds. Pregnant women may be reassured that the commonly reported restless sleep of late pregnancy may be physiological and associated with a reduced risk of late stillbirth. [ABSTRACT FROM AUTHOR]

Prioritisation of stillbirth research in high-income countries is required to address preventable stillbirth. However, concern is raised by ethics committees, maternity providers and families, when pregnant and bereaved women are approached to participate. Our aim was to 1) assess factors influencing recruitment in a multicentre case-control stillbirth study and 2) gain insight into how women felt about their participation. Eligible women were contacted through maternity providers from seven New Zealand health regions in 2011-2015. Cases had a recent singleton non-anomalous late stillbirth (≥28 weeks' gestation). Controls were randomly selected and matched for region and gestation. Participants were interviewed by a research midwife and given a feedback form asking their views about participation. Feedback was evaluated using thematic analysis. 169 (66.5%) of 254 eligible cases and 569 (62.2%) of 915 eligible controls were recruited. Non-participants consisted of 263 (22.5% of eligible) women who declined, 108 (9.2% of eligible) uncontactable women, and 60 (5.1% of eligible) women declined by the maternity provider, with no significant differences between the proportion of non-participating cases and controls in each of these three categories. The majority (63.2%) of women did not provide a specific reason for non-participation. Written feedback was provided by 111 participants (cases 15.3%, controls 14.9%) and all described their involvement positively. Feedback themes identified were 'motivation to participate,' 'ease of participation,' and 'post-participation positivity.' Identification of recruitment barriers and our reassuring participant feedback may assist women's participation in future research and support progress towards stillbirth prevention. [ABSTRACT FROM AUTHOR]

Background and objectives: Encouraging awareness of fetal movements is a common strategy used to prevent stillbirths. Information provided to pregnant women about fetal movements is inconsistent perhaps due to limited knowledge about normal fetal movement patterns in healthy pregnancies. We aimed to describe maternally perceived fetal movement strength, frequency, and pattern in late pregnancy in women with subsequent normal outcomes. Methods: Participants were ≥28 weeks’ gestation, with a non-anomalous, singleton pregnancy who had been randomly selected from hospital booking lists and had consented to participate. Fetal movement data was gathered during pregnancy via a questionnaire administered face-to-face by research midwives. Participants remained eligible for the study if they subsequently gave birth to a live, appropriate-for-gestational-age baby at ≥37 weeks. Results: Participants were 274 women, with normal pregnancy outcomes. The majority (59.3%, n = 162) of women reported during antenatal interview that the strength of fetal movements had increased in the preceding two weeks. Strong fetal movements were felt by most women in the evening (72.8%, n = 195) and at night-time including bedtime (74.5%, n = 199). The perception of fetal hiccups was also reported by most women (78.8%). Women were more likely to perceive moderate or strong fetal movements when sitting quietly compared with other activities such as having a cold drink or eating. Conclusions: Our data support informing women in the third trimester that as pregnancy advances it is normal to perceive increasingly strong movement, episodes of movements that are more vigorous than usual, fetal hiccups, and a diurnal pattern involving strong fetal movement in the evening. This information may help pregnant women to better characterise normal fetal movement and appropriately seek review when concerned about fetal movements. Care providers should be responsive to concerns about decreased fetal movements in the evening, as this is unusual. [ABSTRACT FROM AUTHOR]

Background: For parents who experience stillbirth, knowing the cause of their baby's death is important. A post mortem examination is the gold standard investigation, but little is known about what may influence parents' decisions to accept or decline. Aim: We aimed to identify factors influencing maternal decision‐making about post mortem examination after late stillbirth. Methods: In the New Zealand Multicentre Stillbirth Study, 169 women with singleton pregnancies, no known abnormality at recruitment, and late stillbirth (≥28weeks gestation), from seven health regions were interviewed within six weeks of birth. The purpose of this paper was to explore factors related to post mortem examination decision‐making and the reasons for declining. We asked women if they would make the same decision again. Results: Maternal decision to decline a post mortem (70/169, 41.4%) was more common among women of Māori (adjusted odds ratio (aOR) 4.99 95% confidence interval (CI) 1.70–14.64) and Pacific (aOR 3.94 95% CI 1.47–10.54) ethnicity compared to European, and parity two or more (aOR 2.95 95% CI 1.14–7.62) compared to primiparous. The main reason for declining was that women 'did not want baby to be cut'. Ten percent (7/70) who declined said they would not make this decision again. No woman who consented regretted her decision. Conclusion: Ethnic differences observed in women's post mortem decision‐making should be further explored in future studies. Providing information of the effect of post mortem on the baby's body and the possible emotional benefits of a post mortem may assist women faced with this decision in the future. [ABSTRACT FROM AUTHOR]

Abstract Background Second-degree tears are the most common form of perineal trauma occurring after vaginal birth managed by New Zealand midwives, although little is known about midwives' perineal practice. Aim The aim of this study was to identify how midwives managed the last second-degree perineal tear they treated and the level to which their practice reflects National Institute for Health and Care Excellence guidelines. Methods An (anonymous) online survey was conducted over a six-week period in 2013. New Zealand midwives who self-identified as currently practising perineal management and could recall management of the last second-degree tear they treated were included in the analysis. Findings Of those invited, 645 (57.1% self-employed, 42.9% employed) were eligible and completed surveys. Self-employed midwives reported greater confidence (88.0% vs 74.4%, p < 0.001) and more recent experience (85.1% vs 57.4%, p < 0.001) with perineal repair than employed midwives. Midwives who left the last second-degree tear unsutured (7.3%) were more likely to report low confidence (48.9% vs 15.4%, p < 0.001) and less recent experience with repair (53.2% vs 24.7%, p < 0.001), and were less likely to report a digital-rectal examination (10.6% vs 49.0%, p < 0.001), compared to midwives who sutured. Care consistent with evidence-based guidelines (performing a digital-rectal examination, 59.4% vs 49.3% p = 0.005; optimal suturing techniques, 62.2% vs 48.7%, p = 0.001) was associated with recent perineal education. Conclusions Midwives' management of the last second-degree perineal tear is variable and influenced by factors including: employment status, experience, confidence, and perineal education. There is potential for improvement in midwives' management through increased uptake of evidence-based guidelines and through ongoing education. [ABSTRACT FROM AUTHOR]

Introduction Accumulating evidence has shown an association between maternal supine going-to-sleep position and stillbirth in late pregnancy. Advising women not to go-to-sleep on their back can potentially reduce late stillbirth rate by 9%. However, the association between maternal right-sided going-to-sleep position and stillbirth is inconsistent across studies. Furthermore, individual studies are underpowered to investigate interactions between maternal going-to-sleep position and fetal vulnerability, which is potentially important for producing clear and tailored public health messages on safe goingto- sleep position. We will use individual participant data (IPD) from existing studies to assess whether right-side and supine going-to-sleep positions are independent risk factors for late stillbirth and to test the interaction between going-to-sleep position and fetal vulnerability. Methods and analysis An IPD meta-analysis approach will be used using the Cochrane Collaboration-endorsed methodology. We will identify case-control and prospective cohort studies and randomised trials which collected maternal going-to-sleep position data and pregnancy outcome data that included stillbirth. The primary outcome is stillbirth. A one stage procedure meta-analysis, stratified by study with adjustment of a priori confounders will be carried out. Ethics and dissemination The IPD meta-analysis has obtained central ethics approval from the New Zealand Health and Disability Ethics Committee, ref: NTX/06/05/054/AM06. Individual studies should also have ethical approval from relevant local ethics committees. Interpretation of the results will be discussed with consumer representatives. Results of the study will be published in peer-reviewed journals and presented at international conferences. [ABSTRACT FROM AUTHOR]

Background: The Auckland Stillbirth study demonstrated a two-fold increased risk of late stillbirth for women who did not go to sleep on their left side. Two further studies have confirmed an increased risk of late stillbirth with supine sleep position. As sleep position is modifiable, we surveyed self-reported late pregnancy sleep position, knowledge about sleep position, and views about changing going-to-sleep position.Methods: Participants in this 2014 survey were pregnant women (n = 377) in their third trimester from South Auckland, New Zealand, a multi-ethnic and predominantly low socio-economic population. An ethnically-representative sample was obtained using random sampling. Multivariable logistic regression was performed to identify factors independently associated with non-left sided going-to-sleep position in late pregnancy.Results: Respondents were 28 to 42 weeks' gestation. Reported going-to-sleep position in the last week was left side (30%), right side (22%), supine (3%), either side (39%) and other (6%). Two thirds (68%) reported they had received advice about sleep position. Non-left sleepers were asked if they would be able to change to their left side if it was better for their baby; 87% reported they would have little or no difficulty changing. Women who reported a non-left going-to-sleep position were more likely to be of Maori (aOR 2.64 95% CI 1.23-5.66) or Pacific (aOR 2.91 95% CI 1.46-5.78) ethnicity; had a lower body mass index (BMI) (aOR 0.93 95% CI 0.89-0.96); and were less likely to sleep on the left-hand side of the bed (aOR 3.29 95% CI 2.03-5.32).Conclusions: Maternal going-to-sleep position in the last week was side-lying in 91% of participants. The majority had received advice to sleep on their side or avoid supine sleep position. Sleeping on the left-hand side of the bed was associated with going-to-sleep on the left side. Most non-left sleepers reported their sleeping position could be modified to the left side suggesting a public health intervention about sleep position is likely to be feasible in other multi-ethnic communities. [ABSTRACT FROM AUTHOR]

Objective: Our objective was to test the primary hypothesis that maternal non-left, in particular supine going-to-sleep position, would be a risk factor for late stillbirth (≥28 weeks of gestation). Methods: A multicentre case-control study was conducted in seven New Zealand health regions, between February 2012 and December 2015. Cases (n = 164) were women with singleton pregnancies and late stillbirth, without congenital abnormality. Controls (n = 569) were women with on-going singleton pregnancies, randomly selected and frequency matched for health region and gestation. The primary outcome was adjusted odds of late stillbirth associated with self-reported going-to-sleep position, on the last night. The last night was the night before the late stillbirth was thought to have occurred or the night before interview for controls. Going-to-sleep position on the last night was categorised as: supine, left-side, right-side, propped or restless. Multivariable logistic regression adjusted for known confounders. Results: Supine going-to-sleep position on the last night was associated with increased late stillbirth risk (adjusted odds ratios (aOR) 3.67, 95% confidence interval (CI) 1.74 to 7.78) with a population attributable risk of 9.4%. Other independent risk factors for late stillbirth (aOR, 95% CI) were: BMI (1.04, 1.01 to 1.08) per unit, maternal age ≥40 (2.88, 1.31 to 6.32), birthweight <10th customised centile (2.76, 1.59 to 4.80), and <6 hours sleep on the last night (1.81, 1.14 to 2.88). The risk associated with supine-going-to-sleep position was greater for term (aOR 10.26, 3.00 to 35.04) than preterm stillbirths (aOR 3.12, 0.97 to 10.05). Conclusions: Supine going-to-sleep position is associated with a 3.7 fold increase in overall late stillbirth risk, independent of other common risk factors. A public health campaign encouraging women not to go-to-sleep supine in the third trimester has potential to reduce late stillbirth by approximately 9%. [ABSTRACT FROM AUTHOR]

Purpose This survey investigated late pregnancy maternal sleep practices and ability to modify sleep position in order to generate information on which to base future public health messages about optimal going-to-sleep position. Research Question What are the sleep practices of women in late pregnancy, and what are their views about changing going-to-sleep position if this was recommended? Significance Maternal sleep position in late pregnancy is a modifiable risk factor for late stillbirth. A 2011 study from Auckland, New Zealand, was the first to demonstrate a 2-fold increased risk for women who did not go to sleep on their left side the night before the fetus was thought to have died, with the highest risk for women who settled to sleep supine. This association has since been confirmed by an Australian and Ghanaian study and a New Zealand multicentre study. Methods A random sample of ethnically-representative women (N = 377), between 28 and 42 weeks' gestation, were surveyed in 2014 in South Auckland, New Zealand, a multicultural and socioeconomically disadvantaged population with an increased risk of stillbirth. Factors independently associated with non-left side going-to-sleep position in late pregnancy were identified using multivariable logistic regression. Results Self-reported going-to-sleep position in the last week was left (30%), right (22%), supine (3%), either side (39%), and other (6%). The majority (68%) had received advice about pregnancy sleep position. A non-left position was more likely to be reported by women of Maori (adjusted odds ratio [aOR], 2.64; 95% confidence interval [CI], 1.23-5.66) or Pacific (aOR, 2.91; 95% CI, 1.46-5.78) ethnicity, and those who did not sleep on the left-hand side of the bed (aOR, 3.29; 95% CI, 2.03-5.32). Most (87%) non-left sleepers reported that they would have minimal difficulty changing to going to sleep on their left side in late pregnancy if this was better for their fetus. Discussion The results from this survey suggest that going-to-sleep position in late pregnancy is likely to be readily modifiable. This suggests that a public health intervention, about the importance of optimal late pregnancy going-to-sleep position to optimise fetal well-being, is likely to be feasible in similar communities with an increased risk of stillbirth. [ABSTRACT FROM AUTHOR]

Objective: Identify independent and novel risk factors for late-preterm (28-36 weeks) and term (≥37 weeks) stillbirth and explore development of a risk-prediction model., Design: Secondary analysis of an Individual Participant Data (IPD) meta-analysis investigating modifiable stillbirth risk factors., Setting: An IPD database from five case-control studies in New Zealand, Australia, the UK and an international online study., Population: Women with late-stillbirth (cases, n = 851), and ongoing singleton pregnancies from 28 weeks' gestation (controls, n = 2257)., Methods: Established and novel risk factors for late-preterm and term stillbirth underwent univariable and multivariable logistic regression modelling with multiple sensitivity analyses. Variables included maternal age, body mass index (BMI), parity, mental health, cigarette smoking, second-hand smoking, antenatal-care utilisation, and detailed fetal movement and sleep variables., Main Outcome Measures: Independent risk factors with adjusted odds ratios (aOR) for late-preterm and term stillbirth., Results: After model building, 575 late-stillbirth cases and 1541 controls from three contributing case-control studies were included. Risk factor estimates from separate multivariable models of late-preterm and term stillbirth were compared. As these were similar, the final model combined all late-stillbirths. The single multivariable model confirmed established demographic risk factors, but additionally showed that fetal movement changes had both increased (decreased frequency) and reduced (hiccoughs, increasing strength, frequency or vigorous fetal movements) aOR of stillbirth. Poor antenatal-care utilisation increased risk while more-than-adequate care was protective. The area-under-the-curve was 0.84 (95% CI 0.82-0.86)., Conclusions: Similarities in risk factors for late-preterm and term stillbirth suggest the same approach for risk-assessment can be applied. Detailed fetal movement assessment and inclusion of antenatal-care utilisation could be valuable in late-stillbirth risk assessment., (© 2023 The Authors. BJOG: An International Journal of Obstetrics and Gynaecology published by John Wiley & Sons Ltd.)

Introduction: A 'Sleep-On-Side When Baby's Inside' public health campaign was initiated in New Zealand in 2018. This was in response to evidence that maternal supine going-to-sleep position was an independent risk factor for stillbirth from 28 weeks' gestation. We evaluated the success of the campaign on awareness and modification of late pregnancy going-to-sleep position through nationwide surveys., Methods and Analysis: Two web-based cross-sectional surveys were conducted over 12 weeks in 2019-2020 in a sample of (1) pregnant women ≥28 weeks, primary outcome of going-to-sleep position; and (2) health professionals providing pregnancy care, primary outcome of knowledge of going-to-sleep position and late stillbirth risk. Univariable logistic regression was performed to identify factors associated with supine going-to-sleep position., Discussion: The survey of pregnant women comprised 1633 eligible participants. Going-to-sleep position last night was supine (30, 1.8%), non-supine (1597, 97.2%) and no recall (16, 1.0%). Supine position had decreased from 3.9% in our previous New Zealand-wide study (2012-2015). Most women (1412, 86.5%) had received sleep-on-side advice with no major resultant worry (1276, 90.4%). Two-thirds (918, 65.0%) had changed their going-to-sleep position based on advice, with most (611 of 918, 66.5%) reporting little difficulty. Supine position was associated with Māori (OR 5.05, 95% CI 2.10 to 12.1) and Asian-non-Indian (OR 4.20, 95% CI 1.27 to 13.90) ethnicity; single (OR 10.98, 95% CI 4.25 to 28.42) and cohabitating relationship status (OR 2.69, 95% CI 1.09 to 6.61); hospital-based maternity provider (OR 2.55, 95% CI 1.07 to 6.10); education overseas (OR 3.92, 95% CI 1.09 to 14.09) and primary-secondary level (OR 2.80, 95% CI 1.32 to 6.08); and not receiving sleep-on-side advice (OR 6.70, 95% CI 3.23 to 13.92). The majority of health professionals (709 eligible participants) reported awareness of supine going-to-sleep position and late stillbirth risk (543, 76.6%)., Conclusion: Most pregnant women had received and implemented sleep-on-side advice without major difficulty or concern. Some groups of women may need a tailored approach to acquisition of going-to-sleep position information., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Introduction: Accumulating evidence has shown an association between maternal supine going-to-sleep position and stillbirth in late pregnancy. Advising women not to go-to-sleep on their back can potentially reduce late stillbirth rate by 9%. However, the association between maternal right-sided going-to-sleep position and stillbirth is inconsistent across studies. Furthermore, individual studies are underpowered to investigate interactions between maternal going-to-sleep position and fetal vulnerability, which is potentially important for producing clear and tailored public health messages on safe going-to-sleep position. We will use individual participant data (IPD) from existing studies to assess whether right-side and supine going-to-sleep positions are independent risk factors for late stillbirth and to test the interaction between going-to-sleep position and fetal vulnerability., Methods and Analysis: An IPD meta-analysis approach will be used using the Cochrane Collaboration-endorsed methodology. We will identify case-control and prospective cohort studies and randomised trials which collected maternal going-to-sleep position data and pregnancy outcome data that included stillbirth. The primary outcome is stillbirth. A one stage procedure meta-analysis, stratified by study with adjustment of a priori confounders will be carried out., Ethics and Dissemination: The IPD meta-analysis has obtained central ethics approval from the New Zealand Health and Disability Ethics Committee, ref: NTX/06/05/054/AM06. Individual studies should also have ethical approval from relevant local ethics committees. Interpretation of the results will be discussed with consumer representatives. Results of the study will be published in peer-reviewed journals and presented at international conferences., Prospero Registration Number: CRD42017047703., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)