Association between maternal sleep practices and late stillbirth - findings from a stillbirth case-control study

Impact of maternal posture on fetal physiology in human pregnancy: a narrative review

In numerous medical conditions, including pregnancy, gravity and posture interact to impact physiology and pathophysiology. Recent investigations, for example, pertaining to maternal sleeping posture during the third trimester and possible impact on fetal growth and stillbirth risk highlight the importance and potential clinical implications of the subject. In this review, we provide an extensive discussion of the impact of maternal posture on fetal physiology from conception to the postpartum period in human pregnancy. We conducted a systematic literature search of the MEDLINE database and identified 242 studies from 1991 through 2021, inclusive, that met our inclusion criteria. Herein, we provide a synthesis of the resulting literature. In the first section of the review, we group the results by the impact of maternal posture at rest on the cervix, uterus, placenta, umbilical cord, amniotic fluid, and fetus. In the second section of the review, we address the impact on fetal-related outcomes of maternal posture during various maternal activities (e.g., sleep, work, exercise), medical procedures (e.g., fertility, imaging, surgery), and labor and birth. We present the published literature, highlight gaps and discrepancies, and suggest future research opportunities and clinical practice changes. In sum, we anticipate that this review will shed light on the impact of maternal posture on fetal physiology in a manner that lends utility to researchers and clinicians who are working to improve maternal, fetal, and child health.

Maternal rest improves growth in small-for-gestational-age fetuses (<10th percentile)

BACKGROUND

Optimal management of fetuses diagnosed as small for gestational age based on an estimated fetal weight of <10th percentile represents a major clinical problem. The standard approach is to increase fetal surveillance with serial biometry and antepartum testing to assess fetal well-being and timing of delivery. Observational studies have indicated that maternal rest in the left lateral position improves maternal cardiac output and uterine blood flow. However, maternal bed rest has not been recommended based on the results of a randomized clinical trial that showed that maternal rest does not improve fetal growth in small-for-gestational-age fetuses. This study was conducted to revisit this question.

OBJECTIVE

This study aimed to determine whether maternal bed rest was associated with an increase in the fetal biometric parameters that reflect growth after the diagnosis of a small-for-gestational-age fetus.

STUDY DESIGN

A retrospective study was conducted on fetuses who were diagnosed as small for gestational age because of an estimated fetal weight of <10th percentile for gestational age. The mothers were asked to rest in the left lateral recumbent position. Fetal biometry was performed 2 weeks after the diagnosis. All fetuses before entry into the study had a previous ultrasound that demonstrated an estimated fetal weight of >10th percentile. To assess the response to bed rest, the change in fetal biometric parameters (estimated fetal weight, head circumference, abdominal circumference, and femur length) after the recommendation of bed rest was computed for 2 periods: (1) before the diagnosis of a weight of <10th percentile vs at the time of diagnosis of a weight of <10th percentile and (2) at the time of diagnosis of a weight of <10th percentile vs 2 weeks after maternal bed rest. For repeated measures, proportions were compared using the McNemar test, and percentile values were compared using the Kruskal-Wallis test. A P value of <.05 was considered significant. To describe changes in the estimated fetal weight without bed rest, 2 control groups in which the mothers were not placed on bed rest after the diagnosis of a small-for-gestational-age fetus were included.

RESULTS

A total of 265 fetuses were observed before and after maternal bed rest. The following were observed in this study: (1) after 2 weeks of maternal rest, 199 of 265 fetuses (75%) had a fetal weight of >10th percentile; (2) the median fetal weight percentile increased from 6.8 (interquartile range, 4.4-8.4) to 18.0 (interquartile range, 9.5-29.5) after 2 weeks of bed rest; (3) similar trends were noted for the head circumference, abdominal circumference, and femur length. In the groups of patients who were not asked to be on bed rest, a reassignment to a weight of >10th percentile at a follow-up examination only occurred in 7 of 37 patients (19%) in the Texas-Michigan group and 13 of 111 patients (12%) in the Colorado group compared with the bed rest group (199/265 [75%]) (P<.001).

CONCLUSION

Patients who were prescribed 2 weeks of bed rest after the diagnosis of a fetal weight of <10th percentile had an increase in weight of >10th percentile in 199 of 265 fetuses (75%). This increase in fetal weight was significantly higher than that in the 2 control groups in which bed rest was not prescribed. This observation suggests that bed rest improves fetal growth in a subset of patients.

Lifestyle and sociodemographic risk factors for stillbirth by region of residence in South Australia: a retrospective cohort study

BACKGROUND

Stillbirth rates remain a global priority and in Australia, progress has been slow. Risk factors of stillbirth are unique in Australia due to large areas of remoteness, and limited resource availability affecting the ability to identify areas of need and prevalence of factors associated with stillbirth. This retrospective cohort study describes lifestyle and sociodemographic factors associated with stillbirth in South Australia (SA), between 1998 and 2016.

METHODS

All restigered births in SA between 1998 ad 2016 are included. The primary outcome was stillbirth (birth with no signs of life ≥ 20 weeks gestation or ≥ 400 g if gestational age was not reported). Associations between stillbirth and lifestyle and sociodemographic factors were evaluated using multivariable logistic regression and described using adjusted odds ratios (aORs).

RESULTS

A total of 363,959 births (including 1767 stillbirths) were included. Inadequate antenatal care access (assessed against the Australian Pregnancy Care Guidelines) was associated with the highest odds of stillbirth (aOR 3.93, 95% confidence interval (CI) 3.41-4.52). Other factors with important associations with stillbirth were plant/machine operation (aOR, 1.99; 95% CI, 1.16-2.45), birthing person age ≥ 40 years (aOR, 1.92; 95% CI, 1.50-2.45), partner reported as a pensioner (aOR, 1.83; 95% CI, 1.12-2.99), Asian country of birth (aOR, 1.58; 95% CI, 1.19-2.10) and Aboriginal/Torres Strait Islander status (aOR, 1.50; 95% CI, 1.20-1.88). The odds of stillbirth were increased in regional/remote areas in association with inadequate antenatal care (aOR, 4.64; 95% CI, 2.98-7.23), birthing age 35-40 years (aOR, 1.92; 95% CI, 1.02-3.64), Aboriginal and/or Torres Strait Islander status (aOR, 1.90; 95% CI, 1.12-3.21), paternal occupations: tradesperson (aOR, 1.69; 95% CI, 1.17-6.16) and unemployment (aOR, 4.06; 95% CI, 1.41-11.73).

CONCLUSION

Factors identified as independently associated with stillbirth odds include factors that could be addressed through timely access to adequate antenatal care and are likely relevant throughout Australia. The identified factors should be the target of stillbirth prevention strategies/efforts. SThe stillbirth rate in Australia is a national concern. Reducing preventable stillbirths remains a global priority.

Maternal positional therapy for fetal growth and customised birth weight centile benefit in a Bayesian reanalysis of a double-blind, sham-controlled, randomised clinical trial

OBJECTIVES

To update the Ghana PrenaBelt Trial's (GPT) primary outcome data with the latest fetal growth standard and reanalyse it. To estimate the posterior probability, under various clinically relevant prior probabilities, of maternal nightly positional therapy (PT) throughout the third-trimester having a beneficial effect on customised birth weight centile (CBWC) using Bayesian analyses.

DESIGN

A reanalysis of a double-blind, sham-controlled, randomised clinical trial.

SETTING

A single, tertiary-level centre in Accra, Ghana.

PARTICIPANTS

Two-hundred participants entered, 181 completed and 167 were included in the final analysis. Participants were Ghanaian, healthy, aged 18-35 years, 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 fetal abnormalities, pregnancy complications or medical conditions complicating sleep.

INTERVENTIONS

Participants were randomised to receive treatment with either a PT or sham-PT device.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was the CBWC using the latest Perinatal Institute, Gestation-Related Optimal Weight calculator. Using Bayesian methods, posterior probabilities of achieving a greater than 0%, 5% and 10% benefit in CBWC with PT were estimated. There was no secondary outcome.

RESULTS

The median (IQR) CBWC was 42% (15-71) and 28% (9-52) in the PT and sham-PT groups, respectively (difference 8.4%; 95% CI -0.30 to 18.2; p=0.06). For achieving a >0%, >5% and >10% gain in CBWC with PT, the posterior probabilities were highly probable, probable and unlikely, respectively, given a range of prior probabilities reflecting varying degrees of pre-existing enthusiasm and scepticism.

CONCLUSIONS

Maternal nightly PT throughout the third-trimester did not have a statistically significant effect on CBWC on a frequentist analysis using the latest fetal growth standard. However, from a Bayesian analysis, clinicians can infer that PT is likely to benefit fetal growth but with a modest effect size.

TRIAL REGISTRATION NUMBER

NCT02379728.

Longitudinally assessed maternal sleep position, measures of breathing during sleep, and fetal growth in high-risk pregnancies

STUDY OBJECTIVES

Subjective recall of supine sleep during pregnancy has been linked to increased risk of stillbirth, but longitudinal, objective data are lacking. We aimed to examine how sleep position and breathing parameters change throughout pregnancy, and investigated associations between maternal supine sleep, assessed objectively in early and late gestation, and fetal growth velocity in high-risk women.

METHODS

Women with singleton pregnancies and body mass index (BMI) ≥27 kg/m2 underwent level-III sleep apnea testing. Sleep position was assessed by accelerometry. We derived percentiles of estimated fetal weight and birthweight using FetalGPSR software, then calculated growth velocity as change in percentile/week between the second-trimester anatomy scan and birth.

RESULTS

In total, 446 women were included, with N = 126 in the longitudinal sleep pattern analysis and N = 83 in the fetal growth analysis. Sleep-onset position and predominant sleep position were significantly correlated in both early (p = 0.001) and late (p < 0.01) pregnancy. However, supine going-to-bed position predicted predominant supine sleep in only 47% of women. Between early and late pregnancy there was a reduction in predominant supine sleepers (51.6% to 30.2%). Percent of sleep spent supine and oxygen desaturation index, in the third trimester, were significantly associated after BMI adjustment (B = 0.018, p = 0.04). Models did not suggest significant effects of early or late pregnancy supine sleep on growth velocity (p > 0.05).

CONCLUSIONS

Going-to-bed position predicts predominant supine sleep in less than half of women with overweight and obesity. Time spent supine throughout pregnancy correlates with measures of sleep-disordered breathing. Maternal sleep position patterns did not affect fetal growth velocity in this high-risk population, but the study was not powered to detect differences.

Mothers working to prevent early stillbirth study (MiNESS 20-28): a case-control study protocol

INTRODUCTION

In the UK, 1600 babies die every year before, during or immediately after birth at 20-28 weeks' gestation. This bereavement has a similar impact on parental physical and psychological well-being to late stillbirth (>28 weeks' gestation). Improved understanding of potentially modifiable risk factors for late stillbirth (including supine going-to-sleep position) has influenced international clinical practice. Information is now urgently required to similarly inform clinical practice and aid decision-making by expectant mothers/parents, addressing inequalities in pregnancy loss between 20 and 28 weeks.

METHODS AND ANALYSIS

This study focuses on what portion of risk of pregnancy loss 20-28 weeks' gestation is associated with exposures amenable to public health campaigns/antenatal care adaptation. A case-control study of non-anomalous singleton baby loss (via miscarriage, stillbirth or early neonatal death) 20+0 to 27+6 (n=316) and randomly selected control pregnancies (2:1 ratio; n=632) at group-matched gestations will be conducted. Data is collected via participant recall (researcher-administered questionnaire) and extraction from contemporaneous medical records. Unadjusted/confounder-adjusted ORs will be calculated. Exposures associated with early stillbirth at OR≥1.5 will be detectable (p<0.05, β>0.80) assuming exposure prevalence of 30%-60%.

ETHICS AND DISSEMINATION

NHS research ethical approval has been obtained from the London-Seasonal research ethics committee (23/LO/0622). The results will be presented at international conferences and published in peer-reviewed open-access journals. Information from this study will enable development of antenatal care and education for healthcare professionals and pregnant people to reduce risk of early stillbirth.

TRIAL REGISTRATION NUMBER

NCT06005272.

Women's perception of fetal movements and perinatal outcomes: results of a prospective cohort study

BACKGROUND

Active fetal movements (AFMs) are a sign of the well-being of the baby during pregnancy and suggests the integrity of the cardiovascular, musculoskeletal, and nervous systems of the fetus. The abnormal perception of AFMs is associated with an increased risk of adverse perinatal outcomes such as stillbirth (SB) and brain damage. Several definitions of " decreased fetal movements" have been proposed, but none of them has been universally accepted. The aim of the study is to investigate the perinatal outcomes in relation to AFMs frequency and perception in term pregnancy with an ad hoc questionnaire administered to the women before delivery.

STUDY DESIGN

This was a prospective case-control study on pregnant women at term referring to the Obstetric Unit of the University Hospital of Modena, Italy, between January 2020 and March 2020. A validated questionnaire was administered to women who agreed to participate in the study. Therefore, women were subdivided into the case and control groups: cases included women who experienced adverse perinatal outcomes (APO) such as perinatal mortality (SB and early neonatal mortality), operative delivery (cesarean section or vacuum) due to fetal distress, Apgar 5' < 7, neonatal resuscitation at birth and NICU Admission, while controls were women who experienced delivery and birth without APO in the same period.

RESULTS

Seventy-seven cases and 178 controls that compiled the questionnaire were included in the analysis. Characteristics significantly associated with APO were low education (OR 1.57, CI 95% 1.11-2.22), nulliparity (OR 1.76, CI 95% 1.20-2.58), obesity (OR 1.55, CI 95% 1.10-2.17), neonatal male gender (OR 1.92 CI95% 1.33-2.78) and centile at birth (< 10° and >90°) (OR 2.77, 95%CI 2.17, 3.55). There was no association between any answer about strengths, frequency and vigor of perceived fetal movements and APO. Even any maternal perception of fetal hiccups or uterine contractions wasn't associated with APO. On the other hand, women who referred to frequent change positions during sleep (OR 1.55 CI95% 1.05-2.30) and women who snore (OR 1.43 CI95% 1.01-2.05) showed a statistically significant increase of APO.

CONCLUSIONS

Our data confirm the significant association between modifiable risk factors (such as obesity and low education) and APO. Thus, healthcare providers should be aware of the importance of intervention in reducing obesity, therefore snoring and related sleep apnea syndrome. Finally, changing position during sleep while not the perception of modified/reduced fetal movements significantly could induce the worst obstetric outcomes.

Does fetal size affect maternal perception of fetal movements? Evidence from an individual participant data meta-analysis

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.

The effect of prone positioning on maternal haemodynamics and fetal wellbeing in the third trimester-A primary cohort study with a scoping review

INTRODUCTION

Supine sleep position is associated with stillbirth, likely secondary to inferior vena cava compression, and a reduction in cardiac output (CO) and uteroplacental perfusion. Evidence for the effects of prone position in pregnancy is less clear. This study aimed to determine the effect maternal prone position on maternal haemodynamics and fetal heart rate, compared with left lateral position.

METHODS

Twenty-one women >28 weeks' gestation underwent non-invasive CO monitoring (Cheetah) every 5 minutes and continuous fetal heart rate monitoring (MONICA) in left lateral (20 minutes), prone (30 minutes), followed by left lateral (20 minutes). Anxiety and comfort were assessed by questionnaires. Regression analyses (adjusted for time) compared variables between positions. The information derived from the primary study was used in an existing mathematical model of maternal circulation in pregnancy, to determine whether occlusion of the inferior vena cava could account for the observed effects. In addition, a scoping review was performed to identify reported clinical, haemodynamic and fetal effects of maternal prone position; studies were included if they reported clinical outcomes or effects or maternal prone position in pregnancy. Study records were grouped by publication type for ease of data synthesis and critical analysis. Meta-analysis was performed where there were sufficient studies.

RESULTS

Maternal blood pressure (BP) and total vascular resistance (TVR) were increased in prone (sBP 109 vs 104 mmHg, p = 0.03; dBP 74 vs 67 mmHg, p = 0.003; TVR 1302 vs 1075 dyne.s-1cm-5, p = 0.03). CO was reduced in prone (5.7 vs 7.1 mL/minute, p = 0.003). Fetal heart rate, variability and decelerations were unaltered. However, fetal accelerations were less common in prone position (86% vs 95%, p = 0.03). Anxiety was reduced after the procedure, compared to beforehand (p = 0.002), despite a marginal decline in comfort (p = 0.04).The model predicted that if occlusion of the inferior vena cava occurred, the sBP, dBP and CO would generally decrease. However, the TVR remained relatively consistent, which implies that the MAP and CO decrease at a similar rate when occlusion occurs. The scoping review found that maternal and fetal outcomes from 47 included case reports of prone positioning during pregnancy were generally favourable. Meta-analysis of three prospective studies investigating maternal haemodynamic effects of prone position found an increase in sBP and maternal heart rate, but no effect on respiratory rate, oxygen saturation or baseline fetal heart rate (though there was significant heterogeneity between studies).

CONCLUSION

Prone position was associated with a reduction in CO but an uncertain effect on fetal wellbeing. The decline in CO may be due to caval compression, as supported by the computational model. Further work is needed to optimise the safety of prone positioning in pregnancy.

TRIAL REGISTRATION

This trial was registered at clinicaltrials.gov (NCT04586283).

Vision-based detection and quantification of maternal sleeping position in the third trimester of pregnancy in the home setting-Building the dataset and model

In 2021, the National Guideline Alliance for the Royal College of Obstetricians and Gynaecologists reviewed the body of evidence, including two meta-analyses, implicating supine sleeping position as a risk factor for growth restriction and stillbirth. While they concluded that pregnant people should be advised to avoid going to sleep on their back after 28 weeks' gestation, their main critique of the evidence was that, to date, all studies were retrospective and sleeping position was not objectively measured. As such, the Alliance noted that it would not be possible to prospectively study the associations between sleeping position and adverse pregnancy outcomes. Our aim was to demonstrate the feasibility of building a vision-based model for automated and accurate detection and quantification of sleeping position throughout the third trimester-a model with the eventual goal to be developed further and used by researchers as a tool to enable them to either confirm or disprove the aforementioned associations. We completed a Canada-wide, cross-sectional study in 24 participants in the third trimester. Infrared videos of eleven simulated sleeping positions unique to pregnancy and a sitting position both with and without bed sheets covering the body were prospectively collected. We extracted 152,618 images from 48 videos, semi-randomly down-sampled and annotated 5,970 of them, and fed them into a deep learning algorithm, which trained and validated six models via six-fold cross-validation. The performance of the models was evaluated using an unseen testing set. The models detected the twelve positions, with and without bed sheets covering the body, achieving an average precision of 0.72 and 0.83, respectively, and an average recall ("sensitivity") of 0.67 and 0.76, respectively. For the supine class with and without bed sheets covering the body, the models achieved an average precision of 0.61 and 0.75, respectively, and an average recall of 0.74 and 0.81, respectively.

A systematic review of behaviour change techniques used in the context of stillbirth prevention

BACKGROUND

Stillbirth is one of the most devastating pregnancy outcomes that families can experience. Previous research has associated a wide range of risk factors with stillbirth, including maternal behaviours such as substance use, sleep position and attendance and engagement with antenatal care. Hence, some preventive efforts have been focused on tackling the behavioural risk factors for stillbirth. This study aimed to identify the Behaviour Change Techniques (BCTs) used in behaviour change interventions tacking behavioural risk factors for stillbirth such as substance use, sleep position, unattendance to antenatal care and weight management.

STUDY DESIGN

A systematic review of the literature was conducted in June 2021 and updated in November 2022 in five databases: CINHAL, Psyhinfo, SociIndex, PubMed and Web of Science. Studies published in high-income countries describing interventions designed in the context of stillbirth prevention, reporting stillbirth rates and changes in behaviour were eligible for inclusion. BCTs were identified using the Behaviour Change Technique Taxonomy v1.

RESULTS

Nine interventions were included in this review identified in 16 different publications. Of these, 4 interventions focused on more than one behaviour (smoking, monitoring fetal movements, sleep position, care-seeking behaviours), one focused on smoking, three on monitoring fetal movements and one on sleep position. Twenty-seven BCTs were identified across all interventions. The most commonly used was "Information about health consequences" (n = 7/9) followed by "Adding objects to the environment" (n = 6/9). One of the interventions included in this review has not been assessed for efficacy yet, of the remaining eight, three showed results in the reduction of stillbirth rates. and four interventions produced behaviour change (smoking reductions, increased knowledge, reduced supine sleeping time).

CONCLUSIONS

Our findings suggest that interventions designed to date have limited effects on the rates of stillbirth and utilise a limited number of BCTs which are mostly focused on information provision. Further research is necessary to design evidence base behaviour change interventions with a greater focus to tackle all the other factors influencing behaviour change during pregnancy (e.g.: social influence, environmental barriers).

Stillbirth: prevention and supportive bereavement care

Around half of the two million stillbirths occurring worldwide each year are preventable. This review compiles the most up-to-date evidence to inform stillbirth prevention. Many general maternal health interventions also reduce the risk of stillbirth, for example, antenatal care attendance. This review focuses on specific aspects of care: glucose metabolism, targeted aspirin prophylaxis, clotting and immune disorders, sleep positions, fetal movement monitoring, and preconception and interconception health. In the past few years, covid-19 infection during pregnancy has emerged as a risk factor for stillbirth, particularly among women who were not vaccinated. Alongside prevention, efforts to address stillbirth must include provision of high quality, supportive, and compassionate bereavement care to improve parents' wellbeing. A growing body of evidence suggests beneficial effects for parents who received supportive care and were offered choices such as mode of birth and the option to see and hold their baby. Staff need support to be able to care for parents effectively, yet, studies consistently highlight the scarcity of specific bereavement care training for healthcare providers. Action is urgently needed and is possible. Action must be taken with the evidence available now, in healthcare settings with high or low resources, to reduce stillbirths and improve training and care.

Risk factors for late preterm and term stillbirth: A secondary analysis of an individual participant data meta-analysis

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.

Prior pregnancy loss and sleep experience during subsequent pregnancy

OBJECTIVE

To describe sleep characteristics in the third trimester of pregnancy for women who had a prior pregnancy loss compared to women with no history of loss.

DESIGN

Descriptive comparison of baseline data prior to randomization for a clinical trial.

SETTING

Participants' homes.

PARTICIPANTS

Eligible women recruited from childbirth education classes during third trimester were over 18 years old, in partnered relationships, spoke English, did not work nightshift or have a diagnosed sleep disorder, and had no current complications or prior pregnancy loss (n = 140). Women with prior miscarriage or stillbirth were offered enrollment in an ancillary study (n = 20).

MEASUREMENTS

Sleep was assessed with the Pittsburgh Sleep Quality Index (PSQI) and wrist actigraphy. Other measures included relationship satisfaction, perceived stress, and depressive symptoms. For this analysis, only third trimester data prior to randomization were compared.

RESULTS

Both groups had similar actigraphy-recorded sleep duration (7.1 ± 1.1 hours) and sleep efficiency (83.7 ± 7.9%). However, the pregnancy loss group had significantly (p = .050) worse PSQI scores (7.8 ± 2.6) than controls (6.7 ± 3.1), resulting primarily from the sleep disturbance component (p = .003), specifically bad dreams (p = .030) and legs twitching/jerking (p = .071). Controlling for demographic and health factors in multivariate analyses, prior pregnancy loss was significant for sleep disturbance (p = .047), bad dreams (p = .018), and partner-reported leg twitching/jerking (p = .048).

CONCLUSIONS

Long after the acute grief of a pregnancy loss, perceived sleep quality can be problematic during the next pregnancy. Whether poor sleep quality is present prior to the pregnancy loss or reflects long-term maternal sleep characteristics require further research.

Worth the paper it's written on? A cross-sectional study of Medical Certificate of Stillbirth accuracy in the UK

BACKGROUND

The Medical Certificate of Stillbirth (MCS) records data about a baby's death after 24 weeks of gestation but before birth. Major errors that could alter interpretation of the MCS were widespread in two UK-based regional studies.

METHODS

A multicentre evaluation was conducted, examining MCS issued 1 January 2018 to 31 December 2018 in 76 UK obstetric units. A systematic case-note review of stillbirths was conducted by Obstetric and Gynaecology trainees, generating individual 'ideal MCSs' and comparing these to the actual MCS issued. Anonymized central data analysis described rates and types of error, agreement and factors associated with major errors.

RESULTS

There were 1120 MCSs suitable for assessment, with 126 additional submitted data sets unsuitable for accuracy analysis (total 1246 cases). Gestational age demonstrated 'substantial' agreement [K = 0.73 (95% CI 0.70-0.76)]. Primary cause of death (COD) showed 'fair' agreement [K = 0.26 (95% CI 0.24-0.29)]. Major errors [696/1120; 62.1% (95% CI 59.3-64.9%)] included certificates issued for fetal demise at <24 weeks' gestation [23/696; 3.3% (95% CI 2.2-4.9%)] or neonatal death [2/696; 0.3% (95% CI 0.1-1.1%)] or incorrect primary COD [667/696; 95.8% (95% CI 94.1-97.1%)]. Of 540/1246 [43.3% (95% CI 40.6-46.1%)] 'unexplained' stillbirths, only 119/540 [22.0% (95% CI 18.8-25.7%)] remained unexplained; the majority were redesignated as either fetal growth restriction [FGR: 195/540; 36.1% (95% CI 32.2-40.3%)] or placental insufficiency [184/540; 34.1% (95% CI 30.2-38.2)]. Overall, FGR [306/1246; 24.6% (95% CI 22.3-27.0%)] was the leading primary COD after review, yet only 53/306 [17.3% (95% CI 13.5-22.1%)] FGR cases were originally attributed correctly.

CONCLUSION

This study demonstrates widespread major errors in MCS completion across the UK. MCS should only be completed following structured case-note review, with particular attention on the fetal growth trajectory.

Fetal heart rate events during sleep, and the impact of sleep disordered breathing, in pregnancies complicated by preterm fetal growth restriction: An exploratory observational case-control study

OBJECTIVES

To evaluate fetal heart rate (FHR) patterns during sleep in pregnancies complicated by preterm fetal growth restriction (FGR). To determine whether co-existing sleep-disordered breathing (SDB) impacts on acute FHR events or perinatal outcome.

DESIGN

Observational case control study.

SETTING AND POPULATION

Women with preterm FGR and gestation-matched well grown controls (estimated fetal weight above the 10th percentile with normal Doppler studies); tertiary maternity hospital, Australia.

METHODS

A polysomnogram, a test used to measure sleep patterns and diagnose sleep disorders, and concurrent cardiotocography (CTG), were analysed for respiratory events and FHR changes.

MAIN OUTCOME MEASURES

Frequency of FHR events overnight in FGR cases versus controls and in those with or without SDB.

RESULTS

Twenty-nine patients with preterm FGR and 29 controls (median estimated fetal weight 1st versus 60th percentile, P < 0.001) underwent polysomnography with concurrent CTG at a mean gestation of 30.2 weeks. The median number of FHR events per night was higher among FGR cases than among controls (3.0 events, interquartile range [IQR] 1.0-4.0, versus 1.0 [IQR 0-1.0]; P < 0.001). Women with pregnancies complicated by preterm FGR were more likely than controls to be nulliparous, receive antihypertensive medications, be supine at sleep onset, and to sleep supine (32.9% of total sleep time versus 18.3%, P = 0.03). SDB was common in both FGR and control pregnancies (48% versus 38%, respectively, P = 0.55) but was generally mild and not associated with an increase in overnight FHR events or adverse perinatal outcome.

CONCLUSIONS

Acute FHR events overnight are more common in pregnancies complicated by preterm FGR than in pregnancies with normal fetal growth. Mild SDB was common in late pregnancy and well tolerated, even by fetuses with preterm FGR.

A protocol for a systematic review of behaviour change techniques used in the context of stillbirth prevention

Background: Stillbirth is a devastating pregnancy outcome that affects approximately 3.5 per 1000 births in high-income countries. Previous research has highlighted the importance of focusing prevention efforts on targeting risk factors and vulnerable groups. A wide range of risk factors has been associated with stillbirth before, including maternal behaviours such as back sleep position, smoking, alcohol intake, illicit drug use, and inadequate attendance at antenatal care. Given the modifiable nature of these risk factors, there has been an increase in the design of behaviour change interventions targeting such behaviours to reduce the risk of stillbirth. Objectives: The aim of this study is to identify all behavioural interventions with a behavioural component designed and trialled for the prevention of stillbirth in high-income countries, and to identify the behaviour change techniques (BCTs) used in such interventions using the Behaviour Change Techniques Taxonomy V1 (BCTTv1). Inclusion criteria: Interventions will be included in this review if they (1) have the objective of reducing stillbirth rates with a focus on behavioural risk factors; (2) are implemented in high-income countries; (3) target pregnant women or women of childbearing age; and (4) are published in research articles. Methods: A systematic search of the literature will be conducted. The results of the search will be screened against our inclusion criteria by two authors. The following data items will be extracted from the selected papers: general information, study characteristics, participant and intervention/approach details. The Cochrane Effective Practice and Organization of Care (EPOC) risk of bias criteria will be used to assess the methodological quality of included studies. Intervention content will be coded for BCTs as present (+) or absent (-) by two authors using the BCTTv1, discrepancies will be discussed with a third author. A narrative synthesis approach will be used to present the results of this systematic review.

A protocol for a systematic review of behaviour change techniques used in the context of stillbirth prevention

Background: Stillbirth is a devastating pregnancy outcome that affects approximately 3.5 per 1000 births in high-income countries. Previous research has highlighted the importance of focusing prevention efforts on targeting risk factors and vulnerable groups. A wide range of risk factors has been associated with stillbirth before, including maternal behaviours such as back sleep position, smoking, alcohol intake, illicit drug use, and inadequate attendance at antenatal care. Given the modifiable nature of these risk factors, there has been an increase in the design of behaviour change interventions targeting such behaviours to reduce the risk of stillbirth. Objectives: The aim of this study is to identify all behavioural interventions with a behavioural component designed and trialled for the prevention of stillbirth in high-income countries, and to identify the behaviour change techniques (BCTs) used in such interventions using the Behaviour Change Techniques Taxonomy V1 (BCTTv1). Inclusion criteria: Interventions will be included in this review if they (1) have the objective of reducing stillbirth rates with a focus on behavioural risk factors; (2) are implemented in high-income countries; (3) target pregnant women or women of childbearing age; and (4) are published in research articles. Methods: A systematic search of the literature will be conducted. The results of the search will be screened against our inclusion criteria by two authors. The following data items will be extracted from the selected papers: general information, study characteristics, participant and intervention/approach details. The Cochrane Effective Practice and Organization of Care (EPOC) risk of bias criteria will be used to assess the methodological quality of included studies. Intervention content will be coded for BCTs as present (+) or absent (-) by two authors using the BCTTv1, discrepancies will be discussed with a third author. A narrative synthesis approach will be used to present the results of this systematic review.

Polysomnographic analysis of maternal sleep position and its relationship to pregnancy complications and sleep-disordered breathing

Links between supine "going to sleep" position and stillbirth risk have led to campaigns regarding safe maternal sleep position. This study profiles the distribution of sleep positions overnight and relationships to sleep onset position during pregnancy, and the relationships between supine sleep, sleep-disordered breathing (SDB), and pregnancy outcomes. Data from three prospective cohort studies evaluating SDB in healthy and complicated pregnancies were pooled. All participants underwent one night of polysomnography in late pregnancy and birth outcome data were collected. 187 women underwent polysomnography at a median gestation of 34 weeks'. The left lateral position was preferred for falling asleep (52%) compared to supine (14%), but sleep onset position was the dominant sleep position overnight in only half (54%) of women. The median percentage of sleep time in the supine position was 24.2%; women who fell asleep supine spent more time supine overnight compared to those who began non-supine (48.0% (30.0,65.9) vs. 22.6% (5.7,32.2), p < .001). Women with growth-restricted fetuses were more likely to fall asleep supine than those with well-grown fetuses (36.6% vs. 7.5%, p < .001). Positional SDB was observed in 46% of those with an RDI ≥ 5. Sleep onset position was the dominant position overnight for half of the sample, suggesting that sleep onset position is not always a reliable indicator of body position overnight. Supine sleep was related to fetal growth restriction and birthweight at delivery, though causality cannot be inferred. It is critical that we pursue research into verifying the important relationship between supine sleep and increased stillbirth risk, and the mechanisms behind it.

A better understanding of the association between maternal perception of foetal movements and late stillbirth-findings from an individual participant data meta-analysis

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.

Supine hypotensive syndrome of pregnancy: A review of current knowledge

Since the first description of supine hypotensive syndrome in the 1950s, its potentially detrimental effects on otherwise healthy women during late pregnancy have become a persistent challenge in obstetric practice. Establishing a 15° left lateral tilt during labour and caesarean section is a fundamental principle of obstetric care, universally adopted and upheld by current guidelines and recommendations. Reassessment of the original landmark studies in the light of current physiological and anatomical knowledge questions adherence to this standard in clinical practice. The modern practice of providing vasopressor support during caesarean delivery under neuraxial anaesthesia appears to negate any potential negative effects of a maternal full supine position. Recent MRI studies provide evidence as to the cause of supine hypotension and the physiological effects of different maternal positions at term. This review highlights current data on the acute supine hypotensive syndrome in contrast to traditional knowledge and established practice.

Modification of maternal late pregnancy sleep position: a survey evaluation of a New Zealand public health campaign

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.

Australian women's perceptions and practice of sleep position in late pregnancy: An online survey

BACKGROUND

Going-to-sleep in the supine position in later pregnancy (≥28 weeks) has been identified as a risk factor for stillbirth. Internationally, public awareness campaigns have been undertaken encouraging women to sleep on their side during late pregnancy.

AIM

This study aimed to identify sleep practices, attitudes and knowledge in pregnant women, to inform an Australian safe sleeping campaign.

METHODS

A web-based survey of pregnant women ≥28 weeks' gestation conducted from November 2017 to January 2018. The survey was adapted from international sleep surveys and disseminated via pregnancy websites and social media platforms.

FINDINGS

Three hundred and fifty-two women participated. Five (1.6%) reported going to sleep in the supine position. Most (87.8%) had received information on the importance of side-sleeping in pregnancy. Information was received from a variety of sources including maternity care providers (186; 66.2%) and the internet (177; 63.0%). Women were more likely to report going to sleep on their side if they had received advice to do so (OR 2.3; 95% CI 1.0-5.1). Thirteen (10.8%) reported receiving unsafe advice, including changing their going-to-sleep position to the supine position.

DISCUSSION

This indicates high level awareness and practice of safe late-pregnancy going-to-sleep position in participants. Opportunities remain for improvement in the information provided, and understanding needs of specific groups including Aboriginal and Torres Strait Islander women.

CONCLUSION

Findings suggest Australian women understand the importance of sleeping position in late pregnancy. Inconsistencies in information provided remain and may be addressed through public awareness campaigns targeting women and their care providers.

Maternal sleep duration and neonatal birth weight: the Japan Environment and Children's Study

BACKGROUND

The adequate maternal sleep duration required for favorable obstetric outcomes is unknown. We evaluated the association between maternal sleep duration and low birth weight infants, small for gestational age infants, and macrosomia.

METHODS

Participants enrolled in the Japan Environment and Children's Study, a nationwide birth cohort study, with singleton pregnancies after 22 weeks, who gave birth between 2011 and 2014 were enrolled and categorized into five groups according to maternal sleep duration during pregnancy: < 6.0 h, 6.0-7.9 h, 8.0-8.9 h, 9.0-9.9 h, and 10.0-12.0 h. We evaluated the association between maternal sleep duration and the incidence of low birth weight infants (< 2500 g), very low birth weight infants (< 1500 g), small for gestational age infants, and macrosomia (> 4000 g), with women with maternal sleep duration of 6.0-7.9 h as the reference, using a multiple logistic regression model.

RESULTS

In total, 82,171 participants were analyzed. The adjusted odds ratios (95% confidence intervals) for low birth weight infants in women with maternal sleep duration of 9.0-9.9 h and 10.0-12.0 h and for small for gestational age infants in women with maternal sleep duration of 9.0-9.9 h were 0.90 (0.83-0.99), 0.86 (0.76-0.99), and 0.91 (0.82-0.99), respectively, before adjusting for excessive gestational weight gain. No significant association was observed between maternal sleep duration and these outcomes after adjusting for excessive gestational weight gain. Among women with appropriate gestational weight gain, the adjusted odds ratios (95% confidence intervals) for low birth weight infants and for small for gestational age infants with sleep duration of 9.0-9.9 h were 0.88 (0.80-0.97) and 0.87 (0.78-0.97), respectively.

CONCLUSIONS

Maternal sleep duration of 9.0-9.9 h was significantly associated with the decreased incidence of low birth weight infants and small for gestational age infants in pregnant women with appropriate gestational weight gain, compared with that of 6.0-7.9 h. Care providers should provide proper counseling regarding the association between maternal sleep duration and neonatal birth weight and suggest comprehensive maternal lifestyle modifications to prevent low birth weight and small for gestational age infants.

Women's sleep position during pregnancy in low- and middle-income countries: a systematic review

Background

Approximately 2.6 million babies are stillborn each year globally, of which 98% occur in low- and middle-income countries (LMICs). A 2019 individual participant data meta-analysis of 6 studies from high-income countries found that maternal supine going-to-sleep position increased the risk of stillbirth. It is not clear whether this impact would be the same in LMICs, and the normal sleep behaviour of pregnant women in LMICs is not well understood.

Objective

Determine the prevalence of different sleeping positions among pregnant women in LMICs, and what (if any) positions were associated with stillbirth using a systematic review.

Search strategy

We systematically searched the databases Medline, Embase, Emcare, CINAHL and Global Index Medicus for relevant studies, with no date or language restrictions on 4 April 2020. Reference lists of included studies were also screened.

Selection criteria

Observational studies of maternal sleep position during pregnancy in LMICs

Data collection and analysis

Recovered citations were screened and eligible studies were included for extraction. These steps were performed by two independent reviewers. Risk of bias was assessed using the Newcastle–Ottawa Scale.

Main results

A total of 3480 citations were screened but only two studies met the inclusion criteria. The studies were conducted in Ghana and India and reported on different maternal sleep positions: supine and left lateral. In Ghana, a prevalence of 9.7% for supine sleeping position amongst 220 women was found. The primary outcome could not be extracted from the Indian study as sleep position information was only reported for women who had a stillbirth (100 of the 300 participants).

Conclusion

There is limited information on maternal sleeping position in LMICs. Since sleep position may be a modifiable risk factor for stillbirth, there is a need for further research to understand the sleep practices and behaviours of pregnant women in LMICs.

PROSPERO registration: CRD42020173314

The effects of maternal position, in late gestation pregnancy, on placental blood flow and oxygenation: an MRI study

KEY POINTS

Maternal supine sleep position in late pregnancy is associated with an increased risk of stillbirth. Maternal supine position in late pregnancy reduces maternal cardiac output and uterine blood flow. Using MRI, this study shows that compared to the left lateral position, maternal supine position in late pregnancy is associated with reduced utero-placental blood flow and oxygen transfer across the placenta with an average 6.2% reduction in oxygen delivery to the fetus and an average 11% reduction in fetal umbilical venous blood flow.

ABSTRACT

Maternal sleep position in late gestation is associated with an increased risk of stillbirth, though the pathophysiological reasons for this are unclear. Studies using magnetic resonance imaging (MRI) have shown that compared with lateral positions, lying supine causes a reduction in cardiac output, reduced abdominal aortic blood flow and reduced vena caval flow which is only partially compensated for by increased flow in the azygos venous system. Using functional MRI techniques, including an acquisition termed diffusion-relaxation combined imaging of the placenta (DECIDE), which combines diffusion weighted imaging and T2 relaxometry, blood flow and oxygen transfer were estimated in the maternal, fetal and placental compartments when subjects were scanned both supine and in left lateral positions. In late gestation pregnancy, lying supine caused a 23.7% (P < 0.0001) reduction in total internal iliac arterial blood flow to the uterus. In addition, lying in the supine position caused a 6.2% (P = 0.038) reduction in oxygen movement across the placenta. The reductions in oxygen transfer to the fetus, termed delivery flux, of 11.2% (P = 0.0597) and in fetal oxygen saturation of 4.4% (P = 0.0793) did not reach statistical significance. It is concluded that even in healthy late gestation pregnancy, maternal position significantly affects oxygen transfer across the placenta and may in part provide an explanation for late stillbirth in vulnerable fetuses.

The PLANES study: a protocol for a randomised controlled feasibility study of the placental growth factor (PlGF) blood test-informed care versus standard care alone for women with a small for gestational age fetus at or after 32 + 0 weeks' gestation

Background

Stillbirth remains a major concern across the globe and in some high-resource countries, such as the UK; efforts to reduce the rate have achieved only modest reductions. One third of stillborn babies are small for gestational age (SGA), and these pregnancies are also at risk of neonatal adverse outcomes and lifelong health problems, especially when delivered preterm. Current UK clinical guidance advocates regular monitoring and early term delivery of the SGA fetus; however, the most appropriate regimen for surveillance of these babies remains unclear and often leads to increased intervention for a large number of these women. This pilot trial will determine the feasibility of a large-scale trial refining the risk of adverse pregnancy outcome in SGA pregnancies using biomarkers of placental function sFlt-1/PlGF, identifying and intervening in only those deemed at highest risk of stillbirth.

Methods

PLANES is a randomised controlled feasibility study of women with an SGA fetus that will be conducted at two tertiary care hospitals in the UK. Once identified on ultrasound, women will be randomised into two groups in a 3:1 ratio in favour of sFlt-1/PlGF ratio led management vs standard care. Women with an SGA fetus and a normal sFlt-1/PlGF ratio will have a repeat ultrasound and sFlt-1/PlGF ratio every 2 weeks with planned birth delayed until 40 weeks. In those women with an SGA fetus and an abnormal sFlt-1/PlGF ratio, we will offer birth from 37 weeks or sooner if there are other concerning features on ultrasound. Women assigned to standard care will have an sFlt-1/PlGF ratio taken, but the results will be concealed from the clinical team, and the woman’s pregnancy will be managed as per the local NHS hospital policy. This integrated mixed method study will also involve a health economic analysis and a perspective work package exploring trial feasibility through interviews and questionnaires with participants, their partners, and clinicians.

Discussion

Our aim is to determine feasibility through the assessment of our ability to recruit and retain participants to the study. Results from this pilot study will inform the design of a future large randomised controlled trial that will be adequately powered for adverse pregnancy outcome. Such a study would provide the evidence needed to guide future management of the SGA fetus.

Trial registration

ISRCTN58254381. Registered on 4 July 2019

Associations between social and behavioural factors and the risk of late stillbirth - findings from the Midland and North of England Stillbirth case-control study

OBJECTIVE

To investigate behavioural and social characteristics of women who experienced a late stillbirth compared with women with ongoing live pregnancies at similar gestation.

DESIGN

Case-control study.

SETTING

41 maternity units in the UK.

POPULATION

Women who had a stillbirth ≥28 weeks' gestation (n = 287) and women with an ongoing pregnancy at the time of interview (n = 714).

METHODS

Data were collected using an interviewer-administered questionnaire which included questions regarding women's behaviours (e.g. alcohol intake and household smoke exposure) and social characteristics (e.g. ethnicity, employment, housing). Stress was measured by the 10-item Perceived Stress Scale.

MAIN OUTCOME MEASURE

Late stillbirth.

RESULTS

Multivariable analysis adjusting for co-existing social and behavioural factors showed women living in the most deprived quintile had an increased risk of stillbirth compared with the least deprived quintile (adjusted odds ratio [aOR] 3.16; 95% CI 1.47-6.77). There was an increased risk of late stillbirth associated with unemployment (aOR 2.32; 95% CI 1.00-5.38) and women who declined to answer the question about domestic abuse (aOR 4.12; 95% CI 2.49-6.81). A greater number of antenatal visits than recommended was associated with a reduction in stillbirth (aOR 0.26; 95% CI 0.16-0.42).

CONCLUSIONS

This study demonstrates associations between late stillbirth and socio-economic deprivation, perceived stress and domestic abuse, highlighting the need for strategies to prevent stillbirth to extend beyond maternity care. Enhanced antenatal care may be able to mitigate some of the increased risk of stillbirth.

TWEETABLE ABSTRACT

Deprivation, unemployment, social stress & declining to answer about domestic abuse increase risk of #stillbirth after 28 weeks' gestation.

A decrease in cesarean sections and labor inductions among Swedish women by awareness of fetal movements with the Mindfetalness method

Background

Maternal perception of decreased fetal movements is commonly used to assess fetal well-being. However, there are different opinions on whether healthcare professionals should encourage maternal observation of fetal movements, as researchers claim that raising awareness increases unnecessary interventions, without improving perinatal health. We aimed to investigate whether cesarean sections and labor induction increase by raising women’s awareness of fetal movements through Mindfetalness. Further, we aimed to study perinatal health after implementing Mindfetalness in maternity care.

Methods

In a cluster randomized controlled trial, 67 maternity clinics were allocated to Mindfetalness or routine care. In the Mindfetalness group, midwives distributed a leaflet telling the women to focus on the character, strength and frequency of the fetal movements without counting each movement. The instruction was to do so for 15 min daily when the fetus was awake, from gestational week 28 until birth. In this sub-group analysis, we targeted women born in Sweden giving birth from 32 weeks’ gestation. We applied the intention-to-treat principle.

Results

The Mindfetalness group included 13,029 women and the Routine-care group 13,456 women. Women randomized to Mindfetalness had less cesarean sections (18.4% vs. 20.0%, RR 0.92, CI 0.87–0.97) and labor inductions (19.2% vs. 20.3%, RR 0.95, CI 0.90–0.99) compared to the women in the Routine-care group. Less babies were born small for gestational age (8.5% vs. 9.3%, RR 0.91, CI 0.85–0.99) in the Mindfetalness group. Women in the Mindfetalness group contacted healthcare due to decreased fetal movements to a higher extent than women in the Routine care group (7.8% vs. 4.3%, RR 1.79, CI 1.62–1.97). The differences remain after adjustment for potential confounders.

Conclusions

Raising awareness about fetal movements through Mindfetalness decreased the rate of cesarean sections, labor inductions and small-for-gestational age babies.

Trial registration

ClinicalTrials.gov (NCT02865759). Registered 12 August 2016, www.clinicaltrials.gov.

The effect of body position on maternal cardiovascular function during sleep and wakefulness in late pregnancy

INTRODUCTION

An association between the increased risk of late stillbirth and the maternal supine sleeping position has been recently established. The risk of stillbirth following supine sleep has been suspected to occur as a result of aortocaval compression by the gravid uterus. A number of studies conducted during wakefulness have reported compromised cardiovascular function during supine rest, as demonstrated by reductions in cardiac output, blood pressure and utero-placental blood flow. It remains unclear whether similar effects are also present during sleep, due to the presence of key sleep-specific changes in cardiovascular function.

OBJECTIVE

To investigate the changes in maternal cardiovascular function between the supine and left-lateral positions during wakefulness and non-rapid eye movement (NREM) sleep in late pregnancy.

METHODS

Twenty-nine women with a singleton pregnancy between 24.7 and 36.7 weeks' gestation participated in a single overnight sleep study. Physiological measures (blood pressure, heart rate, heart rate variability - HRV, and pulse arrival time - PAT) were measured and recorded throughout the night using standard polysomnography equipment and the Portapres Model-2 device. As the present study evaluated cardiovascular changes during natural rest and sleep in pregnancy, participants were not given explicit instructions on which position to adopt. Body position was continuously recorded using a position monitor and verified with video recording.

RESULTS

No changes in systolic, diastolic or mean arterial blood pressure were observed between the left-lateral and supine positions during wakefulness or sleep. However, heart rate was significantly higher in the supine position compared to the left during wakefulness (p= .03), with a similar trend present during sleep (p= .11). A significantly shorter PAT was measured in the supine position (compared to the left) during wakefulness (p= .01) and sleep (p= .01). No change in HRV measures was observed between the left and supine positions in either state.

CONCLUSION

Blood pressure did not appear to differ significantly between the left-lateral and supine positions during wakefulness and sleep. The lack of blood pressure differences may reflect elevated sympathetic activity during rest and sleep in the supine position (compared to the left), suggesting that some degree of compensation for aortocaval compression may still be possible during sleep.

Sleep in the Supine Position during Pregnancy Is Associated with Fetal Cerebral Redistribution

The supine sleep position in late pregnancy is a major risk factor for stillbirth, with a population attributable risk of 5.8% and one in four pregnant women reportedly sleeping in a supine position. Although the mechanisms linking the supine sleep position and late stillbirth remain unclear, there is evidence that it exacerbates pre-existing maternal sleep disordered breathing, which is another known risk factor for adverse perinatal outcomes. Given that maternal sleep position is a potentially modifiable risk factor, the aim of this study was to characterize and correlate uteroplacental and fetal hemodynamics, including cardiac function, in a cohort of women with apparently uncomplicated pregnancies with their nocturnal sleep position. This was a prospective observational cohort study at an Australian tertiary obstetric hospital. Women were asked to complete a series of questions related to their sleep position in late pregnancy after 35 weeks of completed gestation. They also underwent an ultrasound assessment where Doppler indices of various fetoplacental vessels and fetal cardiac function were measured. Regional cerebral perfusion was also assessed. Pregnancy outcome data was extracted from the electronic hospital database for analysis. A total of 274 women were included in the final analysis. Of these, 78.1% (214/274) reported no supine sleep, and 21.9% (60/274) reported going to sleep in a supine position. The middle cerebral artery, anterior cerebral artery, and vertebral artery pulsatility indices were all significantly lower in the supine sleep cohort, as was the cerebroplacental ratio. There were no significant differences in the mode or indication for delivery or in serious neonatal outcomes, including 5-min Apgar score < 7, acidosis, and neonatal intensive care unit admission between cohorts. Women in the supine cohort were more likely to have an infant with a BW > 90th centile (p = 0.04). This data demonstrates fetal brain sparing in association with the maternal supine sleep position in a low-risk population. This data contributes to the growing body of literature attempting to elucidate the etiological pathways responsible for the association of late stillbirth with the maternal supine sleep position.

Increased placental macrophages and a pro-inflammatory profile in placentas and maternal serum in infants with a decreased growth rate in the third trimester of pregnancy

PROBLEM

There is growing evidence for the role of placental inflammation in the pathophysiology of pregnancy complications including fetal growth restriction (FGR). This study aimed to characterize the inflammatory profile in the maternal circulation and the placenta of infants who were growth restricted and those that were small for gestational age (SGA).

METHOD OF STUDY

Placental villous tissue and maternal serum were obtained from pregnancies where infants were SGA at birth or who had a decreasing growth rate (≥25 centiles) across the third trimester. Immunohistochemical and histological analyses of placental samples were conducted for macrophage number, alongside vascular and cell turnover analysis. Inflammatory profile was analyzed in maternal and placental compartments via ELISAs and multiplex assays.

RESULTS

There were significantly more CD163⁺ macrophages in placentas of infants with a decreased growth rate compared to controls, but not in SGA infants (median 8.6/ nuclei vs 3.8 and 2.9, P = .008 and P = .003, respectively). Uric acid (P = .0007) and IL-8 (P = .0008) were increased in placentas, and S100A8 (P < .0002) was increased in maternal serum of infants with decreased growth rate. No changes in the maternal serum or placental lysates of SGA infants were observed.

CONCLUSION

The evidence of an altered inflammatory profile in infants with a decreasing growth rate, but not in those that were born SGA, provides further evidence that inflammation plays a role in true FGR. It remains unclear whether the increased placental macrophages occur as a direct result, or as a consequence of the pro-inflammatory environment observed in fetal growth restriction.

The effect of positioning on maternal anatomy and hemodynamics during late pregnancy

INTRODUCTION

Supine positioning during late pregnancy causes dramatic compression of maternal abdominal vasculature and is a risk factor for stillbirth. The azygos vein has been shown to provide collateral circulation in this scenario. There are many well-known anatomical differences in abdominal vasculature between the left and right sides of the body. However, the effect of left and right positioning in pregnancy has not been well studied.

MATERIALS AND METHODS

After obtaining ethics approval, 10 women with uncomplicated pregnancies between 34 and 38 weeks gestation underwent magnetic resonance imaging in the left and right lateral positions. Phase contrast images were evaluated to measure blood flow through the abdominal aorta, inferior vena cava, and azygos vein.

RESULTS

No significant differences between left and right lateral positions were found in blood flow through the IVC at its formation (mean difference -0.15 L/min [CI -0.47, 0.18], p = .34) or through the azygos vein (mean difference 0.02 L/min [CI -0.22, 0.26], p = .87). Blood flow through the IVC just above the level of the renal veins was found to be reduced by 35% in the right lateral position when compared to the left (mean difference 1.01 L/min [CI 0.25, 1.43], p = .03). There were no significant differences in cardiac output or blood flow through the abdominal aorta.

CONCLUSIONS

While it was noted that blood flow through the IVC immediately above the level of the renal veins was reduced in the right lateral position, this did not appear to impact significantly on maternal cardiac output or blood flow through the azygos vein.

Parents' Experiences About Support Following Stillbirth and Neonatal Death

BACKGROUND

Stillbirth and neonatal death are one of the most stressful life events, with negative outcomes for parents. Society does not recognize this type of loss, and parental grieving is particularly complicated and intense.

PURPOSE

The aim of this study was to describe and understand the experiences of parents in relation to professional and social support following stillbirth and neonatal death.

METHODS

This was a qualitative study based on Gadamer's hermeneutic phenomenology. Twenty-one semistructured interviews were carried out. Inductive analysis was used to find themes based on the data.

RESULTS

Twenty-one parents (13 mothers and 8 fathers) from 6 families participated in the study. The analysis identified 2 main themes: (1) "professional care in dealing with parents' grief," with the subthemes "important aspects of professional care," "continuing of pathways of care"; and (2) "effects of social support in parental grief," including the subthemes "the silence that surrounds grieving parents," "family and other children: a key element," and "perinatal loss support groups: a reciprocal help."

IMPLICATIONS FOR PRACTICE

Counseling and support according to parents' requirements by an interdisciplinary team of professionals educated in perinatal loss and ethical family-centered care is needed. A social support system for families is necessary to avoid negative emotional consequences.

IMPLICATIONS FOR RESEARCH

Further research is needed to analyze midwives' and nurses' experience as facilitators to improve parental grief and the difficulties experienced by the family, other children, and friends of parents with perinatal loss in providing support.

Associations between symptoms of sleep-disordered breathing and maternal sleep patterns with late stillbirth: Findings from an individual participant data meta-analysis

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.

Racial/ethnic disparities in sleep duration and sleep disturbances among pregnant and non-pregnant women in the United States

Sleep disturbances among pregnant women are increasingly linked to suboptimal maternal/birth outcomes. Few studies in the USA investigating sleep by pregnancy status have included racially/ethnically diverse populations, despite worsening disparities in adverse birth outcomes. Using a nationally representative sample of 71,644 (2,349 pregnant) women from the National Health Interview Survey (2004-2017), we investigated relationships between self-reported pregnancy and six sleep characteristics stratified by race/ethnicity. We also examined associations between race/ethnicity and sleep stratified by pregnancy status. We used average marginal predictions from fitted logistic regression models to estimate prevalence ratios (PRs) and 95% confidence intervals (CIs) for each sleep dimension, adjusting for sociodemographic and health characteristics. Pregnant women were less likely than non-pregnant women to report short sleep (PR_Overall  = 0.75; 95% CI, 0.68-0.82) and more likely to report long sleep (PR_Overall  = 2.06; 95% CI, 1.74-2.43) and trouble staying asleep (PR_Overall  = 1.34; 95% CI, 1.25-1.44). The association between pregnancy and sleep duration was less pronounced among women aged 35-49 years compared to those <35 years. Among white women, sleep medication use was less prevalent among pregnant compared to non-pregnant women (PR_White  = 0.45; 95% CI, 0.31-0.64), but this association was not observed among black women (PR_Black  = 0.98; 95% CI, 0.46-2.09) and was less pronounced among Hispanic/Latina women (PR_{Hispanic/Latina}  = 0.82; 95% CI, 0.38-1.77). Compared to pregnant white women, pregnant black women had a higher short sleep prevalence (PR_Black  = 1.35; 95% CI, 1.08-1.67). Given disparities in maternal/birth outcomes and sleep, expectant mothers (particularly racial/ethnic minorities) may need screening followed by treatment for sleep disturbances. Our findings should be interpreted in the historical and sociocultural context of the USA.

'InUTERO': The effectiveness of an educational half day stillbirth awareness workshop for maternity care providers

BACKGROUND

There is a disconnect between what maternity care providers consider should be done and what they actually do with respect to talking with their pregnant clients about reducing their risk of stillbirth. This suggests that they would benefit from receiving up-to-date knowledge about stillbirth, alongside education that provides them with strategies for talking about stillbirth with pregnant women.

OBJECTIVES

To gain an understanding of maternity care provider (obstetricians and midwives) knowledge of stillbirth and determine whether delivering a half day workshop improves knowledge and results in intention to change practice.

DESIGN

A pre-post intervention study.

SETTING

Maternity care providers (Obstetricians, Midwives) working in the northern areas of Tasmania, Australia were asked, via questionnaire, about their knowledge of stillbirth both before and after attending a half-day workshop.

PARTICIPANTS

Maternity care providers (n = 51) attended the workshop and 30 (59%) completed both the pre-workshop and post-workshop surveys.

METHODS

A four hour interactive workshop grounded in understanding the stillbirth experience. Participants were given up-to-date information about stillbirth risks and current prevention research as well as provided with an actionable step wise approach to talking about stillbirth prevention in pregnancy.

RESULTS

Stillbirth knowledge scores (total of 8-points) significantly increased following the workshop (pre: mean = 2.9 ± 1.5; post: mean = 4.7 ± 1.4 points, t ₂₉ = 7.9, <0.001). Before the workshop, only 20% of participants responded that they "always" or usually" discussed the possibility stillbirth occurring with pregnant women in their care whereas, after the workshop, nearly all (88%) indicated that they planned to "always" discuss stillbirth with their pregnant clients.

CONCLUSIONS

Attending a stillbirth awareness for prevention education workshop resulted in significant knowledge improvement and self-reported intention to change practice in a group of Australian maternity care providers. While these results are promising, further study is needed to determine the presence and extent of actual practice change following such education.

Effects of maternal sleep position on fetal and maternal heart rate patterns using overnight home fetal ECG recordings

OBJECTIVE

To assess the effects of maternal position on maternal and fetal heart rate and heart rate variability (HRV) in healthy late gestation pregnancies using non-invasive techniques during overnight studies.

METHODS

In an observational study of women between 34 and 36 weeks of pregnancy conducted from September 1, 2013, to March 31, 2014, at Columbia University Medical Center, New York, US, maternal and fetal ECG recordings and position monitoring were undertaken through the night in the woman's own home. These data were used for time domain analyses of fetal and maternal heart rate and HRV.

RESULTS

Forty-two women were recruited to the study which showed that maternal position affected maternal heart rate (MHR), with left side sleeping associated with lower heart rate (left vs right P=0.017, left vs supine P=0.027) and higher overall HRV (left vs right P=0.032). MHR showed significant overnight changes (P=0.032). No significant positional or overnight effects were observed in fetal heart rate patterns.

CONCLUSION

This study uniquely incorporated analyses on maternal and fetal physiology and extended the knowledge of effects of maternal overnight sleep position on MHR in the natural sleep environment.

Hemodynamic changes in women with symptoms of supine hypotensive syndrome

INTRODUCTION

Supine positioning during late pregnancy causes the gravid uterus to compress the inferior vena cava, resulting in dramatic hemodynamic changes. The maintenance of placental perfusion requires maternal circulatory and autonomic adaptations. Women with supine hypotensive syndrome (defined as a drop in systolic blood pressure of anything between 15 and 30 mmHg or an increase in heart rate of 20 bpm, with or without symptoms) may have reduced ability to compensate for the effects of supine positioning.

MATERIAL AND METHODS

Twelve women with uncomplicated pregnancies and no symptoms of supine hypotension (normal) and 10 women with uncomplicated pregnancies who reported symptoms of supine hypotension between 34 and 38 weeks' gestation underwent magnetic resonance imaging in the supine and left lateral positions. Phase contrast images were evaluated to measure blood flow through the aorta, inferior vena cava, superior vena cava and azygos vein.

RESULTS

Women with symptoms of supine hypotension showed significant reductions in azygos venous flow rate compared with the normal group (-0.15 (-0.30 to -0.01) L/min). Those with symptoms showed no statistically significant compensatory changes in heart rate compared with the normal group (heart rate change 4.5 (-3.1 to 12.1) bpm). Hemodynamic changes in response to positioning were similar across both groups including: a reduction in inferior vena cava blood flow, reduction in cardiac output and an increase in azygos blood flow.

CONCLUSIONS

Maternal hemodynamic adaptations were found to be consistent across groups irrespective of whether the women had symptoms of supine hypotension. In both groups a reduction in blood flow through the inferior vena cava occurred in the supine position with a subsequent reduction in cardiac output. Both groups showed a compensatory increase in blood flow through the azygos vein in order to partially compensate for this. Taking into account the effect of maternal position, women with symptoms were found to have reduced azygos flow compared with asymptomatic women. There was a significant increase in heart rate when the women were supine than when they were in the left lateral position.

Polysomnographic features of pregnancy: A systematic review

Symptoms of sleep disturbances are common among pregnant women and generally worsen across gestation. Pregnancy-related sleep disorders are not only associated with a poor quality of life of the affected mothers, but also with adverse perinatal outcomes, including perinatal depression, gestational diabetes, preeclampsia, and preterm birth. The current knowledge about the impact of sleep disorders during pregnancy largely derives from the results of sleep surveys conducted in various populations. However, the number of studies examining changes in objective sleep variables during pregnancy via polysomnography has progressively increased in recent years. Here we systematically reviewed the polysomnographic studies available in the literature with the aim to describe the sleep pattern and to identify possible markers of sleep disruption in pregnant women. Based on our analysis, subjective worsening of sleep quality across gestation is related to objective changes in sleep macrostructure, which become particularly evident in the third trimester. Pregnancy per se does not represent an independent risk factor for developing major polysomnography-assessed sleep disorders in otherwise healthy women. However, in women presenting predisposing factors, such as obesity or hypertension, physiological changes occurring during pregnancy may contribute to the onset of pathological conditions, especially sleep-disordered breathing, which must be carefully considered.

Association of Supine Going-to-Sleep Position in Late Pregnancy With Reduced Birth Weight: A Secondary Analysis of an Individual Participant Data Meta-analysis

IMPORTANCE

Supine maternal position in the third trimester is associated with reduced uterine blood flow and increased risk of late stillbirth. As reduced uterine blood flow is also associated with fetal growth restriction, this study explored the association between the position in which pregnant women went to sleep and infant birth weight.

OBJECTIVE

To examine the association between supine position when going to sleep in women after 28 weeks of pregnancy and lower birth weight and birth weight centiles.

DESIGN, SETTING, AND PARTICIPANTS

Prespecified subgroup analysis using data from controls in an individual participant data meta-analysis of 4 case-control studies investigating sleep and stillbirth in New Zealand, Australia, and the United Kingdom. Participants were women with ongoing pregnancies at 28 weeks' gestation or more at interview.

MAIN OUTCOMES AND MEASURES

The primary outcome was adjusted mean difference (aMD) in birth weight. Secondary outcomes were birth weight centiles (INTERGROWTH-21st and customized) and adjusted odds ratios (aORs) for birth weight less than 50th and less than 10th centile (small for gestational age) for supine vs nonsupine going-to-sleep position in the last 1 to 4 weeks, adjusted for variables known to be associated with birth size.

RESULTS

Of 1760 women (mean [SD] age, 30.25 [5.46] years), 57 (3.2%) reported they usually went to sleep supine during the previous 1 to 4 weeks. Adjusted mean (SE) birth weight was 3410 (112) g among women who reported supine position and 3554 (98) g among women who reported nonsupine position (aMD, 144 g; 95% CI, -253 to -36 g; P = .009), representing an approximate 10-percentile reduction in adjusted mean INTERGROWTH-21st (48.5 vs 58.6; aMD, -10.1; 95% CI, -17.1 to -3.1) and customized (40.7 vs 49.7; aMD, -9.0; 95% CI, -16.6 to -1.4) centiles. There was a nonsignificant increase in birth weight at less than the 50th INTERGROWTH-21st centile (aOR, 1.90; 95% CI, 0.83-4.34) and a 2-fold increase in birth weight at less than the 50th customized centile (aOR, 2.12; 95% CI, 1.20-3.76). Going to sleep supine was associated with a 3-fold increase in small for gestational age birth weight by INTERGROWTH-21st standards (aOR, 3.23; 95% CI, 1.37-7.59) and a nonsignificant increase in small for gestational age birth weight customized standards (aOR, 1.63; 95% CI, 0.77-3.44).

CONCLUSIONS AND RELEVANCE

This study found that going to sleep in a supine position in late pregnancy was independently associated with reduced birth weight and birth weight centile. This novel association is biologically plausible and likely modifiable. Public health campaigns that encourage women in the third trimester of pregnancy to settle to sleep on their side have potential to optimize birth weight.

Prospective Evaluation of Maternal Sleep Position Through 30 Weeks of Gestation and Adverse Pregnancy Outcomes

OBJECTIVE

To examine the relationship between prospectively assessed maternal sleep position and subsequent adverse pregnancy outcomes.

METHODS

This was a secondary analysis of a prospective observational multicenter cohort study of nulliparous women with singleton gestations who were enrolled between October 2010 and May 2014. Participants had three study visits that were not part of clinical care. They prospectively completed in-depth sleep questionnaires between 6 0/7 and 13 6/7 weeks of gestation and 22 0/7 and 29 6/7 weeks of gestation, the first and third study visits. A subset of women also underwent level 3 home sleep tests using the Embletta Gold device. The primary outcome was a composite of adverse pregnancy outcomes such as stillbirth, a small-for-gestational-age newborn, and gestational hypertensive disorders.

RESULTS

A total of 8,706 (of 10,038) women had data from at least one sleep questionnaire and for pregnancy outcomes, and they comprised the population for this analysis. The primary outcome occurred in 1,903 pregnancies (22%). There was no association between reported non-left lateral or supine sleep during the last week of the first visit (adjusted odds ratio [aOR] 1.00 [95% CI 0.89-1.14]) or third visit (aOR 0.99 [95% CI 0.89-1.11] and the composite or any individual outcome, except for an apparent protective effect for stillbirth at the third visit (aOR 0.27 (95% CI 0.09-0.75). Women with objectively measured supine sleep position for at least 50% of the time were no more likely than those in the supine position 50% or less of the time to have the composite adverse outcome.

CONCLUSIONS

Going to sleep in the supine or right lateral position, as self-reported before the development of pregnancy outcome and objectively assessed through 30 weeks of gestation, was not associated with an increased risk of stillbirth, a small-for-gestational-age newborn, or gestational hypertensive disorders.

Modifiable risk factors for stillbirth: a literature review

A stillbirth is defined as an infant born weighing 500 g and/or more or at a gestational age of 24 weeks who shows no signs of life. Having a stillborn baby has a wide range of consequences that can affect parents, family and the healthcare professionals involved. Several risk factors have been associated with an increased risk of stillbirth: including maternal medical factors, maternal characteristics, fetal factors, sociodemographic factors and behavioral factors. The aim of this work is to review the literature on risk factors that have a behavioral component. The main behaviors modulating the risk of stillbirth that have been more widely studied in the literature include use of substances (smoking, alcohol, illicit drugs and medical drugs), weight management, attendance at antenatal care and sleeping position. There is evidence in the literature that supports that all those behaviors have an impact on the risk of stillbirth, especially in the cases of smoking and drugs consumption during the pregnancy. Hence, more research is needed to establish interventions targeting these behaviors as preventive measures to reduce the risk of adverse obstetric outcomes.

Inequalities and stillbirth in the UK: a meta-narrative review

OBJECTIVE

To review what is known about the relationship between stillbirth and inequalities from different disciplinary perspectives to inform stillbirth prevention strategies.

DESIGN

Systematic review using the meta-narrative method.

SETTING

Studies undertaken in the UK.

DATA SOURCES

Scoping phase: experts in field, exploratory electronic searches and handsearching. Systematic searches phase: Nine databases with no geographical or date restrictions. Non-English language studies were excluded.

STUDY SELECTION

Any investigation of stillbirth and inequalities with a UK component.

DATA EXTRACTION AND SYNTHESIS

Three authors extracted data and assessed study quality. Data were summarised, tabulated and presented graphically before synthesis of the unfolding storyline by research tradition; and then of the commonalities, differences and interplays between narratives into resultant summary meta-themes.

RESULTS

Fifty-four sources from nine distinctive research traditions were included. The evidence of associations between social inequalities and stillbirth spanned 70 years. Across research traditions, there was recurrent evidence of the social gradient remaining constant or increasing, fuelling repeated calls for action (meta-theme 1: something must be done). There was less evidence of an effective response to these calls. Data pertaining to socioeconomic, area and ethnic disparities were routinely collected, but not consistently recorded, monitored or reported in relation to stillbirth (meta-theme 2: problems of precision). Many studies stressed the interplay of socioeconomic status, deprivation or ethnicity with aggregated factors including heritable, structural, environmental and lifestyle factors (meta-theme 3: moving from associations towards intersectionality and intervention(s)). No intervention studies were identified.

CONCLUSION

Research investigating inequalities and stillbirth in the UK is underdeveloped. This is despite repeated evidence of an association between stillbirth risk and poverty, and stillbirth risk, poverty and ethnicity. A specific research forum is required to lead the development of research and policy in this area, which can harness the multiple relevant research perspectives and address the intersections between different policy areas.

PROSPERO REGISTRATION NUMBER

CRD42017079228.

Exploring associations of maternal sleep during periconceptional period with congenital heart disease in offspring

Background

In general, the existing evidence points to a role for maternal sleep in pregnancy complications and fetal growth, however, little has been focused on birth defects. We aimed to explore the association between periconceptional poor sleep and the risk of congenital heart disease (CHD), and to examine if daytime napping could to some extent change the association.

Methods

A case–control study was conducted in Shanghai Children's Medical Center, in which, a total of 524 cases (262 simple CHD vs. 262 severe CHD), along with 262 controls.

Results

In the multivariable logistic analysis, poor sleep could increase the risk of both simple CHD (OR = 2.486, 95% CI = 1.619–3.818) and severe CHD (OR = 1.950, 95% CI = 1.269–2.997), while routine daytime nap could decrease risk of simple CHD (OR = 0.634, 95% CI = 0.435–0.923). In the stratified analysis, the concurrence with routine daytime nap could weaken the risk of simple CHD caused by poor sleep (OR = 3.183, 95% CI: 1.830–5.537 decreased to OR = 2.236, 95% CI: 1.200–4.165). The examinations were repeated in ventricular septal defect and tetralogy of Fallot, and the established associations can be verified. Moreover, all these findings were also similarly observed in both propensity‐score‐adjusted and propensity‐score‐matched analyses.

Conclusions

Poor maternal sleep around periconceptional period seems to be an independent risk factor for CHD. The concurrence with daytime nap could to some extent reduce the risk in simple CHD. The results individually and collectively put forward the importance of maternal sleep in embryonic heart development.