Number of live births and fetal deaths (stillbirths), by type of birth (single or multiple), 1991 to most recent year.

BackgroundPrevious studies have demonstrated an increased risk of cardiovascular disease (CVD) in women with a history of pregnancy loss. Less is known about whether pregnancy loss is associated with age at the onset of CVD, but this is a question of interest, as a demonstrated association of pregnancy loss with early-onset CVD may provide clues to the biological basis of the association, as well as having implications for clinical care. We conducted an age-stratified analysis of pregnancy loss history and incident CVD in a large cohort of postmenopausal women aged 50–79 years old.MethodsAssociations between a history of pregnancy loss and incident CVD were examined among participants in the Women's Health Initiative Observational Study. Exposures were any history of pregnancy loss (miscarriage and/or stillbirth), recurrent (2+) loss, and a history of stillbirth. Logistic regression analyses were used to examine associations between pregnancy loss and incident CVD within 5 years of study entry in three age strata (50–59, 69–69, and 70–79). Outcomes of interest were total CVD, coronary heart disease (CHD), congestive heart failure, and stroke. To assess the risk of early onset CVD, Cox proportional hazard regression was used to examine incident CVD before the age of 60 in a subset of subjects aged 50–59 at study entry.ResultsAfter adjustment for cardiovascular risk factors, a history of stillbirth was associated with an elevated risk of all cardiovascular outcomes in the study cohort within 5 years of study entry. Interactions between age and pregnancy loss exposures were not significant for any cardiovascular outcome; however, age-stratified analyses demonstrated an association between a history of stillbirth and risk of incident CVD within 5 years in all age groups, with the highest point estimate seen in women aged 50–59 (OR 1.99; 95% CI, 1.16–3.43). Additionally, stillbirth was associated with incident CHD among women aged 50–59 (OR 3.12; 95% CI, 1.33–7.29) and 60–69 (OR 2.06; 95% CI, 1.24–3.43) and with incident heart failure and stroke among women aged 70–79. Among women aged 50–59 with a history of stillbirth, a non-significantly elevated hazard ratio was observed for heart failure before the age of 60 (HR 2.93, 95% CI, 0.96–6.64).ConclusionsHistory of stillbirth was strongly associated with a risk of cardiovascular outcomes within 5 years of baseline in a cohort of postmenopausal women aged 50–79. History of pregnancy loss, and of stillbirth in particular, might be a clinically useful marker of cardiovascular disease risk in women.

The number of babies born with no sign of life at 28 weeks or more of gestation, per 1,000 total births. The data includes a range of values from 2000 to 2019 for the toal number of babies born. This data is sourced from the UN Inter-Agency Group for Child Mortality Estimation. When calculating the stillbirth rate, the UN IGME uses a model to identify global and national trends and compare between countries. In cases where counts of stillbirths and live births are available, the stillbirth rate is calculated as the number of stillbirths divided by the sum of the number of live births and number of stillbirths. For household surveys, stillbirth data are obtained from full pregnancy histories (PH) or reproductive calendars (RC). In the PH, women are asked to provide information on the duration of all lifetime pregnancies, the outcome of the pregnancy (e.g. miscarriage, stillbirth or live birth) and the date of birth or end of pregnancy. In the RC, women are asked about the duration and month of pregnancy end for pregnancies that did not end in a live birth in the last 60 months.The estimates are based on high quality nationally representative data including statistics from civil registration systems, medical birth and death registries, results from household surveys, population studies and censuses.The stillbirth rate estimates are produced in conjunction with national level agencies such as a country’s Ministry of Health, National Statistics Office, or other relevant agencies.

There are approximately 5 million pregnancies per year in the United States, with 1 million ending in miscarriage (a loss occurring prior to 20 weeks of gestation) and over 20,000 ending in stillbirth at or beyond 20 weeks of gestation. As many as 50% of these losses are unexplained. Our objective was to evaluate the efficacy of expanding the placental pathology diagnostic categories to include the explicit categories of 1) dysmorphic chorionic villi and 2) small placenta to decrease the unexplained fraction. Using a clinical database of 1,256 previously unexplained losses at 6–43 weeks of gestation, the most prevalent abnormality associated with each loss was determined through examination of its placental pathology slides. Of 1,256 cases analyzed from 922 patients, there were 878 (69.9%) miscarriages and 378 (30.1%) antepartum stillbirths. We determined the pathologic diagnoses for 1,150/1,256 (91.6%) of the entire series, 777/878 (88.5%) of the miscarriages (<20 weeks’ gestation),...

BackgroundPrevious studies have demonstrated an increased risk of cardiovascular disease (CVD) in women with a history of pregnancy loss. Less is known about whether pregnancy loss is associated with age at the onset of CVD, but this is a question of interest, as a demonstrated association of pregnancy loss with early-onset CVD may provide clues to the biological basis of the association, as well as having implications for clinical care. We conducted an age-stratified analysis of pregnancy loss history and incident CVD in a large cohort of postmenopausal women aged 50–79 years old.MethodsAssociations between a history of pregnancy loss and incident CVD were examined among participants in the Women's Health Initiative Observational Study. Exposures were any history of pregnancy loss (miscarriage and/or stillbirth), recurrent (2+) loss, and a history of stillbirth. Logistic regression analyses were used to examine associations between pregnancy loss and incident CVD within 5 years of study entry in three age strata (50–59, 69–69, and 70–79). Outcomes of interest were total CVD, coronary heart disease (CHD), congestive heart failure, and stroke. To assess the risk of early onset CVD, Cox proportional hazard regression was used to examine incident CVD before the age of 60 in a subset of subjects aged 50–59 at study entry.ResultsAfter adjustment for cardiovascular risk factors, a history of stillbirth was associated with an elevated risk of all cardiovascular outcomes in the study cohort within 5 years of study entry. Interactions between age and pregnancy loss exposures were not significant for any cardiovascular outcome; however, age-stratified analyses demonstrated an association between a history of stillbirth and risk of incident CVD within 5 years in all age groups, with the highest point estimate seen in women aged 50–59 (OR 1.99; 95% CI, 1.16–3.43). Additionally, stillbirth was associated with incident CHD among women aged 50–59 (OR 3.12; 95% CI, 1.33–7.29) and 60–69 (OR 2.06; 95% CI, 1.24–3.43) and with incident heart failure and stroke among women aged 70–79. Among women aged 50–59 with a history of stillbirth, a non-significantly elevated hazard ratio was observed for heart failure before the age of 60 (HR 2.93, 95% CI, 0.96–6.64).ConclusionsHistory of stillbirth was strongly associated with a risk of cardiovascular outcomes within 5 years of baseline in a cohort of postmenopausal women aged 50–79. History of pregnancy loss, and of stillbirth in particular, might be a clinically useful marker of cardiovascular disease risk in women.

This data is part of a prospective antenatal and birth cohort and database established in 1986 by SMRU. The current files are in SPSS. The data is labelled in the file and the .sps file explains the data presented in the manuscript. The data is still under primary analysis by the creators but this selected portion will be made publicly available. Introduction The WHO definition of stillbirth uses 28 weeks’ gestation as the cut-point, but also defines extreme preterm birth as 24 to <28 weeks’ gestation. This presents a problem with the gestational limit of miscarriage, and hence reporting of stillbirth, preterm birth and neonatal death. The objective of this study is to provide a synopsis of the outcome of a population cohort of pregnancies on the Thailand-Myanmar border between 24 to <28 weeks’ gestation. Methods Records from the Shoklo Malaria Research Unit Antenatal Clinic were reviewed for pregnancy outcomes in the gestational window of 24 to <28 weeks, and each record, including ultrasounds reports, were reviewed to clarify the pregnancy outcome. Pregnancies where there was evidence of fetal demise prior to 24 weeks were classified as miscarriage; those viable at 24 weeks’ gestation and born before 28 weeks were coded as births, and further subdivided into live- and stillbirth. Results Between 1995 and 2015, in a cohort of 49,931 women, 0.6% (318) of outcomes occurred from 24 to <28 weeks’ gestation, and 35.8% (114) were miscarriages, with confirmatory ultrasound of fetal demise in 45.4% (49/108). Of pregnancies not ending in miscarriage, 37.7% (77/204) were stillborn and of those born alive, neonatal mortality was 98.3% (115/117). One infant survived past the first year of life. Congenital abnormality rate was 12.0% (23/191). Ultrasound was associated with a greater proportion of pregnancy outcome being coded as delivery. Conclusion In this limited-resource setting, pregnancy outcome from 24 to <28 weeks’ gestation included: 0.6% of all outcomes, of which one-third were miscarriages, one-third of births were stillborn and mortality of livebirths approached 100%. In the scale-up to preventable newborns deaths, at least initially, greater benefits will be obtained by focusing on the greater number of viable newborns with a gestation of 28 weeks or more. KEYWORDS: extreme preterm birth, limited-resource, low-income, marginalized, miscarriage, neonatal death, stillbirth, ultrasound

Objective

Trophoblast inclusions—cross sections of abnormal trophoblast bilayer infoldings— have previously been associated with aneuploidy, placenta accreta, and prematurity. This study was conducted to establish the relationship between trophoblast inclusions and a range of placental, pregnancy, and birth outcomes in a patient population with high smoking and alcohol exposure. Specifically, we sought to evaluate the association between the presence of trophoblast inclusions and 1) three primary birth outcomes: full-term birth, preterm birth, and stillbirth; 2) gestational age at delivery; and 3) specific placental pathologies.

Methods

Two slides containing chorionic villi were evaluated from 589 placentas that were collected from Stellenbosch University in Cape Town, South Africa as part of the prospective, multicenter cohort Safe Passage Study of the Prenatal Alcohol and SIDS and Stillbirth Network. The subsample included 307 full-term live births, 212 preterm live births, and 70 stillbirths.

Results

We found that the odds of identifying at least one trophoblast inclusion across two slides of chorionic villi was significantly higher for placentas from preterm compared to term liveborn deliveries (OR = 1.74; 95% CI: 1.22, 2.49, p = 0.002), with an even greater odds ratio for placentas from stillborn compared to term liveborn deliveries (OR = 4.95; 95% CI: 2.78, 8.80, p < 0.001). Gestational age at delivery was inversely associated with trophoblast inclusion frequency. Trophoblast inclusions were significantly associated with small for gestational age birthweight, induction of labor, villous edema, placental infarction, and inflammation of the chorionic plate.

Conclusions

The novel associations that we report warrant further investigation in order to understand the complex network of biological mechanisms through which the factors that lead to trophoblast inclusions may influence or reflect the trajectory and health of a pregnancy. Ultimately, this line of research may provide critical insights that could inform both clinical and research applications.

This dataset is about book series. It has 1 row and is filtered where the books is When your baby dies through miscarriage or stillbirth. It features 10 columns including number of authors, number of books, earliest publication date, and latest publication date.

These data are from a cohort of over 4000 pregnant women in Mchinji District, Malawi, who were followed up after the end of their pregnancy. The women were asked the London Measure of Unplanned Pregnancy (LMUP), as well as obstetric history and socio-demographic information. They were followed up after the end of the neonatal period to assess pregnancy outcome and maternal mental health status.

BackgroundIncreasing evidence suggests that pregnancy loss can lead to negative emotional outcomes, such as anxiety and depression, for women. However, limited knowledge exists regarding the long-term risk of mental disorders among individuals who have experienced pregnancy loss.ObjectiveTo investigate the associations between pregnancy loss and the risk of common mental disorders.MethodsIn the UK Biobank, a total of 218,990 women without any mental disorder at baseline were enrolled between 2006 and 2010 and followed until October 2022. Information on the history of pregnancy loss was obtained through self-reported questionnaires at baseline. Cox proportional hazard regression models were used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for associations between pregnancy loss and common mental disorders.ResultsDuring a median follow-up time of 13.36 years, there were 26,930 incident cases of common mental disorders. Incidence rates of common mental disorders were elevated among women with a history of stillbirth (HR 1.15, 95% CI: 1.07–1.23), miscarriage (HR 1.06, 95% CI: 1.02–1.10), or pregnancy termination (HR 1.21, 95% CI: 1.17–1.25) compared to those without such experiences. Furthermore, the risk of common mental disorders significantly increased in women with two or more miscarriages (HR 1.14, 95% CI: 1.08–1.19) or two or more pregnancy terminations (HR 1.39, 95% CI: 1.30–1.48).ConclusionsPregnancy loss is associated with an increased risk of common mental disorders in women later in life. These findings may contribute to the enhancement of long-term monitoring and prevention of common mental disorders for women with such a history.

Anonymised transcripts of interviews with (1) professionals working in the funerary industry (funeral directors, bereavement service managers, and officers at national funeral care institutions), (2) bereavement care providers in hospitals within NHS England, (3) support workers at the Stillbirth and Neonatal Death Charity (Sands), Antenatal Results and Choices (ARC) and the Miscarriage Association (MA), (4) people (and partners of people) who have experienced a miscarriage, a stillbirth, or termination due to fetal anomaly. We also conducted focus group meetings with people (and partners of people) who have experienced a miscarriage, a stillbirth, or a termination due to fetal anomaly.

We propose a socio-legal, linguistic study of how people in England who have experienced miscarriage, termination, and stillbirth reach decisions concerning the disposal of the remains of pregnancy, how their perceptions of the law impact on their decision-making, and how they communicate their experiences and choices to those who are there to support them. The project engages with an important and large-scale social issue: it is estimated that approximately 1 in 5 known pregnancies end in miscarriage, 1 in every 200 births is a stillbirth, and 2,000 terminations for reasons of fetal anomaly are performed in the UK each year. The study seeks to replace the social and legal uncertainty surrounding the question of what to do with the remains of pregnancy by engaging stakeholders with a view to producing evidence-led policy and practice.

English law is not straightforward when it comes to definitions about the remains of pregnancy: in legal terms, the remains occupy a mid-way category somewhere between person and human tissue. Not surprisingly, those affected often lack knowledge of the legal options for the disposal of the remains. The disposal of the remains of pregnancy has been the subject of increased levels of media controversy and public scrutiny in the last 12 months. In the wake of these scandals, and in recognition of the need for national guidance in this area, the Human Tissue Authority (HTA) recently published guidelines for the disposal of the remains of pregnancy (25 March 2015). A key aspect of our investigation will assess how these guidelines are interpreted in practice by professionals (such as midwives and funeral directors) and how this shapes the way in which options are presented to the bereaved. We will also examine whether the guidelines take sufficient account of the views, experiences and needs of the bereaved. Our findings will inform the HTA's revision of the guidelines, and in doing so, we aim to contribute to improved care pathways for those experiencing pregnancy loss. The end of a pregnancy may be felt as a form of bereavement, one that usually involves complex emotions that are difficult to articulate. Linguistics research has demonstrated that metaphor is prevalent in the language used when people are communicating about emotionally charged, life-changing experiences. Furthermore, when people face bereavement through miscarriage, termination, and stillbirth, it can be difficult to organise a 'conventional' funeral, so people create their own, drawing on a selection of metaphors. This project will accordingly pay careful attention not just to what the bereaved and those who support them say, but how they express themselves through words and actions. In particular, it will explore how support workers and their clients reach for metaphor as a way of exploring options and expressing the inexpressible. By interviewing the bereaved and their support workers, we aim to provide guidance to agencies like Miscarriage Association (MA), the Stillbirth and Neonatal Death Charity (SANDS), and the Antenatal Results and Choices charity (ARC) in order to help them improve their communications with their clients. We will work together to produce material for their websites and will provide briefing documents for training sessions for staff. Beyond these immediate aims, we hope that by working directly with these agencies as our partners, our research results will contribute to the raising of public awareness about the options for the disposal of the remains of pregnancy, and enable productive debate about, and improvement of, those options.

In later years, information on certain congenital anomalies occurring in live births, stillbirths, miscarriages and terminations had also been included. In 2011, a more detailed data collection form was used and a new system for classifying the cause of death was introduced. The quality and completeness of information improved and causes of death reflected modern practice and knowledge.

Birth weight for GA at death (stillbirths) or delivery (live births) by the SCRN algorithm [17]. Percentages may add to slightly more or less than 100% because of rounding.aUnadjusted OR for stillbirth for infants with birth weight in the percentile group shown compared to infants in the reference group from a logistic regression model that included effects for percentile group only.bAnalysis weights that accounted for the basic study design plus other aspects of the sampling were used.In the subset used to assess risk of preterm stillbirth, unweighted sample sizes were 433 preterm stillbirths and 1,821 (preterm and term) live births. In the subset of term pregnancies, unweighted sample sizes were 94 stillbirths and 1,386 live births.cIndividualized norm percentiles were derived using the fetal weight for GA equation from Bukowski et al. [15].dUltrasound norm percentiles were derived using the fetal weight for GA equation and standard error from Hadlock et al. [19].eAlexander et al. population norm percentiles of birth weight for GA were used [18].Simple linear interpolation was used with the Alexander et al. birth weight percentiles reported for completed weeks of GA in whole weeks to derive birth weight percentiles for GA in weeks and days.LB, live birth; SB, stillbirth.

Materials and Methods

Experts in abortion and mental health research were consulted in preparing a questionnaire into the prevalence and effects of abortions that conflict with women’s own maternal preferences and moral beliefs.

Study Population

Invitations to complete a topic blind survey were electronically distributed to Cint.com panelists over a three-day period in July of 2024. Cint panelists are persons who voluntarily complete surveys using their own electronic devices in exchange for small rewards with a value, for this invitation, of under $2 per completed survey. The Cint survey panels include over 28 million U.S. residents. For this survey, a random sample of United States residents Cint pre-identified as females 41 to 45 years of age were invited to complete a survey housed on the LimeSurvey.org platform without any disclosure of the subject matter. The narrow age range, 41-45 years of age, was chosen to (a) eliminate the confounding effects of age, and (b) to maximize the proportion of respondents with a history of abortion since this age group will have completed the majority of their reproductive lives. Investigation of younger women has been deferred until we can test the survey instrument with this limited age group.

The survey exposure rate, response rates, and exclusion rates are shown in Figure 1. Respondents who did not complete all questions were excluded from the analysis, as were any respondents who were out of our gender and age range. Among the 2,361 people who completed the first page of demographic questions, 123 (5.2%) dropped by failing to complete the psychiatric history and another 25 (1.1%) dropped out when presented with questions relating to abortion. Another 22 (1.0%) dropped out when asked their own pregnancy outcomes histories and 166 (7.0%) dropped out, after reporting their pregnancy histories, before completing the survey. The survey was designed to be completed in approximately five to seven minutes by respondents reporting any pregnancies. Of those who completed the survey, 100 (4.6%) were excluded for completing the survey in an unreasonably short period of time, under four minutes. The exclusion of these “speedsters” reflected the likelihood that some respondents, seeking to earn credit for completing the survey as quickly as possible, were randomly responding without reading or considering the questions.

Figure 1: Study Population

Variables used

The first page of the questionnaire asked about age and gender to qualify respondents. The second page included a list of eleven mental health diagnoses and asked respondents to identify which, if any, they had ever been diagnosed.

Only after this page were respondents asked if they had ever had an “unplanned, mistimed, unwanted, or otherwise difficult pregnancy,” which was defined and thereafter referred to as a “problematic pregnancy.” They were then asked to identify the number of times they had “given birth to a live born child,” “had a miscarriage, still birth or other pregnancy loss” and “had an induced abortion.” From this pregnancy history women were divided by a program algorithm into one of five groups, by order of priority: those who had a history of induced abortions, had experienced natural pregnancy losses, had problematic pregnancies carried to term, or had live births, or had never been pregnant. Results from this grouping is shown in Table 1. Notably, given the algorithm prioritization, women in the abortion group may also have had one or more live births, natural pregnancy losses, and problematic pregnancies ending in a live birth. But women were included in the live birth group only if they had none of the other pregnancy outcomes.

The rest of the variables are described in the repository document "2nd USA Survey Instrument.pdf" and in the limesurvey code, "2nd USA survey limesurvey.lss."

STROBE checklist. (DOC)

Babies with a condition are included if the pregnancy is live born and suspected and/or diagnosed within their first year; a spontaneous still birth at 24 weeks and over; miscarriage at 23 weeks and under or a termination of pregnancy at any gestation.

The register includes babies from pregnancies ending in January 2021 onwards, where the baby meets this inclusion criteria. The register will be extended in the future to also collect and hold information on other rare diseases.

The study investigated whether working as a hairdresser has a negative impact on fertility, measured as time to pregnancy and miscarriage risk. Methods: Self-administered questionnaires were sent to 5289 Swedish hairdressers (response rate 50%) and to 5299 age-matched women from the general Swedish population (response rate 54%). Information was collected on time to pregnancy or trying time for women who had tried, but failed, to conceive at the time of the study. The outcome of the pregnancy was determined and categorized as either miscarriage or stillbirth or live birth. The hairdressers were compared with the referents with respect to these two outcomes. Within the hairdresser cohort, the effects of hair treatments, as well as physical workload and stress were investigated. Results: The hairdressers were less successful than the reference cohort in conceiving (fecundability ratio 0.91, 95% confidence interval 0.83-0.99). The effect was reduced after first-month conceptions were excluded, the indication being that the effect may be the result of birth control bias. Within the hairdresser cohort, a selfperceived stressful work situation seemed to prolong the time to pregnancy. No effects were found for the different chemical hair treatments. There was no cohort difference with respect to miscarriage risk (odds ratio 1.12, 95% confidence interval 0.88-1.42), but miscarriage risks were increased for most of the hair treatments and for self-perceived stressful work situations. However, none of these effects were statistically significant. Conclusions: The present study indicates a negative impact on time to pregnancy and miscarriage risk for working as a hairdresser.

Purpose:

To investigate whether working as a hairdresser has a negative impact on female fertility

The British National Surveys of Sexual Attitudes and Lifestyles, or Natsal, are among the largest and most detailed studies of sexual behaviour in the world. Three Natsal surveys have taken place to date: Natsal-1 in 1990-1991 (available from the UK Data Archive under SN 3434), Natsal-2 in 1999-2001 (available under SN 5223) and Natsal-3 in 2010-2012 (available under SN 7799, and for Secure Access versions SN 8178 and SN 8179). Further information is available from the Natsal website.
The National Survey of Sexual Attitudes and Lifestyles, 2010-2012 is the third survey in the series. Natsal-3 aimed to provide up-to-date information on key sexual behaviours and risk factors, as well as to look at trends over time by including comparable measures to those used in the previous two surveys, and to include new questions and an extended age range to take account of current information needs in the field of sexual health.

The main objectives of Natsal-3 were to:

• provide a detailed understanding of patterns and variability of sexual behaviour in Britain (including, for example, numbers of sexual partners, frequency of different sexual practices, and homosexual experience)
• provide self-reported estimates of a range of sexual and reproductive health outcomes (including, for example, pregnancy, STI diagnosis, contraception use) and health service use
• explore sexual behaviour and function over the life-course by including an older age group (up to age 74)
• describe changes in sexual activity over time and trends in relationships, reproductive history and patterns of fertility (using Natsal-1, Natsal-2 and Natsal-3)
• from urine samples, measure the prevalence of Chlamydia trachomatis, Neisseria gonorrhoeae, type-specific Human Papillomavirus, HIV antibody and Mycoplasma genitalium
• measure the gender-specific distribution of salivary testosterone and its relationship to sexual behaviour, function and ageing

Secure Access Datasets
The Natsal-3 Secure Access datasets include additional variables considered too sensitive or disclosive for release under standard End User Licence (EUL) conditions. Additional variables available in the Secure Access studies (SNs 8178 and 8179) include:

• detailed geographic variables, including Local Authority Districts and Area Classification for Output Areas Subgroups
• respondent month of birth
• age when had hysterectomy
• month and year of first and most recent sex with partners
• outcomes of pregnancies
• age at first stillbirth
• variables relating to abortions
• age at miscarriage, abortion or still birth
• month of last pregnancy
• genders and month of birth of children
• number of children gave birth to in multiple births
• ungrouped ethnic group
• age when first and last injected non-prescribed drugs
• dates (months) relating to live-in partners
• qualifications
• Indices of Multiple Deprivation

This study, SN 8179 (National Survey of Sexual Attitudes and Lifestyles, 2010-2012: Biological Data: Secure Access), includes all the variables listed above, plus variables relating to urine and saliva sample tests, including:

• chlamydia
• gonorrhoea
• Mycoplasma genitalium
• HIV
• HPV
• Trichomonas vaginalis
• salivary testosterone level

This dataset presents information on COVID-19 vaccinations delivered to pregnant women in Scotland. In Scotland the Pfizer/BioNTech vaccine has been used since the start of the vaccination programme on 8 December 2020. The Oxford/Astrazeneca vaccine has been used from 4 January 2021 and the Moderna vaccine from 7 April 2021. Women can receive a first or second dose, or both doses, of COVID-19 vaccination during pregnancy, depending on when they become eligible for vaccination and how this relates to the dates of their pregnancy. PHS has generated this information on COVID-19 vaccinations delivered to pregnant women by linking national data on vaccinations to the COVID-19 in Pregnancy in Scotland (COPS) study database of pregnant women in Scotland. As part of the COPS study, PHS is regularly linking together a wide range of health records to identify women who are, or recently have been, pregnant. The specific records used include: - Records of booking for antenatal care - GP records relating to miscarriage - Hospital discharge records relating to miscarriage or delivery of a live or stillborn baby - Statutory termination of pregnancy notification records - Statutory live or stillbirth registration records - NHS live birth notification records. Using these records, we have identified all women in Scotland who were pregnant on 1 March 2020 (the start of the COVID-19 pandemic), and all women who have subsequently become pregnant. The study database is refreshed every month with new pregnancies added to the database, and previous records of ongoing pregnancies updated as required, for example if a woman has recently delivered her baby. Further details on the COPS study are available on the Usher Institute webpage and PHS github page.

Abstract Background Observational studies have reported maternal short/long sleep duration to be associated with adverse pregnancy and perinatal outcomes. However, it remains unclear whether there are nonlinear causal effects. Our aim was to use Mendelian randomization (MR) and multivariable regression to examine nonlinear effects of sleep duration on stillbirth (MR only), miscarriage (MR only), gestational diabetes, hypertensive disorders of pregnancy, perinatal depression, preterm birth and low/high offspring birthweight. Methods We used data from European women in UK Biobank (N=176,897), FinnGen (N=~123,579), Avon Longitudinal Study of Parents and Children (N=6826), Born in Bradford (N=2940) and Norwegian Mother, Father and Child Cohort Study (MoBa, N=14,584). We used 78 previously identified genetic variants as instruments for sleep duration and investigated its effects using two-sample, and one-sample nonlinear (UK Biobank only), MR. We compared MR findings with multivariable regression in MoBa (N=76,669), where maternal sleep duration was measured at 30 weeks. Results In UK Biobank, MR provided evidence of nonlinear effects of sleep duration on stillbirth, perinatal depression and low offspring birthweight. Shorter and longer duration increased stillbirth and low offspring birthweight; shorter duration increased perinatal depression. For example, longer sleep duration was related to lower risk of low offspring birthweight (odds ratio 0.79 per 1 h/day (95% confidence interval: 0.67, 0.93)) in the shortest duration group and higher risk (odds ratio 1.40 (95% confidence interval: 1.06, 1.84)) in the longest duration group, suggesting shorter and longer duration increased the risk. These were supported by the lack of evidence of a linear effect of sleep duration on any outcome using two-sample MR. In multivariable regression, risks of all outcomes were higher in the women reporting <5 and ≥10 h/day sleep compared with the reference category of 8–9 h/day, despite some wide confidence intervals. Nonlinear models fitted the data better than linear models for most outcomes (likelihood ratio P-value=0.02 to 3.2×10−52), except for gestational diabetes. Conclusions Our results show shorter and longer sleep duration potentially causing higher risks of stillbirth, perinatal depression and low offspring birthweight. Larger studies with more cases are needed to detect potential nonlinear effects on hypertensive disorders of pregnancy, preterm birth and high offspring birthweight.