Malodour classification with low-cost flexible electronics.

Understanding body malodour in a measurable manner is essential for developing personal care products. Body malodour is the result of bodily secretion of a highly complex mixture of volatile organic compounds. Current body malodour measurement methods are manual, time consuming and costly, requiring an expert panel of assessors to assign a malodour score to each human test subject. This article proposes a technology-based solution to automate this task by developing a custom-designed malodour score classification system comprising an electronic nose sensor array, a sensor readout interface and a machine learning hardware fabricated on low-cost flexible substrates. The proposed flexible integrated smart system is to augment the expert panel by acting like a panel assessor but could ultimately replace the panel to reduce the test and measurement costs. We demonstrate that it can classify malodour scores as good as or even better than half of the assessors on the expert panel.

Maternal factors and risk of spontaneous preterm birth due to high ambient temperatures in New South Wales, Australia.

BACKGROUND: Exposure to high ambient temperatures has been shown to increase the risk of spontaneous preterm birth. Determining which maternal factors increase or decrease this risk will inform climate adaptation strategies. OBJECTIVES: This study aims to assess the risk of spontaneous preterm birth associated with exposure to ambient temperature and differences in this relationship between mothers with different health and demographic characteristics. METHODS: We used quasi-Poisson distributed lag non-linear models to estimate the effect of high temperature-measured as the 95th percentile of daily minimum, mean and maximum compared with the median-on risk of spontaneous preterm birth (23-36 weeks of gestation) in pregnant women in New South Wales, Australia. We estimated the cumulative lagged effects of daily temperature and analyses on population subgroups to assess increased or decreased vulnerability to this effect. RESULTS: Pregnant women (n = 916,678) exposed at the 95th percentile of daily mean temperatures (25ºC) had an increased risk of preterm birth (relative risk 1.14, 95% confidence interval 1.07, 1.21) compared with the median daily mean temperature (17℃). Similar effect sizes were seen for the 95th percentile of minimum and maximum daily temperatures compared with the median. This risk was slightly higher among women with diabetes, hypertension, chronic illness and women who smoked during pregnancy. CONCLUSIONS: Higher temperatures increase the risk of preterm birth and women with pre-existing health conditions and who smoke during pregnancy are potentially more vulnerable to these effects.

Health care provider support and factors associated with breastfeeding beyond infancy: A cross-national study.

BACKGROUND: Breastfeeding beyond infancy (12 months) remains atypical in the United States, United Kingdom, Canada, and Australia, and the role of health care providers is unclear. The objective of this study was to compare women's perceptions of provider support and other factors affecting breastfeeding beyond infancy across countries, among women who had each successfully breastfed at least one child that long. METHODS: Women completed an online questionnaire distributed via La Leche League, USA (2013), about sources and ratings of support for breastfeeding for their oldest child who was breastfed at least 12 months and participant demographics. Multivariable log-binomial regression was used to compare ratings of health care provider support and the importance of 13 factors by country. RESULTS: Some similarities and many differences were observed across countries in support received from providers, whereas modest or no differences were observed in the importance women placed on factors like health benefits and enjoyment of breastfeeding. Of 59 581 women, less than half discussed their decision to breastfeed beyond infancy with their child's provider. United Kingdom women rated their comfort in discussing breastfeeding beyond 12 months with their providers and the support received as lower than United States women. Canadian women gave lower ratings than United States women, but inconsistently. Australian women rarely differed from United States women in their responses. Providers' recommendations were not important to the decision to breastfeed beyond infancy, especially for United Kingdom women. DISCUSSION: Rates of breastfeeding beyond infancy are low in these countries; improving provider support may help achieve global breastfeeding goals.

Comparison of trauma management between two major trauma services in Riyadh, Kingdom of Saudi Arabia and Melbourne, Australia.

INTRODUCTION: The burden of injury in the Kingdom of Saudi Arabia (KSA) has increased in recent years, but the country has lacked a consistent methodology for collecting injury data. A trauma registry has been established at a large public hospital in Riyadh from which these data are now available. OBJECTIVES: We aimed to provide an overview of trauma epidemiology by reviewing the first calendar year of data collection for the registry. Risk-adjusted analyses were performed to benchmark outcomes with a large Australian major trauma service in Melbourne. The findings are the first to report the trauma profile from a centre in the KSA and compare outcomes with an international level I trauma centre. METHODS: This was an observational study using records with injury dates in 2018 from the registries at both hospitals. Demographics, processes and outcomes were extracted, as were baseline characteristics. Risk-adjusted endpoints were inpatient mortality and length of stay. Binary logistic regression was used to measure the association between site and inpatient mortality. RESULTS: A total of 2436 and 4069 records were registered on the Riyadh and Melbourne databases, respectively. There were proportionally more men in the Saudi cohort than the Australian cohort (86% to 69%). The Saudi cohort was younger, the median age being 36 years compared with 50 years, with 51% of injuries caused by road traffic incidents. The risk-adjusted length of stay was 4.4 days less at the Melbourne hospital (95% CI 3.95 days to 4.86 days, p<0.001). The odds of in-hospital death were also less (OR 0.25; 95% CI 0.15 to 0.43, p<0.001). CONCLUSIONS: This is the first hospital-based study of trauma in the kingdom that benchmarks with an individual international centre. There are limitations to interpreting the comparisons, however the findings have established a baseline for measuring continuous improvement in outcomes for KSA trauma services.

Rates of neonatal morbidity by maternal region of birth and gestational age in New South Wales, Australia 2003-2016.

INTRODUCTION: Research suggests that neonatal morbidity differs by maternal region of birth at different gestational ages. This study aimed to determine the overall and gestation-specific risk of neonatal morbidity by maternal region of birth, after adjustment for maternal, infant and birth characteristics, for women giving birth in New South Wales, Australia, from 2003 to 2016. MATERIAL AND METHODS: The study utilized a retrospective cohort study design using linked births, hospital and deaths data. Modified Poisson regression was used to determine risk with 95% confidence intervals (95% CI) of neonatal morbidity by maternal region of birth, overall and at each gestational age, compared with Australian or New Zealand-born women giving birth at 39 weeks. RESULTS: There were 1 074 930 live singleton births ≥32 weeks' gestation that met the study inclusion criteria, and 44 394 of these were classified as morbid, giving a neonatal morbidity rate of 4.13 per 100 live births. The gestational age-specific neonatal morbidity rate declined from 32 weeks' gestation, reaching a minimum at 39 weeks in all maternal regions of birth. The unadjusted neonatal morbidity rate was highest in South Asian-born women at most gestations. Adjusted rates of neonatal morbidity between 32 and 44 weeks were significantly lower for babies born to East (adjusted relative risk [aRR] 0.65, 95% CI 0.62-0.68), South-east (aRR 0.76, 95% CI 0.73-0.79) and West Asian-born (aRR 0.93, 95% CI 0.88-0.98) mothers, and higher for babies of Oceanian-born (aRR 1.11, 95% CI 1.04-1.18) mothers, compared with Australian or New Zealand-born mothers. Babies of African, Oceanian, South Asian and West Asian-born women had a lower adjusted risk of neonatal morbidity than Australian or New Zealand-born women until 37 or 38 weeks' gestation, and thereafter an equal or higher risk in the term and post-term periods. CONCLUSIONS: Maternal region of birth is an independent risk factor for neonatal morbidity in New South Wales.

Pregnancy outcomes for women with a history of stroke: A population-based record linkage study.

BACKGROUND: Little is known about the pregnancy outcomes of women who have had a stroke prior to a first pregnancy. AIM: To identify a cohort of primiparous women giving birth to a single baby and compare the pregnancy outcomes of those with a pre-pregnancy stroke hospitalisation record to those without a stroke hospitalisation record. MATERIALS AND METHODS: Record linkage study of all primiparous women aged 15-44 years with singleton pregnancies birthing in New South Wales, Australia from 2003 to 2015. Stroke was identified from 2001 to 2015 hospital data using International Classification of Diseases tenth Edition - Australian Modification codes I60-64. Women whose first hospital record of stroke was during pregnancy or <42 days after birth were excluded. Outcomes included diabetes or hypertension during pregnancy, mode of delivery, haemorrhage, severe maternal morbidity (validated composite outcome indicator), gestational age at birth, Apgar score (1 min < 7), and small-for-gestational age. RESULTS: Of 487 767 women with a first pregnancy, 124 (2.5/10 000) had a hospital record which included a pre-pregnancy stroke diagnosis. Women with a stroke history were more likely to have an early-term delivery (37-38 weeks; relative risk (RR) 1.49, 95% CI 1.17-1.90) and a pre-labour caesarean (RR 2.83, 95% CI 2.20-3.63). There were no significant differences in other maternal or neonatal outcomes. CONCLUSION: This is the largest reported study of pregnancy and birth outcomes for women with a history of stroke. With the exception of pre-labour caesarean, there were no differences in pregnancy outcomes for women with a history of stroke compared with women with no history of stroke.

Outcomes of Subsequent Births After Placenta Accreta Spectrum.

OBJECTIVE: To investigate subsequent birth rates, maternal and neonatal outcomes for women with a history of placenta accreta spectrum (placenta accreta, increta, and percreta). METHODS: A population-based record linkage study of women who had a first, second, or third birth in New South Wales from 2003 to 2016 was conducted. Data were obtained from birth and hospital records and death registrations. Women with a history of placenta accreta spectrum were matched to women without, on propensity score and parity, to compare outcomes with women who had similar risk profiles. Modified Poisson regression models were used to calculate adjusted relative risk (aRR) for a range of maternal and neonatal outcomes. RESULTS: We identified recurrent placenta accreta spectrum in 27/570 (4.7%, 95% CI 3.0-6.5%) of second and 9/119 (7.6%, 95% CI 2.8-12.3%) of third pregnancies after placenta accreta spectrum in the preceding birth, with an overall recurrence rate of 38/689 (5.5%, 95% CI 3.9-7.5%, compared with the population prevalence of 25.5/10,000 births (95% CI 24.6-26.4). Subsequent births after placenta accreta spectrum had higher risk of postpartum hemorrhage (aRR 1.51, 95% CI 1.19-1.92), transfusion (aRR 2.13, 95% CI 1.17-3.90), cesarean delivery (aRR 1.19, 95% CI 1.02-1.37), manual removal of placenta (aRR 6.92, 95% CI 3.81-12.55), and preterm birth (aRR 1.43, 95% CI 1.03-1.98), with lower risk of small for gestational age (aRR 0.64, 95% CI 0.43-0.96), compared with similar-risk births. CONCLUSION: Women with a history of placenta accreta spectrum have increased risk of maternal morbidity, preterm birth, and placenta accreta spectrum in the subsequent pregnancy compared with similar-risk women with no previous placenta accreta spectrum, although the absolute risks are generally low. These findings may be used to inform counseling of women on the risks of future pregnancies.

Determining a strategy to reduce smoking in pregnancy.

BACKGROUND: Further efforts, informed by current data, are needed to reduce smoking during pregnancy. AIMS: To describe trends in smoking during pregnancy and identify regions most likely to benefit from targeted smoking cessation interventions, in New South Wales (NSW), Australia. MATERIALS AND METHODS: All women who gave birth in NSW between 1994 and 2016 were included. Smoking status was identified from the Perinatal Data Collection. For births between 2012 and 2016, women were grouped into Local Health District (LHD) of residence, and smoking rates calculated. The impacts of a hypothetical smoking cessation intervention in four LHDs with (i) high smoking rates and (ii) high numbers of smokers, were compared. RESULTS: The overall smoking rate during pregnancy decreased from 22.1% in 1994 to 8.3% in 2016. [Correction added on 13 August 2020, after first online publication: the overall smoking rate during pregnancy in 1994 has been corrected from 14.5% to 22.1%.]. The decrease was lowest among women living in the most socioeconomically disadvantaged areas (41%) and highest among those living in the most advantaged areas (83%). Between 2012 and 2016, over half the women who smoked during pregnancy lived in one of four LHDs. Only 1% of women reporting smoking during pregnancy resided in the LHD with the highest smoking rate (34.7%). A simulated intervention targeting only four regions showed greater effect on the statewide smoking rate when targeting LHDs with high numbers of smokers rather than high smoking rates. CONCLUSIONS: Despite decreases in rates of smoking during pregnancy, there was evidence of geographic clustering of smokers. The greatest reduction in overall smoking may come from interventions targeting the four LHDs with the highest number of smokers.

Adverse birth outcomes in Victoria, Australia in association with maternal exposure to low levels of ambient air pollution.

BACKGROUND: The relationship between maternal exposure to air pollution and birth outcomes is not well characterised where ambient air pollution is relatively low. OBJECTIVES: We aimed to explore the association between maternal exposure to ambient nitrogen dioxide (NO2) and fine particulate matter (PM2.5) and a range of birth outcomes in Victoria, Australia. Secondary aims were to explore whether obstetric conditions, such as gestational diabetes mellitus (GDM) and hypertensive disorders of pregnancy, were effect modifiers in observed relationships. METHODS: We included all singleton births occurring in Victoria, Australia from 1st March 2012 to 31st December 2015 using routinely collected government data. Outcomes included birth weight, small for gestational age (SGA), term low birth weight (tLBW), large for gestational age (LGA), and spontaneous preterm birth (sPTB). We estimated exposure to annual ambient NO2 and PM2.5 concentrations, assigned to maternal residence at time of birth. Confounders included maternal, meteorological and temporal variables. Multivariable linear regression and log-binomial regression were used for continuous and dichotomous outcomes, respectively. RESULTS: There were 285,594 births during the study period. Average NO2 exposure was 6.0 parts per billion (ppb, median 5.6; interquartile range (IQR) 3.9) and PM2.5 was 6.9 µg/m3 (median 7.1, IQR 1.3). IQR increases in ambient NO2 and PM2.5 were associated with fetal growth restriction, including decrements in birth weight (NO2 ß -22.8 g; 95%CI -26.0, -19.7; PM2.5 ß -14.8 g; 95%CI -17.4, -12.2) and increased risk of SGA (NO2 RR 1.08; 95%CI 1.06, 1.10; PM2.5 RR 1.05; 95%CI 1.04, 1.07) and tLBW (NO2 RR 1.06; 95%CI 1.01, 1.10; PM2.5 RR 1.04; 95%CI 1.03, 1.08). Women with GDM and hypertensive disorders of pregnancy had greater decrements in birth weight in association with pollutant exposure. DISCUSSION: In this exploratory study using an annual metric of exposure, maternal exposure to low-level ambient air pollution was associated with fetal growth restriction, which carries substantial public health implications.

Evaluation of Minimum Unit Pricing of Alcohol: A Mixed Method Natural Experiment in Scotland.

In May 2018, Scotland became the first country in the world to implement minimum unit pricing (MUP) for all alcoholic drinks sold in licensed premises in Scotland. The use of a Sunset Clause in the MUP legislation was a factor in successfully resisting legal challenges by indicating that the final decision on a novel policy would depend on its impact. An overarching evaluation has been designed and the results will provide important evidence to inform the parliamentary vote on the future of MUP in Scotland. The evaluation uses a mixed methods portfolio of in-house, commissioned, and separately funded studies to assess the impact of MUP across multiple intended and unintended outcomes related to compliance, the alcoholic drinks industry, consumption, and health and social harms. Quantitative studies to measure impact use a suitable control where feasible. Qualitative studies assess impact and provide an understanding of the lived experience and mechanism of change for key sub-groups. As well as providing important evidence to inform the parliamentary vote, adding to the international evidence on impact and experience of alcohol pricing policy across a broad range of outcomes, this approach to evaluating novel policy interventions may provide guidance for future policy innovations.

Maternal Exposure to Ambient Air Pollution and Pregnancy Complications in Victoria, Australia.

The relationship between maternal exposure to ambient air pollution and pregnancy complications is not well characterized. We aimed to explore the relationship between maternal exposure to ambient nitrogen dioxide (NO2) and fine particulate matter (PM2.5) and hypertensive disorders of pregnancy, gestational diabetes mellitus (GDM) and placental abruption. Using administrative data, we defined a state-wide cohort of singleton pregnancies born between 1 March 2012 and 31 December 2015 in Victoria, Australia. Annual average NO2 and PM2.5 was assigned to maternal residence at the time of birth. 285,594 singleton pregnancies were included. An IQR increase in NO2 (3.9 ppb) was associated with reduced likelihood of hypertensive disorders of pregnancy (RR 0.89; 95%CI 0.86, 0.91), GDM (RR 0.92; 95%CI 0.90, 0.94) and placental abruption (RR 0.81; 95%CI 0.69, 0.95). Mixed observations and smaller effect sizes were observed for IQR increases in PM2.5 (1.3 µg/m3) and pregnancy complications; reduced likelihood of hypertensive disorders of pregnancy (RR 0.95; 95%CI 0.93, 0.97), increased likelihood of GDM (RR 1.02; 95%CI 1.00, 1.03) and no relationship for placental abruption. In this exploratory study using an annual metric of exposure, findings were largely inconsistent with a priori expectations and further research involving temporally resolved exposure estimates are required.

Preterm birth, unplanned hospital contact, and mortality in infants born to teenage mothers in five countries: An administrative data cohort study.

BACKGROUND: Young maternal age is associated with lower birthweight and higher rates of preterm birth and childhood hospitalisations. Internationally, teen pregnancy rates vary widely, reflecting differences in social, welfare, and health care factors in different cultural contexts. OBJECTIVES: To determine whether the increased risk of adverse infant outcomes among teenage mothers varies by country, reflecting different national teenage birth rates and country-specific social/welfare policies, in Scotland (higher teenage pregnancy rates), England, New South Wales (NSW; Australia), Ontario (Canada), and Sweden (lower rates). METHODS: We used administrative hospital data capturing 3 002 749 singleton births surviving to postnatal discharge between 2010 and 2014 (2008-2012 for Sweden). We compared preterm birth (24-36 weeks' gestation), mortality within 12 months of postnatal discharge, unplanned hospital admissions, and emergency department visits within 12 months of postnatal discharge, for infants born to mothers aged 15-19, 20-24, 25-29, and 30-34 years. RESULTS: Compared to births to women aged 30-34 years, risks of adverse outcomes among teenage mothers were higher in all countries, but the magnitude of effects was not related to country-specific rates of teenage births. Teenage mothers had between 1.2% (95% confidence interval [CI] 0.7, 1.7, Sweden) and 2.0% (95% CI 1.4, 2.5, NSW) more preterm births, and between 9.8 (95% CI 7.2, 12.4, England) and 19.7 (95% CI 8.7, 30.6, Scotland) more deaths per 10 000 infants, compared with mothers aged 30-34. Between 6.4% (95% CI 5.5, 7.4, NSW) and 25.4% (95% CI 24.7, 26.1, Ontario), more infants born to teenage mothers had unplanned hospital contacts compared with those born to mothers aged 30-34. CONCLUSIONS: Regardless of country, infants born to teenage mothers had universally worse outcomes than those born to older mothers. This excess risk did not vary by national rates of livebirths to teenage mothers. Current mechanisms to support teenage mothers have not eliminated maternal age-related disparities in infant outcomes; further strategies to mitigate excess risk in all countries are needed.

Rates of stillbirth by maternal region of birth and gestational age in New South Wales, Australia 2004-2015.

BACKGROUND: Research suggests that in Australia, maternal region of birth is a risk factor for stillbirth. AIMS: We aimed to examine the relationship between stillbirth and maternal region of birth in New South Wales (NSW), Australia from 2004 to 2015. METHODS: Adjusted logistic regression was used to determine odds of stillbirth by maternal region of birth, compared with Australian or New Zealand-born (AUS/NZ-born) women. Intervention rates (induction or pre-labour caesarean) by maternal region of birth, over time, were also examined. Interaction terms were used to assess change in relative odds of stillbirth, over two time periods (2004-2011 and 2012-2015). RESULTS: There were 944 457 singleton births ≥24 weeks gestation that met the study inclusion criteria and 3221 of these were stillbirths, giving a stillbirth rate of 3.4 per 1000 births. After adjustment for confounders, South Asian (adjusted odds ratio (aOR) 1.42, 95% CI 1.24-1.62), Oceanian (aOR 1.45, 95% CI 1.17-1.80) and African (aOR 1.46, 96% CI 1.19-1.80) born women had significantly higher odds of stillbirth that AUS/NZ-born women. Intervention rates increased from the earlier to the later time period by 13.1% across the study population, but the increase was larger in African and South Asian-born women (18.1% and 19.6% respectively) than AUS/NZ-born women (11.2%). There was a significant interaction between ethnicity and time period for South Asian-born women in the all-births model, with their stillbirth rates becoming closer to AUS/NZ-born women in the later period. CONCLUSION: South Asian, African and Oceanian maternal region of birth are independent risk factors for stillbirth in NSW.

Experience gained from the implementation of the Saudi TraumA Registry (STAR).

BACKGROUND: Trauma registries are essential to trauma systems, to enable collection of the data needed to enhance clinical knowledge and monitor system performance. The King Saud Medical City (KSMC) in Riyadh, Kingdom of Saudi Arabia (KSA) is aiming to become a Level 1 Trauma Centre, and required a trauma registry in order to do so. Our objective was to establish the Saudi TraumA Registry (STAR) at the (KSMC) and ready it for national deployment. The challenge was that no formal trauma data collection had occurred previously and clinicians had no prior experience of trauma registries. METHODS: To develop the registry, a novel 12 step implementation plan was created and followed at the KSMC. Registry criteria and a Minimum Dataset were selected; training was delivered; database specifications were written; operating procedures were developed and regular reporting was initiated. RESULTS: Data collection commenced on August 1st 2017. The registry was fully operational by April 2018, eight months ahead of schedule. During the first year of data collection an average of 216 records per month were entered into the database. An inaugural report was presented at the Saudi Trauma Conference in February 2019. CONCLUSIONS: The strategy deployed at the KSMC has successfully established the STAR. In the short term, process indicators will track the development of the hospital into a Level 1 Trauma Centre. In the medium to long term the STAR will be rolled out nationally to capture the impact of public health initiatives aimed at reducing injury in the KSA. The effect of the STAR will be that the country is better equipped to deliver continuous improvements in trauma systems and quality of care.

Comparison of group O Rh(D)- red blood cell use in pregnant women across hospitals of various sizes and obstetric capabilities prior to the introduction of patient blood management guidelines.

BACKGROUND: O Rh(D)- red blood cell (RBC) units can generally be transfused to most patients regardless of their ABO blood type and are frequently used during emergency situations. Detailed usage patterns of O Rh(D)- RBC units in obstetric populations have not been well characterised. With the introduction of patient blood management guidelines, historical usage patterns are important for providing comparative data. AIMS: To determine how the use of O Rh(D)- RBC units in pregnant women differs between hospitals of different sizes and obstetric capabilities prior to patient blood management guidelines. METHODS: Data from 67 New South Wales public hospital blood banks were linked with hospital and perinatal databases to identify RBC transfusions during pregnancy, birth and postnatally between July 2006 and December 2010. RBC transfusions were divided into O Rh(D)- or other blood types. Hospitals were classified according to birth volume, obstetric capability and location, with transfusions classified by timing and diagnosis. RESULTS: Of the 12 078 RBC units transfused into pregnant women, 1062 (8.8%) were O Rh(D)-. Higher use of O Rh(D)- RBC units was seen in antenatal transfusions, preterm deliveries and in regional or smaller hospitals. There was wide variation in rates of O Rh(D)- RBC transfusion among hospitals. CONCLUSIONS: The rate of O Rh(D)- RBC unit use in obstetrics was lower during the period assessed than the nationally reported usage. It is encouraging that O Rh(D)- RBCs were more commonly used in emergency or specialised situations, or in facilities where holding a large blood inventory is not feasible.

Maternal exposure to fine particulate matter from a large coal mine fire is associated with gestational diabetes mellitus: A prospective cohort study.

BACKGROUND: In 2014, the Hazelwood coal mine fire was an unprecedented event that resulted in a six-week period of poor air quality in the Latrobe Valley in regional Australia. We aimed to determine whether maternal exposure to fine particulate matter in coal mine fire smoke was associated with selected obstetric complications, including gestational diabetes mellitus, hypertensive disorders of pregnancy and abnormal placentation. METHODS: We defined a complete cohort of pregnant women with births >20 weeks in the Latrobe Valley from March 1, 2012-Dec 31, 2015 utilising administrative perinatal data. Average and peak fine particulate matter (PM2.5) was assigned to residential address at delivery using a chemical transport model. Maternal, meteorological and temporal variables were included in final log-binomial regression models. RESULTS: 3612 singleton pregnancies were included in the analysis; 766 were exposed to the smoke event. Average maternal PM2.5 exposure was 4.4 µg/m3 (SD 7.7; IQR 2.12). Average peak PM2.5 exposure was 44.9 µg/m3 (SD 57.1; IQR 35.0). An interquartile range increase in peak PM2.5 was associated with a 16% increased likelihood of gestational diabetes mellitus (95%CI 1.09, 1.22; <0.0001). Whereas, an interquartile range increase in average PM2.5 was associated with a 7% increased likelihood of gestational diabetes mellitus (95%CI 1.03, 1.10; <0.0001). Second trimester exposure was of critical importance. No association for hypertensive disorders or abnormal placentation was observed. CONCLUSION: this is the first study to examine obstetric complications relating to a discrete smoke event. These findings may guide the public health response to future similar events.

Gestational age, morbidity and mortality among twin births in New South Wales, Australia 2003-2014: A cohort study.

BACKGROUND: Evidence suggests that the trend toward early planned births observed among singletons may be evident among twin pregnancies. AIMS: To describe trends in gestational age at birth, pregnancy characteristics, neonatal morbidity and mortality among twin pregnancies. MATERIALS AND METHODS: Population-based data linkage study of twin births of ≥30 weeks of gestation without a major congenital anomaly born in 2003-2014 in New South Wales (NSW), Australia. Linked pregnancy and birth, hospital and mortality data were used. Generalised linear regression was used to assess linear trends. Risk difference (RD) and 95% confidence intervals were estimated. RESULTS: Among 28 076 eligible twin births (14 038 pregnancies), 49% of births occurred prior to 37 weeks and 69% of births were planned (pre-labour caesarean or induction of labour). There were increases over time in the proportion of twin births at preterm gestations (30-34 weeks (RD 2.1, 95% CI 0.1, 4.0), 35-36 weeks (RD 7.5, 95% CI 5.4, 9.7)) and in the rates of planned births (pre-labour caesarean (RD 6.4, 95% CI 4.0, 8.8), induction (RD 4.6, 95% CI 2.6, 6.6)). There was no significant change in stillbirth or neonatal death rates, but there was an increase in neonatal morbidity over the study period. Concurrently, there were increases in the prevalence of gestational diabetes; and decreases in pregnancy hypertension, assisted reproductive technology use, small-for-gestational age and birthweight discordance. CONCLUSIONS: Gestational age at birth among twin births is decreasing and birth intervention is increasing. There are increasing rates of neonatal morbidity, but no overall change in perinatal mortality.

Benefits of not smoking during pregnancy for Australian Aboriginal and Torres Strait Islander women and their babies: a retrospective cohort study using linked data.

OBJECTIVES: To provide evidence for targeted smoking cessation policy, the aim of this study was to compare pregnancy outcomes of Aboriginal mothers who reported not smoking during pregnancy with Aboriginal mothers who reported smoking during pregnancy. DESIGN: Population based retrospective cohort study using linked data. SETTING: New South Wales, the most populous Australian state. POPULATION: 18 154 singleton babies born to 13 477 Aboriginal mothers between 2010 and 2014 were identified from routinely collected New South Wales datasets. Aboriginality was determined from birth records and from four linked datasets through an Enhanced Reporting of Aboriginality algorithm. EXPOSURE: Not smoking at any time during pregnancy. MAIN OUTCOME MEASURES: Unadjusted and adjusted relative risks (aRR) and 95% CIs from modified Poisson regression were used to examine associations between not smoking during pregnancy and maternal and perinatal outcomes including severe morbidity, inter-hospital transfer, perinatal death, preterm birth and small-for-gestational age. Population attributable fractions (PAFs) were calculated using adjusted relative risks. RESULTS: Compared with babies born to mothers who smoked during pregnancy, babies born to non-smoking mothers had a lower risk of all adverse perinatal outcomes including perinatal death (aRR=0.58, 95% CI 0.44 to 0.76), preterm birth (aRR=0.58, 95% CI 0.53 to 0.64) and small-for-gestational age (aRR=0.35, 95% CI 0.32 to 0.39). PAFs (%) were 27% for perinatal death, 26% for preterm birth and 48% for small-for-gestational-age. Compared with women who smoked during pregnancy (n=8919), those who did not smoke (n=9235) had a lower risk of being transferred to another hospital (aRR=0.76, 95% CI 0.66 to 0.89). CONCLUSIONS: Babies born to women who did not smoke during pregnancy had a lower risk of adverse perinatal outcomes. Rates of adverse outcomes among Aboriginal non-smokers were similar to those among the general population. These results quantify the proportion of adverse perinatal outcomes due to smoking and highlight why effective smoking cessation programme are urgently required for this population.

The association between haemoglobin levels in the first 20 weeks of pregnancy and pregnancy outcomes.

BACKGROUND: Low haemoglobin has been linked to adverse pregnancy outcomes. Our study aimed to assess the association of haemoglobin (Hb) in the first 20 weeks of pregnancy, and restoration of low Hb levels, with pregnancy outcomes in Australia. METHODS: Clinical data for singleton pregnancies from two tertiary public hospitals in New South Wales were extracted for 2011-2015. The relationship between the lowest Hb result in the first 20 weeks of pregnancy and adverse outcomes was determined using adjusted Poisson regression. Those with Hb <110 g/L were classified into 'restored' and 'not restored' based on Hb results from 21 weeks onwards, and risk of adverse outcomes explored with adjusted Poisson regression. RESULTS: Of 31,906 singleton pregnancies, 4.0% had Hb <110 and 10.2% had ≥140 g/L at ≤20 weeks. Women with low Hb had significantly higher risks of postpartum haemorrhage, transfusion, preterm birth, very low birthweight, and having a baby transferred to higher care or stillbirth. High Hb was also associated with higher risks of preterm, very low birthweight, and transfer to higher care/stillbirth. Transfusion was the only outcome where risk decreased with increasing Hb. Risk of transfusion was significantly lower in the 'restored' group compared with the 'not restored' group (OR 0.39, 95% CI 0.22-0.70), but restoration of Hb did not significantly affect the other outcomes measured. CONCLUSIONS: Women with both low and high Hb in the first 20 weeks of pregnancy had higher risks of adverse outcomes than those with normal Hb. Restoring Hb after 20 weeks did not improve most adverse outcome rates but did reduce risk of transfusion.