Whether there are differences in the contribution of overweight and obesity to adverse pregnancy outcomes between migrant and non-migrant women in high-income countries, which might increase health inequalities, remains unclear. Therefore, in this study, we aimed to estimate the contribution (including the proportion and number of attributable cases) of overweight and obesity to a wide range of adverse pregnancy outcomes in Swedish-born and migrant women. This population-based cohort study used nationwide population registries in Sweden. All outcomes and covariates were collected from the Medical Birth Register (delivery and maternal characteristics), National Patient Register (inpatient and specialised outpatient care), the Cause of Death Register (all deaths in Sweden), the Longitudinal Integrated Database for Health Insurance and Labour Market Studies (socioeconomic data), and the Total Population Register (maternal birth country data). Women with missing records of BMI at the first antenatal visit, country of birth, or covariates, were excluded from the study. BMI was measured during the first antenatal visit. Maternal country of birth was categorised into Sweden and seven super-regions. The proportion (ie, population attributable fractions [PAFs]) and the number of adverse pregnancy outcomes attributable to overweight and obesity were calculated, adjusting for maternal age, gestational age at first antenatal visit, maternal parity, smoking status, maternal somatic conditions, child's sex, socioeconomic and demographic variables. We identified 2 228 416 singleton pregnancies between Jan 1, 2000, and Dec 31, 2020 of 1 245 273 women. 254 778 (11·4%) pregnancies with missing records of BMI at the first antenatal visit, country of birth, or covariates were excluded, which resulted in a final analytical cohort of 1 973 638 pregnancies carried by 1 164 783 women. The overall mean maternal age of the study population was 30·8 years (SD 5·1). As estimated by PAFs, overweight and obesity contributed to a large proportion of adverse pregnancy outcomes: gestational diabetes (52·1% [95% CI 51·0-53·2]), large-for-gestational age (36·9% [36·2-37·6]), pre-eclampsia (26·5% [25·7-27·3]), low Apgar score (14·7% [13·5-15·9]), infant mortality (12·7% [9·8-15·7]), severe maternal morbidity (henceforth referred to as a near-miss event; 8·5% [6·0-11·0]), and preterm birth (5·0% [4·4-5·7]) in the total study population. PAFs varied between maternal birth regions. Interventions to reduce overweight and obesity have the potential to mitigate the burden of adverse pregnancy outcomes and possibly reduce inequalities in reproductive health. Therefore, public health practice and policy should prioritise efforts to prevent overweight and obesity among women of childbearing age. Swedish Research Council.

E-cigarettes are increasingly used by smokers and ex-smokers, often to support smoking cessation, but also among those who have never regularly smoked. The aim of our study is to estimate time trends in vaping prevalence among adults who have never regularly smoked and describe the profile of adult never-regular-smokers who vape. In this nationally representative, monthly cross-sectional survey in England, 153 073 participants (aged ≥18 years) were recruited from July, 2016, to April, 2024. 94 107 (61·5%) of the 153 073 participants had never regularly smoked. Logistic regression estimated associations between survey wave and current vaping, overall, and by sociodemographic characteristics and alcohol consumption. Vaping prevalence among never-regular-smokers was relatively stable up to 2021, at an average of 0·5% (95% CI 0·5-0·6) between July, 2016, and December, 2020; it then increased rapidly, reaching 3·5% (2·8-4·4) in April, 2024. This increase was largely driven by young adults (19·0% [13·9-25·4] among individuals aged 18 years) and those with higher alcohol consumption levels (22·1% [11·7-37·8%] among the heaviest drinkers). By contrast, trends among all adults (including current and former smokers) suggested the rise in vaping prevalence plateaued among all ages by early 2023. In 2023-24, 55·6% (48·2-62·8) of never-regular-smokers who vaped reported vaping daily; 81·7% (75·4-86·7) had been vaping for 6 months or more. The most used devices in 2023-24 were disposables (50·2% [42·9-57·5]) and the most commonly used e-liquids contained 20 mg/mL or more nicotine (44·6% [37·4-52·0]). The number of adults in England who vape but have never regularly smoked rose rapidly between 2021 and 2024, particularly in younger age groups and most of these individuals reported vaping regularly over a sustained period. The public health impacts of this finding will depend on what these people would otherwise be doing: it is likely that some might have smoked if vaping were not an available option (exposing them to more harm), whereas others might not have smoked or vaped. Cancer Research UK.

SummaryBackgroundSmoking is the leading behavioural risk factor for mortality globally, accounting for more than 175 million deaths and nearly 4·30 billion years of life lost (YLLs) from 1990 to 2021. The pace of decline in smoking prevalence has slowed in recent years for many countries, and although strategies have recently been proposed to achieve tobacco-free generations, none have been implemented to date. Assessing what could happen if current trends in smoking prevalence persist, and what could happen if additional smoking prevalence reductions occur, is important for communicating the effect of potential smoking policies.MethodsIn this analysis, we use the Institute for Health Metrics and Evaluation's Future Health Scenarios platform to forecast the effects of three smoking prevalence scenarios on all-cause and cause-specific YLLs and life expectancy at birth until 2050. YLLs were computed for each scenario using the Global Burden of Disease Study 2021 reference life table and forecasts of cause-specific mortality under each scenario. The reference scenario forecasts what could occur if past smoking prevalence and other risk factor trends continue, the Tobacco Smoking Elimination as of 2023 (Elimination-2023) scenario quantifies the maximum potential future health benefits from assuming zero percent smoking prevalence from 2023 onwards, whereas the Tobacco Smoking Elimination by 2050 (Elimination-2050) scenario provides estimates for countries considering policies to steadily reduce smoking prevalence to 5%. Together, these scenarios underscore the magnitude of health benefits that could be reached by 2050 if countries take decisive action to eliminate smoking. The 95% uncertainty interval (UI) of estimates is based on the 2·5th and 97·5th percentile of draws that were carried through the multistage computational framework.FindingsGlobal age-standardised smoking prevalence was estimated to be 28·5% (95% UI 27·9–29·1) among males and 5·96% (5·76–6·21) among females in 2022. In the reference scenario, smoking prevalence declined by 25·9% (25·2–26·6) among males, and 30·0% (26·1–32·1) among females from 2022 to 2050. Under this scenario, we forecast a cumulative 29·3 billion (95% UI 26·8–32·4) overall YLLs among males and 22·2 billion (20·1–24·6) YLLs among females over this period. Life expectancy at birth under this scenario would increase from 73·6 years (95% UI 72·8–74·4) in 2022 to 78·3 years (75·9–80·3) in 2050. Under our Elimination-2023 scenario, we forecast 2·04 billion (95% UI 1·90–2·21) fewer cumulative YLLs by 2050 compared with the reference scenario, and life expectancy at birth would increase to 77·6 years (95% UI 75·1–79·6) among males and 81·0 years (78·5–83·1) among females. Under our Elimination-2050 scenario, we forecast 735 million (675–808) and 141 million (131–154) cumulative YLLs would be avoided among males and females, respectively. Life expectancy in 2050 would increase to 77·1 years (95% UI 74·6–79·0) among males and 80·8 years (78·3–82·9) among females.InterpretationExisting tobacco policies must be maintained if smoking prevalence is to continue to decline as forecast by the reference scenario. In addition, substantial smoking-attributable burden can be avoided by accelerating the pace of smoking elimination. Implementation of new tobacco control policies are crucial in avoiding additional smoking-attributable burden in the coming decades and to ensure that the gains won over the past three decades are not lost.FundingBloomberg Philanthropies and the Bill & Melinda Gates Foundation.

Among people infected with measles in England between 2010 and 2019, the proportion of cases who had previously received two doses of vaccine has increased, especially among young adults. Possible explanations include rare infections in vaccinated individuals who did not gain immunity upon vaccination, made more common because fewer individuals in the population were born in the endemic era, before vaccination was introduced, and exposed as part of endemic transmission, or the waning of vaccine-induced immunity, which would present new challenges for measles control in near-elimination settings. We aimed to evaluate whether measles dynamics observed in England between 2010 and 2019 were in line with a waning of vaccine-induced immunity. We used a compartmental mathematical model stratified by age group, region, and vaccine status, fitted to individual-level case data reported in England from 2010 to 2019 and collected by the UK Health Security Agency. The deterministic model was fitted using Monte Carlo Markov Chains under three scenarios: without the waning of vaccine-induced immunity, with waning depending on time since vaccination, and with waning depending on time since vaccination, starting in 2000. We generated stochastic simulations from the fitted parameter sets to evaluate which scenarios could replicate the transmission dynamics observed in vaccinated cases in England. The scenario without waning overestimated the number of one-dose recipients among measles cases, and underestimated the number of two-dose recipients among cases older than 15 years (median 75 cases [95% simulation interval (SI) 44-124] in simulations without waning, 196 [95% SI 122-315] in simulations when waning was included, 188 [95% SI 118-301] in simulations when waning started in 2000, and 202 observed cases). The number of onward transmissions from vaccinated cases was 83% (95% credible interval 72-91%) of the number of transmissions from unvaccinated cases. The estimated waning rate was slow (0·039% per year of age; 95% credible interval 0·034-0·044% per year in the best-fitting scenario with waning starting in 2000), but sufficient to increase measles burden. Measles case dynamics in England are consistent with scenarios assuming the waning of vaccine-induced immunity. Since measles is highly infectious, slow waning leads to a heightened burden in outbreaks, increasing the number of measles cases in people who are both vaccinated and unvaccinated. Our findings show that although the vaccine remains highly protective against measles infections for decades and most transmission is connected to people who are unvaccinated, breakthrough infections are increasingly frequent for individuals aged 15 years and older who have been vaccinated twice. National Institute for Health and Care Research and Wellcome Trust.