Dataset Information

Trends in singleton preterm birth in Victoria, 2007 to 2017: A consecutive cross-sectional study.

ABSTRACT:

Introduction

Preterm birth is a major cause of perinatal morbidity and mortality worldwide. In many countries preterm birth rates are increasing, largely as a result of increases in iatrogenic preterm birth, whereas in other countries rates are stable or even declining. The objective of the study is to describe trends in singleton preterm births in Victoria from 2007 to 2017 in relation to trends in perinatal mortality to identify opportunities for improvements in clinical care.

Material and methods

We conducted a consecutive cross-sectional study in all women with a singleton pregnancy giving birth at ≥20 weeks of pregnancy in Victoria, Australia, between 2007 and 2017, inclusive. Rates of preterm birth and perinatal mortality were calculated and trends were analyzed in all pregnancies, in pregnancies complicated by fetal growth problems, hypertension, (pre)eclampsia or prelabor rupture of membranes (PROM), and in (low-risk) pregnancies not complicated by any of these conditions.

Results

There were 811 534 singleton births between 2007 and 2017. Preterm birth increased from 5.9% (4074 births) to 6.4% (4893 births; P < .001), due to an increase in iatrogenic preterm birth from 2.5% (1730 births) to 3.6% (2730 births; P < .001). Comparable trends were seen in pregnancies complicated by fetal growth problems and hypertension and in pregnancies not complicated by small for gestational age (SGA), hypertension, (pre)eclampsia or PROM (all P < .001). In pregnancies complicated by SGA, hypertension, (pre)eclampsia or PROM the perinatal mortality rate from 20 weeks of gestation fell (13 to 12 per 1000 births; P < .001). In pregnancies not complicated by SGA, hypertension, (pre)eclampsia or PROM there was no significant change in the perinatal mortality from 28 weeks and no decrease in the preterm weekly prospective stillbirth risk.

Conclusions

The singleton preterm birth rate in Victoria is increasing, driven by an increase in iatrogenic preterm birth, both in pregnancies complicated by SGA and hypertension, and in pregnancies not complicated by SGA, hypertension, (pre)eclampsia or PROM. While perinatal mortality decreased in the pregnancies complicated by SGA, hypertension, (pre)eclampsia or PROM, no significant reduction in perinatal mortality from 28 weeks or in preterm weekly prospective stillbirth risk was noted in the pregnancies not complicated by any of these conditions.

SUBMITTER: Burger RJ

PROVIDER: S-EPMC8359202 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:BackgroundTobacco smoking is a leading cause of premature death in China, especially among adult men. Since the implementation of the Framework Convention on Tobacco Control in 2005, nationwide tobacco control has been strengthened, but its long-term impact on smoking prevalence is unclear.Methods and findingsFive nationally representative surveys of the China Chronic Disease and Risk Factor Surveillance (CCDRFS) were conducted in 2007, 2010, 2013, 2015, and 2018. A total of 624,568 adults (278,605 men and 345,963 women) aged 18 to 69 years were randomly selected from 31 provinces (or equivalent) in China. Temporal changes in smoking prevalence and patterns (e.g., percentages of those smoking manufactured cigarettes, amount smoked, and age at smoking initiation) were analyzed, overall and by sex, urban or rural residence, year of birth, education and occupation, using linear regression methods. Among men, the standardized prevalence of current smoking decreased from 58.4% (95% confidence interval [CI]: 56.1 to 60.7) to 50.8% (95% CI: 49.1 to 52.5, p < 0.001) between 2007 and 2018, with annual decrease more pronounced in urban (55.7% [95% CI: 51.2 to 60.3] to 46.3% [95% CI: 43.7 to 49.0], p < 0.001) than rural men (59.9% [95% CI: 57.5 to 62.4] to 54.6% [95% CI: 52.6 to 56.6], p = 0.05) and in those born before than after 1980. Among rural men born after 1990, however, the prevalence increased from 40.2% [95% CI: 34.0 to 46.4] to 52.1% ([95% CI: 45.7 to 58.5], p = 0.007), with the increase taking place mainly before 2015. Among women, smoking prevalence remained extremely low at around 2% during 2007 to 2018. No significant changes of current smoking prevalence (53.9% to 50.8%, p = 0.22) were observed in male patients with at least 1 of major chronic diseases (e.g., hypertension, diabetes, myocardial infarction, stroke, chronic obstructive pulmonary disease (COPD)). In 2018, 25.6% of adults aged ≥18 years smoked, translating into an estimated 282 million smokers (271 million men and 11 million women) in China. Across 31 provinces, smoking prevalence varied greatly. The 3 provinces (Yunnan, Guizhou, and Hunan) with highest per capita tobacco production had highest smoking prevalence in men (68.0%, 63.4%, and 61.5%, respectively), while lowest prevalence was observed in Shanghai (34.8%). Since the children and teenage groups were not included in the surveys, we could not assess the smoking trends among youths. Furthermore, since the smoking behavior was self-reported, the smoking prevalence could be underestimated due to reporting bias.ConclusionsIn this study, we observed that the smoking prevalence has decreased steadily in recent decades in China, but there were diverging trends between urban and rural areas, especially among men born after 1980. Future tobacco control strategies should target rural young men, regions with high tobacco production, and patients suffering from chronic diseases.

Project description:BackgroundBeing exposed to crises during pregnancy can affect maternal health through stress exposure, which can in return impact neonatal health. We investigated temporal trends in neonatal outcomes in Switzerland between 2007 and 2022 and their variations depending on exposure to the economic crisis of 2008, the flu pandemic of 2009, heatwaves (2015 and 2018) and the COVID-19 pandemic.MethodsUsing individual cross-sectional data encompassing all births occurring in Switzerland at the monthly level (2007-2022), we analysed changes in birth weight and in the rates of preterm birth (PTB) and stillbirth through time with generalized additive models. We assessed whether the intensity or length of crisis exposure was associated with variations in these outcomes. Furthermore, we explored effects of exposure depending on trimesters of pregnancy.ResultsOver 1.2 million singleton births were included in our analyses. While birth weight and the rate of stillbirth have remained stable since 2007, the rate of PTB has declined by one percentage point. Exposure to the crises led to different results, but effect sizes were overall small. Exposure to COVID-19, irrespective of the pregnancy trimester, was associated with a higher birth weight (+12 grams [95% confidence interval (CI) 5.5 to 17.9 grams]). Being exposed to COVID-19 during the last trimester was associated with an increased risk of stillbirth (odds ratio 1.24 [95%CI 1.02 to 1.50]). Exposure to the 2008 economic crisis during pregnancy was not associated with any changes in neonatal health outcomes, while heatwave effect was difficult to interpret.ConclusionOverall, maternal and neonatal health demonstrated resilience to the economic crisis and to the COVID-19 pandemic in a high-income country like Switzerland. However, the effect of exposure to the COVID-19 pandemic is dual, and the negative impact of maternal infection on pregnancy is well-documented. Stress exposure and economic constraint may also have had adverse effects among the most vulnerable subgroups of Switzerland. To investigate better the impact of heatwave exposure on neonatal health, weekly or daily-level data is needed, instead of monthly-level data.

Project description:ImportancePreterm birth is a leading cause of preventable neonatal morbidity and mortality. Preterm birth rates at the national level may mask important geographic variation in rates and trends at the county level.ObjectiveTo estimate age-standardized preterm birth rates by US county from 2007 to 2019.Design, setting, and participantsThis serial cross-sectional study used data from the National Center for Health Statistics composed of all live births in the US between 2007 and 2019. Data analyses were performed between March 22, 2022, and September 29, 2022.Main outcomes and measuresAge-standardized preterm birth (<37 weeks' gestation) and secondarily early preterm birth (<34 weeks' gestation) rates by county and year calculated with a validated small area estimation model (hierarchical bayesian spatiotemporal model) and percent change in preterm birth rates using log-linear regression models.ResultsBetween 2007 and 2019, there were 51 044 482 live births in 2383 counties. In 2007, the national age-standardized preterm birth rate was 12.6 (95% CI, 12.6-12.7) per 100 live births. Preterm birth rates varied significantly among counties, with an absolute difference between the 90th and 10th percentile counties of 6.4 (95% CI, 6.2-6.7). The gap between the highest and lowest counties for preterm births was 20.7 per 100 live births in 2007. Several counties in the Southeast consistently had the highest preterm birth rates compared with counties in California and New England, which had the lowest preterm birth rates. Although there was no statistically significant change in preterm birth rates between 2007 and 2019 at the national level (percent change, -5.0%; 95% CI, -10.7% to 0.9%), increases occurred in 15.4% (95% CI, 14.1%-16.9%) of counties. The absolute and relative geographic inequalities were similar across all maternal age groups. Higher quartile of the Social Vulnerability Index was associated with higher preterm birth rates (quartile 4 vs quartile 1 risk ratio, 1.34; 95% CI, 1.31-1.36), which persisted across the study period. Similar patterns were observed for early preterm birth rates.Conclusions and relevanceIn this serial cross-sectional study of county-level preterm and early preterm birth rates, substantial geographic disparities were observed, which were associated with place-based social disadvantage. Stability in aggregated rates of preterm birth at the national level masked increases in nearly 1 in 6 counties between 2007 and 2019.