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Breast milk feeding (BMF) is associated with lower neonatal morbidity in the very preterm infant (<32 weeks gestation) and breastfeeding is beneficial for maternal health. Previous studies show large variations in BMF after very preterm birth and recognize the need for targeted breastfeeding support in the neonatal intensive care units (NICU). In a European collaboration project about evidence-based practices after very preterm birth, we examined the association between maternal, obstetric, and infant clinical factors; neonatal and maternal care unit policies; and BMF at discharge from the NICU. In multivariable analyses, covariates associated with feeding at discharge were first investigated as predictors of any BMF and in further analysis as predictors of exclusive or partial BMF. Overall, 58% (3,826/6,592) of the infants received any BMF at discharge, but there were large variations between regions (range 36-80%). Primiparity, administration of antenatal corticosteroids, first enteral feed <24 hr after birth, and mother's own milk at first enteral feed were predictors positively associated with any BMF at discharge. Vaginal delivery, singleton birth, and receiving mother's own milk at first enteral feed were associated with exclusive BMF at discharge. Units with a Baby Friendly Hospital accreditation improved any BMF at discharge; units with protocols for BMF and units using donor milk had higher rates of exclusive BMF at discharge. This study suggests that there is a high potential for improving BMF through policies and support in the NICU. [ABSTRACT FROM AUTHOR]

Background: Spontaneous closure of patent ductus arteriosus (PDA) occurs frequently in very preterm infants and despite the lack of evidence for treatment benefits, treatment for PDA is common in neonatal medicine. Objectives: The aim of this work was to study regional variations in PDA treatment in very preterm infants (≤ 31 weeks of gestation), its relation to differences in perinatal characteristics, and associations with bronchopulmonary dysplasia (BPD) and survival without major neonatal morbidity. Methods: This was a population-based cohort study in 19 regions in 11 European countries conducted during 2011 and 2012. A total of 6,896 infants with data on PDA treatment were included. The differences in infant characteristics were studied across regions using a propensity score derived from perinatal risk factors for PDA treatment. The primary outcomes were a composite of BPD or death before 36 weeks postmenstrual age, or survival without major neonatal morbidity. Results: The proportion of PDA treatment varied from 10 to 39% between regions (p < 0.001), and this difference could not be explained by differences in perinatal characteristics. The regions were categorized according to a low (<15%, n = 6), medium (15-25%, n = 9), or high (>25%, n = 4) proportion of PDA treatment. Infants treated for PDA, compared to those not treated, were at higher risk of BPD or death in all regions, with an overall propensity score adjusted risk ratio of 1.33 (95% confidence interval 1.18-1.51). Survival without major neonatal morbidity was not related to PDA treatment. Conclusions: PDA treatment varies largely across Europe without associated variations in perinatal characteristics or neonatal outcomes. This finding calls for more uniform guidance for PDA diagnosis and treatment in very preterm infants. [ABSTRACT FROM AUTHOR]

Objective: To determine if maternal use of snuff (containing high levels of nicotine, low levels of nitrosamines and no combustion products) is associated with an increased risk of oral cleft malformations in the infant and whether cessation of snuff use or smoking before the antenatal booking influences the risk. Method: A population-based cohort study was conducted on all live born infants, recorded in the Swedish Medical Birth Register from 1999 through 2009 (n = 1 086 213). Risks of oral clefts were evaluated by multivariate logistic regression analyses (using adjusted odds ratios, with 95% confidence intervals [CI]). Results: Among 975 866 infants that had information on maternal tobacco use, 1761 cases of oral clefts were diagnosed. More than 50% of the mothers who used snuff or smoked three months prior pregnancy stopped using before the antenatal booking. Almost 8% of the mothers were smoking at the antenatal booking and 1,1% of the mothers used snuff. Compared with infants of non-tobacco users, the adjusted odds ratios (95% CI) of any oral cleft for infants of mothers who continued to use snuff or to smoke were 1.48 [1.00–2.21] and 1.19 [1.01–1.41], respectively. In contrast, in infants of mothers who stopped using snuff or stopped smoking before the antenatal booking, the corresponding risks were not increased (adjusted odds ratios [95% CI] were 0.71 [0.44–1.14] and 0.88 [0.73–1.05], respectively). Conclusion: Maternal snuff use or smoking in early pregnancy is associated with an increased risk of oral clefts. Infants of mothers who stopped using snuff or stopped smoking before the antenatal booking had no increased risk of oral cleft malformations. Oral snuff or other sources of nicotine should not be recommended as an alternative for smoke-cessation during pregnancy. [ABSTRACT FROM AUTHOR]

Background: Month of birth – an indicator for a variety of prenatal and early postnatal exposures – has been associated with life expectancy in adulthood. On the northern hemisphere, people born in the autumn live longer than those born during the spring. Only one study has followed a population longitudinally and no study has investigated the relation between month of birth and mortality risk below 50 years. Methods and results: In this nation-wide Swedish study, we included 6,194,745 subjects, using data from population-based health and administrative registries. The relation between month of birth (January – December) and mortality risk was assessed by fitting Cox proportional hazard regression models using attained age as the underlying time scale. Analyses were made for ages >30, >30 to 50, >50 to 80 and >80 years. Month of birth was a significant predictor of mortality in the age-spans >30, >50 to 80, and >80 years. In models adjusted for gender and education for ages >30 and >50 to 80 years, the lowest mortality was seen for people born in November and the highest mortality in those born in the spring/summer, peaking in May for mortality >30 years (25‰ excess hazard ratio compared to November, [95% confidence interval = 16–34 ]) and in April for mortality >50 to 80 years (42‰ excess hazard ratio compared to November, [95% confidence interval = 30–55]). In the ages >80 years the pattern was similar but the differences in mortality between birth months were smaller. For mortality within the age-span >30 to 50 years, results were inconclusive. Conclusion: Month of birth is associated to risk of mortality in ages above 50 years in Sweden. Further studies should aim at clarifying the mechanisms behind this association. [ABSTRACT FROM AUTHOR]

Aim: Preterm transition from foetal to neonatal circulation might permanently alter aortic growth and development. To test this hypothesis, we measured aortic dimensions in adolescents born very preterm. Methods: Eighty-six healthy 15-year-old subjects were studied; 45 born very preterm at an average gestational age of 28 weeks (birth weight < 1500 g) and 41 controls born at term. Using a pulse-gated Fiesta sequence on a 1.5T MR-scanner, 25 images were collected within the heart cycle at several levels of the descending aorta. End-diastolic cross-sectional areas were semi-automatically calculated using an active contour model. Results: Subjects born preterm had narrower aortic lumen. The difference was 16% in the thoracic and 19% in the abdominal aorta after adjustment for body surface area and gender (p < 0.001). Maternal smoking in pregnancy was also found to be an independent risk factor for aortic narrowing in the offspring (difference 10%–13% throughout the aorta vs. offspring to nonsmoking mothers). Adolescents born preterm had higher systolic and diastolic blood pressures; however, blood pressures did not correlate with aortic size or maternal smoking during pregnancy. Conclusion: Very preterm birth and exposure to maternal smoking in foetal life are independent and strong risk factors for general aortic narrowing 15 years after birth. [ABSTRACT FROM AUTHOR]

Aim: Postnatal hypoglycaemia in newborn infants remains an important clinical problem where prolonged periods of hypoglycaemia are associated with poor neurodevelopmental outcome. The aim was to develop an evidence-based national guideline with the purpose to optimise prevention, diagnosis and treatment of hypoglycaemia in newborn infants with a gestational age ≥35 + 0 weeks.Methods: A PubMed search-based literature review was used to find actual and applicable evidence for all incorporated recommendations. The GRADE (Grading of Recommendations, Assessment, Development and Evaluation) approach was used for grading the evidence of the recommendations.Results: Recommendations for the prevention of neonatal hypoglycaemia were extended and updated, focusing on promotion of breastfeeding as one prevention strategy. Oral dextrose gel as a novel supplemental therapy was incorporated in the treatment protocol. A new threshold-based screening and treatment protocol presented as a flow chart was developed.Conclusion: An updated and evidence-based national guideline for screening and treatment of neonatal hypoglycaemia will support standardised regimes, which may prevent hypoglycaemia and the risk for hypoglycaemia-related long-term sequelae. [ABSTRACT FROM AUTHOR]

Comments on the increased risk for cardiovascular disease and stroke associated with low birth weight. Need for further research on the fetal origins of adult diseases; Reference to a study which showed a predisposition for cardiovascular disease among those who were small at birth; Impact of birth weight on the thickness of the aortic wall; Role of aortic wall thickness as an early marker for atherosclerosis; Need for further research on the modifiable causes of dysfunction in fetuses and newborns.

Aim: Using snus, an oral moist tobacco, has increased among pregnant women in Sweden, the only European Union country where sales are legal. This study evaluated whether snus generated similar concentrations of nicotine and its metabolites in breastmilk to cigarette smoking. Methods: We analysed 49 breastmilk samples from 33 nursing mother – 13 snus users, six cigarette smokers and 14 controls – for concentrations of nicotine, cotinine and 3‐hydroxycotinine. The mothers were recruited at antenatal clinics in Sweden from 2007 to 2012. Results: The median nicotine concentration in breastmilk of the snus users was 38.7 ng/mL (0–137) versus 24.0 ng/mL (0–56) in smokers, with median cotinine levels of 327.6 ng/mL (37–958) versus 164.4 ng/mL and median 3‐hydroxycotinine levels of 202.7 ng/mL (28–452) versus 112.4 (0–231), respectively. Nicotine was still detected in the breastmilk of eight of the 13 snus users after abstaining from tobacco for a median duration of 11 hours (0.6–12.5), while the breastmilk of the smokers was nicotine‐free after four hours' abstinence. Conclusion: Snus users had high levels of nicotine and metabolites in their breastmilk and nicotine was found even after 12.5 hours of abstinence. [ABSTRACT FROM AUTHOR]

Aim: Children born very preterm require additional specialist care because of the health and developmental risks associated with preterm birth, but information on their health service use is sparse. We sought to describe the use of specialist services by children born very preterm in Europe.Method: We analysed data from the multi-regional, population-based Effective Perinatal Intensive Care in Europe (EPICE) cohort of births before 32 weeks' gestation in 11 European countries. Perinatal data were abstracted from medical records and parents completed a questionnaire at 2 years corrected age (4322 children; 2026 females, 2296 males; median gestational age 29wks, interquartile range [IQR] 27-31wks; median birthweight 1230g, IQR 970-1511g). We compared parent-reported use of specialist services by country, perinatal risk (based on gestational age, small for gestational age, and neonatal morbidities), maternal education, and birthplace.Results: Seventy-six per cent of the children had consulted at least one specialist, ranging across countries from 53.7% to 100%. Ophthalmologists (53.4%) and physiotherapists (48.0%) were most frequently consulted, but individual specialists varied greatly by country. Perinatal risk was associated with specialist use, but the gradient differed across countries. Children with more educated mothers had higher proportions of specialist use in three countries.Interpretation: Large variations in the use of specialist services across Europe were not explained by perinatal risk and raise questions about the strengths and limits of existing models of care.What This Paper Adds: Use of specialist services by children born very preterm varied across Europe. This variation was observed for types and number of specialists consulted. Perinatal risk was associated with specialist care, but did not explain country-level differences. In some countries, mothers' educational level affected use of specialist services. [ABSTRACT FROM AUTHOR]

Background: Exposure to traffic noise has been associated with hypertension in adults but the evidence in adolescents is limited. We investigated long-term road traffic noise exposure, maternal occupational noise during pregnancy and other factors in relation to blood pressure and prehypertension at 16 years of age.Methods: Systolic and diastolic blood pressure were measured in 2597 adolescents from the Swedish BAMSE birth cohort. Levels of road traffic noise were estimated at home addresses during lifetime and for the mother during pregnancy as well as maternal occupational noise exposure during pregnancy. Exposure to NOx from local sources was also assessed. Associations between noise or NOx exposure and blood pressure or prehypertension were analysed using linear and logistic regression.Results: The prevalence of prehypertension was higher among males and in those with overweight, low physical activity or overweight mothers. No strong or consistent associations were observed between pre- or postnatal exposure to road traffic noise and blood pressure at 16 years of age. However, inverse associations were suggested for systolic or diastolic blood pressure and prehypertension, which reached statistical significance among males (OR 0.80 per 10 dB Lden, 95% CI 0.65-0.99) and those with maternal occupational noise exposure ≥ 70 dB LAeq8h (OR 0.60, 95% CI 0.41-0.87). On the other hand, occupational noise exposure during pregnancy tended to increase systolic blood pressure and prehypertension risk in adolescence. No associations were seen for NOx exposure.Conclusion: No conclusive associations were observed between pre- or postnatal noise exposure and blood pressure or prehypertension in adolescents. [ABSTRACT FROM AUTHOR]

Introduction: Oral moist snuff is widely used in Sweden including during pregnancy. Maternal snuff use has been associated with increased risks of adverse pregnancy outcomes in epidemiological studies. Self-reported maternal snuff use has not been validated previously. The main objective of this study was to validate self-reported snuff use in pregnancy in a prospective cohort study and in the Medical Birth Register.Material and Methods: A prospective Swedish cohort study, 2005-2011, in which 572 women were asked to participate. Of 474 recruited women, 381 non-smokers (263 snuff users and 118 non-tobacco users) were included in the main analyses. Participants prospectively reported snuff use through questionnaires. Medical Birth Register data on the participants was obtained. Maternal urine cotinine was collected in late pregnancy and was used as a biomarker.Results: Cotinine levels in maternal urine confirmed a high validity of self-reported snuff use through questionnaires in late pregnancy; sensitivity and specificity values were 98% and 96%, respectively. In the Medical Birth Register, 45% of the snuff users were misclassified as nonusers in late pregnancy. There were significant differences in median cotinine levels between users of mini pouches and users of standard pouches, but there was a great difference of cotinine levels among users with similar number of pouches used daily.Conclusions: Self-reported snuff use through questionnaires has high validity. In the Medical Birth Register, in late pregnancy, many snuff users were misclassified as nonusers. As a consequence, there is a risk of underestimating the harmful effects of snuff use when using late pregnancy Medical Birth Register data. [ABSTRACT FROM AUTHOR]

Aim: This study investigated the different strategies used in 11 European countries to prevent hypothermia, which continues to affect a large proportion of preterm births in the region.Methods: We examined the association between the reported use of hypothermia prevention strategies in delivery rooms and body temperatures on admission to neonatal intensive care units (NICUs) in 5861 infants born at 22 + 0 to 31 +6 weeks of gestation. The use of plastic bags, wraps, caps, exothermic heat and mattresses was investigated.Results: The proportion of infants born in units that systematically used one or more hypothermia prevention strategies was 88.2% and 50.9% of those infants were hypothermic on admission to NICUs. Of the 9.6% born in units without systematic hypothermia prevention, 73.2% were hypothermic. Only 2.2% of infants were born in units with no reported prevention strategies. Lower gestational age increased the probability of hypothermia. No significant differences were found between the various hypothermia prevention strategies. Hyperthermia was seen in 4.8% of all admitted infants.Conclusion: Very preterm infants had lower risks of hypothermia on NICU admission if the unit used systematic prevention strategies. All the strategies had similar effects, possibly due to implementation rather than a strategy's specific efficacy. [ABSTRACT FROM AUTHOR]

Background: Preterm birth (<37 completed gestational weeks) has been linked to pulmonary hypertension (PH), but the relationship to severity of preterm birth has not been studied. Objectives: We investigated associations between extremely (<28 weeks), very (28–31 weeks), moderately (32–36 weeks) preterm birth, early‐term birth (37–38 weeks) and later PH. Additionally, we explored associations between birthweight for gestational age and PH. Methods: This registry‐based cohort study followed 3.1 million individuals born in Sweden (1987–2016) from 1 up to a maximum of 30 years of age. The outcome was diagnosis or death from PH in national health registers. Adjusted hazard ratios (HR) were estimated using Cox regression analysis. Unadjusted and confounder‐adjusted incidence rate differences were also calculated. Results: Of 3,142,812 individuals, there were 543 cases of PH (1.2 per 100,000 person‐years), 153 of which in individuals without malformations. Compared with individuals born at 39 weeks, adjusted HRs with 95% confidence interval (CI) for PH for extremely, moderately, and very preterm birth were 68.78 (95% CI 49.49, 95.57), 13.86 (95% CI 9.27, 20.72) and 3.42 (95% CI 2.46, 4.74), respectively, and for early‐term birth 1.74 (1.31, 2.32). HRs were higher in subjects without malformations. There were 90 additional cases of PH per 100,000 person‐years in the extremely preterm group (50 after excluding malformations). Very small for gestational age (below 2 SD from estimated birthweight for gestational age and sex) was also associated with increased risk of PH (adjusted HR 2.02, 95% CI 1.14, 3.57). Conclusions: We found an inverse association between gestational age and later PH, but the incidence and absolute risks are low. The severity of preterm birth adds clinically relevant information to the assessment of cardiovascular risks in childhood. [ABSTRACT FROM AUTHOR]

Background: In small clinical studies, preterm birth was associated with altered cardiac structure and increased cardiovascular mortality in the young.Objectives: The goal of this study was to determine the association between preterm birth and risk of incident heart failure (HF) in children and young adults.Methods: This register-based cohort study included 2,665,542 individuals born in Sweden from 1987 to 2012 who were followed up from 1 year of age to December 31, 2013. The main study outcome was diagnosis of HF in the National Patient Register or the Cause of Death Register. The association between preterm birth and risk of incident HF was analyzed by using a Poisson regression model. Estimates were adjusted for maternal and pregnancy characteristics, socioeconomic status, and maternal and paternal cardiovascular disease.Results: During 34.8 million person-years of follow-up (median 13.1 years), there were 501 cases of HF. After exclusion of 52,512 individuals with malformations (n = 196 cases), 305 cases of HF remained (0.88 per 100,000 person-years). Gestational age was inversely associated with the risk of HF. Compared with individuals born at term (≥37 weeks' gestation), adjusted incidence relative risks for HF were 17.0 (95% confidence interval [CI]: 7.96 to 36.3) after extremely preterm birth (<28 weeks) and 3.58 (95% CI: 1.57 to 8.14) after very preterm birth (28 to 31 weeks). There was no risk increase after moderately preterm birth (32 to 36 weeks) (relative risk: 1.36; 95% CI: 0.87 to 2.13).Conclusions: There was a strong association between preterm birth before 32 weeks of gestation and HF in childhood and young adulthood. Although the absolute risk of HF is low in young age, our findings indicate that preterm birth may be a previously unknown risk factor for HF. [ABSTRACT FROM AUTHOR]

BACKGROUND: As a result of antenatal screening, abortion of fetuses with Down syndrome has become increasingly common. Little is known about the cardiovascular phenotype in infants with Down syndrome born today. METHODS: Population-based cohort study based on national health registers including 2588 infants with Down syndrome, live-born in Sweden from 1992 to 2012. Risk ratios for congenital heart defects were calculated per 3-year period, adjusted for maternal age, parity, BMI, smoking, diabetes and hypertensive disease, and infant gender. RESULTS: Any congenital heart defect was diagnosed in 54% of infants with Down syndrome. Overall, year of birth was not associated with risk of any congenital heart defect. However, the risk of complex congenital heart defects decreased over time. Compared with 1992 to 1994, the risk in 2010 to 2012 was reduced by almost 40% (adjusted risk ratio 0.62, 95% confidence interval 0.48-0.79). In contrast, risks for isolated ventricular septal defect (VSD) or atrial septal defect showed significant increases during latter years. Overall, the 3 most common diagnoses were atrioventricular septal defect, VSD, or atrial septal defect, accounting for 42%, 22%, and 16% of congenital heart defects, respectively. Although atrioventricular septal defect was far more common than VSD in 1992 to 1994, they were equally common in 2010 to 2012. CONCLUSIONS: Complex congenital heart defects have become less common in infants diagnosed with Down syndrome. This phenotypic shift could be a result of selective abortion of fetuses with Down syndrome, or due to general improvements in antenatal diagnostics of complex congenital heart defects. [ABSTRACT FROM AUTHOR]

Background: Reproductive factors provide an early window into a woman's coronary heart disease (CHD) risk; however, their contribution to CHD risk stratification is uncertain.Methods and Results: In the Women's Health Initiative Observational Study, we constructed Cox proportional hazards models for CHD including age, pregnancy status, number of live births, age at menarche, menstrual irregularity, age at first birth, stillbirths, miscarriages, infertility ≥1 year, infertility cause, and breastfeeding. We next added each candidate reproductive factor to an established CHD risk factor model. A final model was then constructed with significant reproductive factors added to established CHD risk factors. Improvement in C statistic, net reclassification index (or net reclassification index with risk categories of <5%, 5 to <10%, and ≥10% 10-year risk of CHD), and integrated discriminatory index were assessed. Among 72 982 women (CHD events, n=4607; median follow-up,12.0 [interquartile range, 8.3-13.7] years; mean [standard deviation] age, 63.2 [7.2] years), an age-adjusted reproductive risk factor model had a C statistic of 0.675 for CHD. In a model adjusted for established CHD risk factors, younger age at first birth, number of still births, number of miscarriages, and lack of breastfeeding were positively associated with CHD. Reproductive factors modestly improved model discrimination (C statistic increased from 0.726 to 0.730; integrated discriminatory index, 0.0013; P<0.0001). Net reclassification for women with events was not improved (net reclassification index events, 0.007; P=0.18); and, for women without events, net reclassification was marginally improved (net reclassification index nonevents, 0.002; P=0.04) CONCLUSIONS: Key reproductive factors are associated with CHD independently of established CHD risk factors, very modestly improve model discrimination, and do not materially improve net reclassification. [ABSTRACT FROM AUTHOR]

Importance: Preterm birth is a leading cause of infant mortality, morbidity, and long-term disability, and these risks increase with decreasing gestational age. Obesity increases the risk of preterm delivery, but the associations between overweight and obesity and subtypes of preterm delivery are not clear.Objective: To study the associations between early pregnancy body mass index (BMI) and risk of preterm delivery by gestational age and by precursors of preterm delivery.Design, Setting, and Participants: Population-based cohort study of women with live singleton births in Sweden from 1992 through 2010. Maternal and pregnancy characteristics were obtained from the nationwide Swedish Medical Birth Register.Main Outcomes and Measures: Risks of preterm deliveries (extremely, 22-27 weeks; very, 28-31 weeks; and moderately, 32-36 weeks). These outcomes were further characterized as spontaneous (related to preterm contractions or preterm premature rupture of membranes) and medically indicated preterm delivery (cesarean delivery before onset of labor or induced onset of labor). Risk estimates were adjusted for maternal age, parity, smoking, education, height, mother's country of birth, and year of delivery.Results: Among 1,599,551 deliveries with information on early pregnancy BMI, 3082 were extremely preterm, 6893 were very preterm, and 67,059 were moderately preterm. Risks of extremely, very, and moderately preterm deliveries increased with BMI and the overweight and obesity-related risks were highest for extremely preterm delivery. Among normal-weight women (BMI 18.5-<25), the rate of extremely preterm delivery was 0.17%. As compared with normal-weight women, rates (%) and adjusted odds ratios (ORs [95% CIs]) of extremely preterm delivery were as follows: BMI 25 to less than 30 (0.21%; OR, 1.26; 95% CI, 1.15-1.37), BMI 30 to less than 35 (0.27%; OR, 1.58; 95% CI, 1.39-1.79), BMI 35 to less than 40 (0.35%; OR, 2.01; 95% CI, 1.66-2.45), and BMI of 40 or greater (0.52%; OR, 2.99; 95% CI, 2.28-3.92). Risk of spontaneous extremely preterm delivery increased with BMI among obese women (BMI≥30). Risks of medically indicated preterm deliveries increased with BMI among overweight and obese women.Conclusions and Relevance: In Sweden, maternal overweight and obesity during pregnancy were associated with increased risks of preterm delivery, especially extremely preterm delivery. These associations should be assessed in other populations. [ABSTRACT FROM AUTHOR]

Importance Preterm birth is a leading cause of infant mortality, morbidity, and long-term disability, and these risks increase with decreasing gestational age. Obesity in-creases the risk of preterm delivery, but the associations between overweight and obe-sity and subtypes of preterm delivery are not clear. Objective To study the associations between early pregnancy body mass index (BMI) and risk of preterm delivery by gestational age and by precursors of preterm delivery. Design, Setting, and Participants Population-based cohort study of women with live singleton births in Sweden from 1992 through 2010. Maternal and pregnancy char-acteristics were obtained from the nationwide Swedish Medical Birth Register. Main Outcomes and Measures Risks of preterm deliveries (extremely, 22-27 weeks; very, 28-31 weeks; and moderately, 32-36 weeks). These outcomes were further char-acterized as spontaneous (related to preterm contractions or preterm premature rup-ture of membranes) and medically indicated preterm delivery (cesarean delivery be-fore onset of labor or induced onset of labor). Risk estimates were adjusted for maternal age, parity, smoking, education, height, mother's country of birth, and year of delivery. Results Among 1 599 551 deliveries with information on early pregnancy BMI, 3082 were extremely preterm, 6893 were very preterm, and 67 059 were moderately pre-term. Risks of extremely, very, and moderately preterm deliveries increased with BMI and the overweight and obesity-related risks were highest for extremely preterm de-livery. Among normal-weight women (BM118.5-<25), the rate of extremely preterm delivery was 0.17%. As compared with normal-weight women, rates (%) and ad-justed odds ratios (ORs [95% CIs]) of extremely preterm delivery were as follows: BMI 25 to less than 30 (0.21%; OR, 1.26; 95% CI, 1.15-1.37), BMI 30 to less than 35 (0.27%; OR, 1.58; 95% CI, 1.39-1.79), BMI 35 to less than 40 (0.35%; OR, 2.01; 95% CI, 1.66-2.45), and BMI of 40 or greater (0.52%; OR, 2.99; 95% CI, 2.28-3.92). Risk of spontaneous extremely preterm delivery increased with BMI among obese women (BMIa30). Risks of medically indicated preterm deliveries increased with BMI among overweight and obese women. Conclusions and Relevance In Sweden, maternal overweight and obesity during pregnancy were associated with increased risks of preterm delivery, especially ex-tremely preterm delivery. These associations should be assessed in other populations. [ABSTRACT FROM AUTHOR]

The aim was to investigate the association of gestational age (GA), echocardiographic markers and levels of plasma N-terminal pro-B-type natriuretic peptide (NTproBNP) with the closure rate of a haemodynamically significant patent ductus arteriosus (hsPDA). Ninety-eight Swedish extremely preterm infants, mean GA 25.7 weeks (standard deviation 1.3), born in 2012–2014, were assessed with echocardiography and for levels of NTproBNP. Thirty-three (34%) infants had spontaneous ductal closure within three weeks of age. Infants having spontaneous closure at seven days or less had significantly lower NTproBNP levels on day three, median 1810 ng/L (IQR 1760–6000 ng/L) compared with: infants closing spontaneously later, 10,900 ng/L (6120–19,200 ng/L); infants treated either with ibuprofen only, 14,600 ng/L (7740–28,100 ng/L); or surgery, 32,300 ng/L (29,100–35,000 ng/L). Infants receiving PDA surgery later had significantly higher NTproBNP values on day three than other infants. Day three NTproBNP cut-off values of 15,001–18,000 ng/L, predicted later PDA surgery, with an area under the curve in ROC analysis of 0.69 (0.54–0.83). In conclusion, the spontaneous PDA closure rate is relatively high in extremely preterm infants. Early NTproBNP levels can be used with GA in the management decisions of hsPDA. [ABSTRACT FROM AUTHOR]

Aim: Using snus, an oral moist tobacco, has increased among pregnant women in Sweden, the only European Union country where sales are legal. This study evaluated whether snus generated similar concentrations of nicotine and its metabolites in breastmilk to cigarette smoking.Methods: We analysed 49 breastmilk samples from 33 nursing mother - 13 snus users, six cigarette smokers and 14 controls - for concentrations of nicotine, cotinine and 3-hydroxycotinine. The mothers were recruited at antenatal clinics in Sweden from 2007 to 2012.Results: The median nicotine concentration in breastmilk of the snus users was 38.7 ng/mL (0-137) versus 24.0 ng/mL (0-56) in smokers, with median cotinine levels of 327.6 ng/mL (37-958) versus 164.4 ng/mL and median 3-hydroxycotinine levels of 202.7 ng/mL (28-452) versus 112.4 (0-231), respectively. Nicotine was still detected in the breastmilk of eight of the 13 snus users after abstaining from tobacco for a median duration of 11 hours (0.6-12.5), while the breastmilk of the smokers was nicotine-free after four hours' abstinence.Conclusion: Snus users had high levels of nicotine and metabolites in their breastmilk and nicotine was found even after 12.5 hours of abstinence. [ABSTRACT FROM AUTHOR]