Preterm birth, low birth weight, and infant catch-up growth seem associated with an increased risk of respiratory diseases in later life, but individual studies showed conflicting results. We performed an individual participant data meta-analysis for 147,252 children of 31 birth cohort studies to determine the associations of birth and infant growth characteristics with the risks of preschool wheezing (1-4 years) and school-age asthma (5-10 years). First, we performed an adjusted 1-stage random-effect meta-analysis to assess the combined associations of gestational age, birth weight, and infant weight gain with childhood asthma. Second, we performed an adjusted 2-stage random-effect meta-analysis to assess the associations of preterm birth (gestational age <37 weeks) and low birth weight (<2500 g) with childhood asthma outcomes. Younger gestational age at birth and higher infant weight gain were independently associated with higher risks of preschool wheezing and school-age asthma (P < .05). The inverse associations of birth weight with childhood asthma were explained by gestational age at birth. Compared with term-born children with normal infant weight gain, we observed the highest risks of school-age asthma in children born preterm with high infant weight gain (odds ratio [OR], 4.47; 95% CI, 2.58-7.76). Preterm birth was positively associated with an increased risk of preschool wheezing (pooled odds ratio [pOR], 1.34; 95% CI, 1.25-1.43) and school-age asthma (pOR, 1.40; 95% CI, 1.18-1.67) independent of birth weight. Weaker effect estimates were observed for the associations of low birth weight adjusted for gestational age at birth with preschool wheezing (pOR, 1.10; 95% CI, 1.00-1.21) and school-age asthma (pOR, 1.13; 95% CI, 1.01-1.27). Younger gestational age at birth and higher infant weight gain were associated with childhood asthma outcomes. The associations of lower birth weight with childhood asthma were largely explained by gestational age at birth.

Background A healthy start to life is a major priority in efforts to reduce health inequalities across Europe, with important implications for the health of future generations. There is limited combined evidence on inequalities in health among newborns across a range of European countries. Methods Prospective cohort data of 75 296 newborns from 12 European countries were used. Maternal education, preterm and small for gestational age births were determined at baseline along with covariate data. Regression models were estimated within each cohort and meta-analyses were conducted to compare and measure heterogeneity between cohorts. Results Mother's education was linked to an appreciable risk of preterm and small for gestational age (SGA) births across 12 European countries. The excess risk of preterm births associated with low maternal education was 1.48 (1.29 to 1.69) and 1.84 (0.99 to 2.69) in relative and absolute terms (Relative/Slope Index of Inequality, RII/SII) for all cohorts combined. Similar effects were found for SGA births, but absolute inequalities were greater, with an SII score of 3.64 (1.74 to 5.54). Inequalities at birth were strong in the Netherlands, the UK, Sweden and Spain and marginal in other countries studied. Conclusions This study highlights the value of comparative cohort analysis to better understand the relationship between maternal education and markers of fetal growth in different settings across Europe.

Summary: Background: Nonmalignant portal vein thrombosis is a significant event in the course of cirrhosis that can contraindicate liver transplantation and even impact survival after the surgical procedure. Risk factors are not completely known or validated and are still debated.Aim: To identify in patients with cirrhosis the risk factors for portal vein thrombosis that are assessable in clinical practice.Methods: Between January 2014 and February 2017, 108 outpatients with cirrhosis and no portal vein thrombosis (78% Child A) were enrolled. Doppler ultrasound was performed every 3 or 6 months, for a median follow up of 19 months.Results: Portal vein thrombosis developed in 11 patients. Nonselective beta‐blockade (hazard ratio [HR] 10.56; 95% confidence interval [CI]: 1.35‐82.73; P = 0.025), and medium or large‐sized oesophageal varices (HR 5.67; 95% CI: 1.49‐21.63; P = 0.011) at baseline were associated with portal vein thrombosis development. Although heart rate (P < 0.001) and portal blood flow velocity at baseline (P = 0.005) were significantly reduced by nonselective beta‐blockers, they were not related to portal vein thrombosis development.Conclusions: Our findings confirm an association between portal vein thrombosis development and oesophageal varices at baseline, but suggest that the association could be explained by exposure to nonselective beta‐blockers, independently from effects on heart rate and portal blood flow velocity. The mechanisms that explain portal vein thrombosis development in patients on nonselective beta‐blockers require elucidation in order to optimise targeting of nonselective beta‐blockade in patients with cirrhosis.