Depressive symptoms in women's midlife in relation to their body weight before, during and after childbearing years

OBJECTIVE: This study aimed to examine how weight and weight changes related to pregnancy were associated with depressive symptoms 11–16 years after childbirth. METHOD: We followed 16,998 first‐time mothers from the Danish National Birth Cohort up till 16 years after birth and estimated associations between depressive symptoms and pre‐pregnancy body mass index (BMI) (kg m(−2)), weight changes in different time periods, and BMI‐adjusted waist circumference 7 years after birth (WC(BMI), cm). Depressive symptoms were estimated by the Center for Epidemiologic Studies Depression 10‐item scale. Multiple logistic regression analyses were used to estimate odds ratios (OR) and 95% confidence intervals. RESULTS: Compared with normal‐weight, we found that underweight, overweight and obesity were associated with greater odds of depressive symptoms (1.29, 1.24 and 1.73, respectively). Compared with weight change ±1 BMI unit during the total follow‐up period, greater odds for depressive symptoms were observed with weight loss (OR 1.14, 0.96–1.36) or gain of 2–2.99 kg m(−2) (OR 1.11, 0.92–1.33) or gain of ≥3 kg m(−2) (OR 1.68, 1.46–1.94). WC(BMI) > 2.2 cm was associated with greater odds of depressive symptoms (OR 1.16, 0.99–1.36) than waist circumference as predicted by BMI. CONCLUSION: Low and high pre‐pregnancy BMI, weight changes and WC(BMI) larger than predicted were associated with more depressive symptoms in midlife

Analysis of electron-positron momentum spectra of metallic alloys as supported by first-principles calculations

Electron-positron momentum distributions measured by the coincidence Doppler broadening method can be used in the chemical analysis of the annihilation environment, typically a vacancy-impurity complex in a solid. In the present work, we study possibilities for a quantitative analysis, i.e., for distinguishing the average numbers of different atomic species around the defect. First-principles electronic structure calculations self-consistently determining electron and positron densities and ion positions are performed for vacancy-solute complexes in Al-Cu, Al-Mg-Cu, and Al-Mg-Cu-Ag alloys. The ensuing simulated coincidence Doppler broadening spectra are compared with measured ones for defect identification. A linear fitting procedure, which uses the spectra for positrons trapped at vacancies in pure constituent metals as components, has previously been employed to find the relative percentages of different atomic species around the vacancy [A. Somoza et al. Phys. Rev. B 65, 094107 (2002)]. We test the reliability of the procedure by the help of first-principles results for vacancy-solute complexes and vacancies in constituent metals.Comment: Submitted to Physical Review B on September 19 2006. Revised version submitted on November 8 2006. Published on February 14 200

Gestational age at delivery and special educational need: retrospective cohort study of 407,503 schoolchildren

<STRONG>Background</STRONG> Previous studies have demonstrated an association between preterm delivery and increased risk of special educational need (SEN). The aim of our study was to examine the risk of SEN across the full range of gestation. <STRONG>Methods and Findings</STRONG> We conducted a population-based, retrospective study by linking school census data on the 407,503 eligible school-aged children resident in 19 Scottish Local Authority areas (total population 3.8 million) to their routine birth data. SEN was recorded in 17,784 (4.9%) children; 1,565 (8.4%) of those born preterm and 16,219 (4.7%) of those born at term. The risk of SEN increased across the whole range of gestation from 40 to 24 wk: 37–39 wk adjusted odds ratio (OR) 1.16, 95% confidence interval (CI) 1.12–1.20; 33–36 wk adjusted OR 1.53, 95% CI 1.43–1.63; 28–32 wk adjusted OR 2.66, 95% CI 2.38–2.97; 24–27 wk adjusted OR 6.92, 95% CI 5.58–8.58. There was no interaction between elective versus spontaneous delivery. Overall, gestation at delivery accounted for 10% of the adjusted population attributable fraction of SEN. Because of their high frequency, early term deliveries (37–39 wk) accounted for 5.5% of cases of SEN compared with preterm deliveries (<37 wk), which accounted for only 3.6% of cases. <STRONG>Conclusions</STRONG> Gestation at delivery had a strong, dose-dependent relationship with SEN that was apparent across the whole range of gestation. Because early term delivery is more common than preterm delivery, the former accounts for a higher percentage of SEN cases. Our findings have important implications for clinical practice in relation to the timing of elective delivery