Deconstructing the smoking-preeclampsia paradox through a counterfactual framework.

Although smoking during pregnancy may lead to many adverse outcomes, numerous studies have reported a paradoxical inverse association between maternal cigarette smoking during pregnancy and preeclampsia. Using a counterfactual framework we aimed to explore the structure of this paradox as being a consequence of selection bias. Using a case-control study nested in the Icelandic Birth Registry (1309 women), we show how this selection bias can be explored and corrected for. Cases were defined as any case of pregnancy induced hypertension or preeclampsia occurring after 20 weeks' gestation and controls as normotensive mothers who gave birth in the same year. First, we used directed acyclic graphs to illustrate the common bias structure. Second, we used classical logistic regression and mediation analytic methods for dichotomous outcomes to explore the structure of the bias. Lastly, we performed both deterministic and probabilistic sensitivity analysis to estimate the amount of bias due to an uncontrolled confounder and corrected for it. The biased effect of smoking was estimated to reduce the odds of preeclampsia by 28 % (OR 0.72, 95 %CI 0.52, 0.99) and after stratification by gestational age at delivery ( 1, revealing the structure of the paradox. The bias-adjusted estimation of the smoking effect on preeclampsia showed an OR of 1.22 (95 %CI 0.41, 6.53). The smoking-preeclampsia paradox appears to be an example of (1) selection bias most likely caused by studying cases prevalent at birth rather than all incident cases from conception in a pregnancy cohort, (2) omitting important confounders associated with both smoking and preeclampsia (preventing the outcome to develop) and (3) controlling for a collider (gestation weeks at delivery). Future studies need to consider these aspects when studying and interpreting the association between smoking and pregnancy outcomes

Sleep-Disordered Breathing and Gestational Diabetes Mellitus: A meta-analysis of 9,795 participants enrolled in epidemiological observational studies

OBJECTIVE Recently, sleep-disordered breathing (SDB) has been reported to be associated with the development of gestational diabetes mellitus (GDM). Accordingly, as this is emergent area of research that has significant clinical relevance, the objective of this meta-analysis is to examine the relationship between SDB with GDM. RESEARCH DESIGN AND METHODS We searched several electronic databases for all of the studies published before January 2013 and reviewed references of published articles. Meta-analytic procedures were used to estimate the unadjusted and BMI-adjusted odds ratios (ORs) using a random effects model. Significant values, weighted effect sizes, and 95% CIs were calculated, and tests of homogeneity of variance were performed. RESULTS Results from nine independent studies with a total of 9,795 pregnant women showed that SDB was significantly associated with an increased risk of GDM. Women with SDB had a more than threefold increased risk of GDM, with a pooled BMI-adjusted OR 3.06 (95% CI 1.89–4.96). CONCLUSIONS These findings demonstrate a significant association between SDB and GDM that is evident even after considered confounding by obesity. This meta-analysis indicates a need to evaluate the role of early recognition and treatment of SDB early during pregnancy

Molluscs from deep bioclastic gravel bottoms of the Alborán Island (LIFE+ INDEMARES Project)

Resumen de posterDurante el proyecto LIFE+ INDEMARES Alborán (2011-2013), se tomaron diez muestras mediante arte de arrastre (bou de vara) en los fondos de cascajo profundo que aparecen entre 80 y 200 m en la plataforma insular de la isla de Alborán. Estos fondos están formados por restos calcáreos biógenos (bioclastos). En las muestras se han encontrado un total de 2.713 ejemplares vivos de moluscos pertenecientes a 147 especies (2 solenogastros, 2 poliplacóforos, 97 gasterópodos, 45 bivalvos, 1 cefalópodo). Los muestreos realizados han puesto de manifiesto la presencia de una alta riqueza de especies de invertebrados. En el caso de los moluscos, la riqueza específica de las muestras fue alta (entre 24 y 55 especies), mientras que las abundancias fueron entre moderadas y altas (entre 154 y 846 individuos), oscilando la diversidad de Shannon-Wiener (H’) entre 2,20 y 3,30. En las muestras estudiadas destaca la presencia de pocas especies comunes y de un elevado número de especies raras. Estas últimas pueden ser accidentales en estos fondos y comunes en otros hábitats próximos, pero otras, como Rugulina monterosatoi Aartsen y Bogi, 1987, Epitonium linctum (de Boury y Monterosato, 1890), Epitonium pseudonanum Bouchet y Warén, 1986, Strobiligera flammulata Bouchet y Warén, 1993, Cerithiopsis atalaya Watson, 1885, Cerithiopsis nofronii Amati, 1987 y Pseudobabylonella minima (Reeve, 1856), se consideran raras ya que no son frecuentes en ningún otro hábitat. La mayoría de las especies de moluscos encontradas en los fondos de cascajo de la isla de Alborán tienen una distribución atlántico-mediterránea, y están presentes normalmente en el Mediterráneo y en el Atlántico ibero-marroquí o más allá de esta zona. Se han encontrado dos especies de afinidad biogeográfica subtropical (costa occidental africana), cuya presencia es uno de los rasgos característicos del mar de Alborán: Mitrella pallaryi (Dautzenberg, 1891) y Nassarius denticulatus (A. Adams, 1852). Además, se ha recolectado viva una especie de reciente descripción, Trophonopsis alboranensis (Smriglio, Mariottini y Bonfitto, 1997), probablemente endémica de esta zona al no haberse encontrado fuera de la isla de Alborán. Los gasterópodos Anatoma aspera (Philippi, 1844), Xenophora crispa (König, 1825), Schilderia achatidea (Gray en G. B. Sowerby I, 1837), Trophonopsis alboranensis y Fusiturris similis (Bivona Ant. en Bivona And., 1838), así como los bivalvos Bathyarca pectunculoides (Scacchi, 1834), Similipecten similis (Laskey, 1811) y Parvamussium fenestratum (Forbes, 1844), entre otras especies, caracterizan el cascajo profundo en la plataforma de Alborán, y lo diferencian de los fondos coralígenos o de “maërl” adyacentes. Por su elevada diversidad y por ser un hábitat esencial para varias especies vulnerables (no sólo de moluscos), consideramos que los fondos de cascajo profundo deben ser incluidos en el Anexo I (Hábitats naturales de interés comunitario cuya conservación requiere la designación de zonas de especial conservación) de la Directiva 92/43/CEE de Hábitats, para lo cual se ha elaborado la correspondiente propuesta en el marco del proyecto LIFE+ INDEMARES.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Ternary hydrotalcites in the multicomponent synthesis of 4H-pyrans

Lamellar double hydroxides (LDH) with double divalent cations were synthesized by the co-precipitation method and studied in the multicomponent synthesis of 4H-pyrans. The solids obtained were characterized by X-ray diffraction (XRD), infrared spectroscopy (FTIR), N2 adsorption isotherms, and thermogravimetric analysis (TGA). The XRD patterns confirmed the formation of LDHs in which the incorporation of Ni2+ or Co2+ improves their crystalline and textural properties. The results of catalytic activity showed that the synthesis of 4H-pyrans is favored in solvent-free conditions with the LDH–Ni catalyst, avoiding calcination processes. In addition, it was found that hydrotalcite with double divalent cations can conduct this reaction through multicomponent synthesis or by the Michael addition reaction, which can be performed by different types of basicity that depend on the composition of another divalent cation in the brucite layer or a calcination process.Fil: Nope Vargas, Eliana Rocio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; ArgentinaFil: Sathicq, Angel Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; ArgentinaFil: Martínez, José J.. Universidad Pedagógica y Tecnológica de Colombia; ColombiaFil: Rojas, Hugo A.. Universidad Pedagógica y Tecnológica de Colombia; ColombiaFil: Luque, Rafael. Universidad de Córdoba; EspañaFil: Romanelli, Gustavo Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; Argentin

Ternary hydrotalcites in the multicomponent synthesis of 4H-pyrans

Lamellar double hydroxides (LDH) with double divalent cations were synthesized by the co-precipitation method and studied in the multicomponent synthesis of 4H-pyrans. The solids obtained were characterized by X-ray diffraction (XRD), infrared spectroscopy (FTIR), N2 adsorption isotherms, and thermogravimetric analysis (TGA). The XRD patterns confirmed the formation of LDHs in which the incorporation of Ni2+ or Co2+ improves their crystalline and textural properties. The results of catalytic activity showed that the synthesis of 4H-pyrans is favored in solvent-free conditions with the LDH–Ni catalyst, avoiding calcination processes. In addition, it was found that hydrotalcite with double divalent cations can conduct this reaction through multicomponent synthesis or by the Michael addition reaction, which can be performed by different types of basicity that depend on the composition of another divalent cation in the brucite layer or a calcination process.Fil: Nope Vargas, Eliana Rocio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; ArgentinaFil: Sathicq, Angel Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; ArgentinaFil: Martínez, José J.. Universidad Pedagógica y Tecnológica de Colombia; ColombiaFil: Rojas, Hugo A.. Universidad Pedagógica y Tecnológica de Colombia; ColombiaFil: Luque, Rafael. Universidad de Córdoba; EspañaFil: Romanelli, Gustavo Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; Argentin

Secular trends in stillbirth by maternal socioeconomic status in Spain 2007–15: a population-based study of 4 million births

Stillbirth, one of the urgent concerns of preventable perinatal deaths, has wide-reaching consequences for society. We studied secular stillbirth trends by maternal socioeconomic status (SES) in Spain.We developed a population-based observational study, including 4 083 919 births during 2007–15. We estimate stillbirth rates and secular trends by maternal SES. We also evaluated the joint effect of maternal educational attainment and the Human Development Index (HDI) of women’s country of origin on the risk of stillbirth. The data and statistical analysis can be accessed for reproducibility in a GitHub repository: https://github.com/migariane/StillbirthWe found a consistent pattern of socioeconomic inequalities in the risk of delivering a stillborn, mainly characterized by a persistently higher risk, over time, among women with lower SES. Overall, women from countries with low HDIs and low educational attainments had approximately a four times higher risk of stillbirth (RR: 4.44; 95%CI: 3.71–5.32). Furthermore, we found a paradoxical reduction of the stillbirth gap over time between the highest and the lowest SESs, which is mostly due to the significant and increasing trend of stillbirth risk among highly educated women of advanced maternal age.Our findings highlight no improvement in stillbirth rates among women of lower SES and an increasing trend among highly educated women of advanced maternal age over recent years. Public health policies developing preventive programmes to reduce stillbirth rates among women with lower SES are needed as well as the necessity of further study to understand the growing trend of age-related stillbirths among highly educated women in Spain

Prevalence and risk factors of gestational diabetes mellitus: findings from a universal screening feasibility program in Lima, Peru.

BACKGROUND: Gestational diabetes mellitus (GDM) is a global public health concern with potential implications for the health of a mother and her offspring. However, data on the prevalence and risk factors of GDM in Latin America are scarce. The study was designed to estimate the prevalence of GDM and identify maternal risk factors among Peruvian women. METHODS: A cross-sectional study was conducted among 1300 pregnant women attending a prenatal clinic in Lima, Peru. GDM was diagnosed using an Oral Glucose Tolerance Test (OGTT) performed between 24 and 28 gestational weeks using the International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria. Depression status was assessed using the Patient Health Questionnaire-9. Multivariate logistic regression models were used to identify risk factors of GDM. RESULTS: Approximately 16% of pregnant women were diagnosed with GDM. The prevalence of obesity and depression were 24.4 and 10.6%, respectively. After adjusting for confounders, mid-pregnancy obesity was associated with a 1.64-fold increased odds of GDM (OR: 1.64; 95% CI: 1.03-2.61). Participants with a family history of diabetes had a 1.5-fold increased odds of developing GDM (OR: 1.51, 95% CI: 1.10-2.07) as compared to women without this family history. Depression was associated with a 1.54-fold increased odds of GDM (OR: 1.54; 95% CI:1.09-2.17). CONCLUSIONS: GDM is highly prevalent and was associated with maternal obesity, family history of diabetes and antepartum depression among Peruvian women. Intervention programs aimed at early diagnoses and management of GDM need to take maternal obesity, family history of diabetes and antepartum depression into account

The Role of Early Pregnancy Maternal pGCD59 Levels in Predicting Neonatal Hypoglycemia-Subanalysis of the DALI Study

CONTEXT: Neonatal hypoglycaemia (NH) is the most common metabolic problem in infants born of mothers with gestational diabetes. Plasma glycated CD59 (pGCD59) is an emerging biomarker that has shown potential in identifying women at risk of developing gestational diabetes. The aim of this study was to assess the association between early maternal levels of pGCD59 and NH. OBJECTIVE: The aim of this study was to assess the association between early pregnancy maternal levels of plasma glycated CD59 (pGCD59) and neonatal hypoglycemia (NH). METHODS: This is an observational study of pregnant women with a prepregnancy body mass index (BMI) greater than or equal to 29 screened for eligibility to participate in the Vitamin D and Lifestyle Intervention for Gestational Diabetes (DALI) trial. This analysis included 399 pregnancies. Levels of pGCD59 were measured in fasting maternal samples taken at the time of a 75-g, 2-hour oral glucose tolerance test performed in early pregnancy (< 20 weeks). NH, the study outcome, was defined as a heel-prick capillary glucose level of less than 2.6 mmol/L within 48 hours of delivery. RESULTS: We identified 30 infants with NH. Maternal levels of pGCD59 in early pregnancy were positively associated with the prevalence of NH (one-way analysis of variance, P < .001). The odds of NH were higher in infants from mothers in tertile 3 of pGCD59 levels compared to those from mothers in tertile 1 (odds ratio [OR]: 2.41; 95% CI, 1.03-5.63). However, this was attenuated when adjusted for maternal BMI (OR: 2.28; 95% CI, 0.96-5.43). The cross-validated area under the curve (AUC) was 0.64 (95% CI, 0.54-0.74), and adjusted for maternal BMI, age, and ethnicity, the AUC was 0.70 (95% CI, 0.56-0.78). CONCLUSION: Although pGCD59 levels in early pregnancy in women with BMI greater than or equal to 29 are associated with NH, our results indicate that this biomarker by itself is only a fair predictor of NH