Risk of miscarriage after chorionic villus sampling.

OBJECTIVE: To estimate the risk of miscarriage associated to chorionic villus sampling (CVS). METHODS: This was a retrospective cohort study performed in eight fetal-medicine units in Spain, Belgium and Bulgaria. Two populations were included: first, all singleton pregnancies attending to their first-trimester assessment in Murcia, Spain, and second, all singleton pregnancies having a CVS following first-trimester assessment at any of the participating centers. We used propensity score matching analysis to estimate the association between CVS and miscarriage. We compared risks of miscarriage of CVS and non-CVS groups after propensity score matching (1:1 ratio). This procedure creates two comparable groups balancing the maternal and pregnancy characteristics that lead to CVS, in a similar way in which randomization operates in a randomized clinical trial. RESULTS: The study population consisted of 22,250 participants in the non-CVS group and 3,613 in the CVS group. The incidence of miscarriage in the CVS group was 2.1% (77/3,613), which was significantly higher than the 0.9% (207/22,250) in the non-CVS group (p <0.001). The propensity score algorithm matched 2,122 CVS cases with 2,122 non-CVS cases including 40 (1.9%) and 55 (2.6%) miscarriages in the CVS and non-CVS groups, respectively (OR 0.72 [95% CI 0.48 to 1.10]; p = 0.146). However, we found a significant interaction between the CVS risk of miscarriage and the risk of aneuploidies, suggesting a different effect of the CVS for different baseline characteristics in such a way that, when the risk of aneuploidies is low, the risk after CVS increases (OR 2.87 [95% CI 1.13 to 7.30]) but when the risk is high, the risk after CVS is paradoxically reduced (OR 0.47 [95% CI 0.28 to 0.76]), presumably due to prenatal diagnosis and termination of major aneuploidies that would have otherwise resulted in spontaneous miscarriage. CONCLUSIONS: The risk of miscarriage in women having a CVS is about 1% higher than in women without CVS, although this excess risk is not entirely due to the invasive procedure but to some extent the demographic and pregnancy characteristics of the patient undergoing CVS. After accounting for these risk factors and confining the analysis to low-risk pregnancies, CVS seems to increase the risk of miscarriage about three times above the patient's background-risk. Although this is a substantial increase in relative terms, in pregnancies without risk factors, the risk of miscarriage after CVS will still remain low and similar to or slightly higher than that of the general population. For example, if her risk of aneuploidy is 1 in a 1,000 (0.1%), her risk of miscarriage after CVS will increase to 0.3% (0.2% higher)

1019-Pentane measurement in man as an index of lipoperoxidation

The peroxidation of unsaturated fatty acids, constituents of tissues, is one proposed mechanism of invivo oxidant damage. Several methods are described to quantify in vivo lipid peroxidation: malonaldehyde determination, measurement of conjugated dienes and the detection of volatile products in expired gases. The measurement of expired volatile hydrocarbons is a specific and non-invasive technique for monitoring in vivo lipid peroxidation. We describe here an improved method for detecting and quantifying volatile products of lipid peroxidation in the breath of healthy human volunteers. We also include a discussion of the obtained results and of the advantages and disadvantages of measuring expired hydrocarbon gases. © 1987.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Ice caves as an indicator of winter climate evolution: a case study from the Jura Mountains

Subsurface ice fillings were first described in the Jura Mountains at the end of the sixteenth century. In order to assess the impact of climate change on low-altitude cave ice a detailed inventory has been drawn up and more than 50 objects have been identified. Comparisons between older cave maps, photographic documents and present-day observations outline a negative trend in ice mass balances, a trend that increased at the end of the 1980s. As most of these ice caves act as cold air traps, this negative mass balance is mainly attributed to higher winter temperatures and to reduced snow precipitation at low altitudes. The equilibrium line altitude of ice caves is believed to have increased several hundred metres between AD 1978 and 2004. Photographic comparisons and proxy records in some of the caves studied provide evidence of a rapid mass turnover. Ice ages range between less than a few decades and a millennium. Climatic records in these ice fillings will therefore present only short time series compared with other cave sediments. However, indications of former ice fillings have been found in different caves of the Jura Mountains and outline their potential role as palaeoclimatic markers