Chorioamnionitis and cerebral palsy in term and near-term infants

The following abstracts of articles from leading journals have been selected on the basis of their importance to the practice of obstetrics and gynecology. Association between estrogen receptor alpha gene variation and cardiovascular disease CONTEXT: Estrogen and related hormone therapies activate estrogen receptors, which in turn regulate genes for several cardiovascular disease (CVD) risk factors. Relatively little is known, however, about the impact of genetic variation in estrogen receptor alpha (ESR1) on CVD risk. OBJECTIVE: To investigate whether the ESR1 c.454-397T C polymorphism is associated with CVD risk. DESIGN, SETTING, AND PARTICIPANTS: Prospective study of 1,739 unrelated men and women from the population-based offspring cohort of the Framingham Heart Study, who were followed up from 1971 to 1998. MAIN OUTCOME MEASURES: Total atherosclerotic CVD events, defined as recognized or unrecognized myocardial infarction (MI), angina pectoris, coronary insufficiency, intermittent claudication, coronary heart disease death, or atherothrombotic stroke (n 178); major atherosclerotic CVD, defined as recognized acute MI, coronary insufficiency, coronary heart disease death, or atherothrombotic stroke (n 83); and recognized acute MI (n 59). RESULTS: Twenty percent of participants (n 352) were homozygous for the ESR1 c.454-397C allele. After adjustment for covariates (age, sex, body mass index, hypertension, diabetes mellitus, total cholesterol, high-density lipoprotein cholesterol, and cigarette smoking), the CC genotype was significantly associated with major atherosclerotic CVD, with an odds ratio of 2.0 (95% confidence interval 1.3, 3.2; P .004) compared with individuals with the CT or TT genotypes. Participants with the CC genotype had 3.0-fold greater odds of MI (95% confidence interval 1.7, 5.2; P .001) compared with those with the CT or TT genotype. The results remained significant when analyses were restricted to men; too few women had events to study them separately. CONCLUSIONS: Individuals with the common ESR1 c.454397CC genotype have a substantial increase in risk of MI. Whether ESR1 c.454-397T C is causally related to MI risk or in linkage disequilibrium with 1 or more causal variants remains to be determined. These findings support the importance of estrogen receptors in CVD susceptibility, especially in men. Estrogen receptor variation also has potential to explain recent conflicting data regarding the effects of hormone therapy on CVD susceptibility in women. Shearman AM, Cupples LA, Demissie S, Peter I, Schmid CH, Karas RH, Mendelsohn ME, Housman DE, and Levy D. JAMA 2003;290:2263–70. (http://jama.ama-assn.org) Deep vein thrombosis and air travel: record linkage study OBJECTIVE: To investigate the time relations between long haul air travel and venous thromboembolism. DESIGN: Record linkage study using the case crossover approach. SETTING: Western Australia. PARTICIPANTS: Five thousand four hundred eight patients admitted to hospital with venous thromboembolism and matched with data for arrivals of international flights during 1981–99. RESULTS: The risk of venous thromboembolism is increased for only 2 weeks after a long-haul flight; 46 Australian citizens and 200 non-Australian citizens had an episode of venous thromboembolism during this so-called hazard period. The relative risk during this period for Australian citizens was 4.17 (95% confidence interval 2.94, 5.40), with 76% of cases (n 35) attributable to the preceding flight. A “healthy traveler” effect was observed, particularly for Australian citizens. CONCLUSIONS: The annual risk of venous thromboembolism is increased by 12% if one long-haul flight is taken yearly. The average risk of death from flight related venous thromboembolism is small compared with that from motor vehicle crashes and injuries at work. The individual risk of death from flight related venous thromboembolism for people with certain preexisting medical conditions is, however, likely to be greater than the average risk of 1 per 2 million for passengers arriving from a flight. Airlines and health authorities should continue to advise passengers on how to minimize risk. Kelman CW, Kortt MA, Becker NG, Li Z, Mathews JD, Guest CS, Holman CD. BMJ 2003;327:1072.