Longitudinal study to assess changes in arterial stiffness and cardiac output parameters among low-risk pregnant women.

AIM: A single-centre, prospective longitudinal study to assess changes in maternal arterial stiffness and cardiac output parameters among low-risk healthy pregnant women. METHODOLOGY: Thirty low-risk, healthy, pregnant women attending their routine antenatal dating ultrasound scan were recruited. Non-invasive assessment of arterial stiffness and cardiac output was undertaken at five gestational windows from 11 to 40 weeks of pregnancy. Data were analysed using a linear mixed model incorporating time and other relevant predictors as fixed effects, and patient as a random effect. RESULTS: Gestational age had a significant effect on all arterial stiffness parameters, including brachial augmentation index (AIx) (p = .001), aortic AIx (p = .002) and aortic pulse wave velocity (p = .002). The aortic AIx (%) reduced during pregnancy: the lowest mean (standard error, SE) was 4.07 (1.01) at 28 weeks before it increased to 7.04 (SE 1.64) at 40 weeks. Similarly, non-invasive assessments of cardiac output (p < .001), stroke volume (p = .014), heart rate (p < .001) and total peripheral resistance (p < .001) demonstrated significant changes with gestational age. Mean cardiac output (l/m) increased during pregnancy reaching a peak at 28 weeks gestation 6.66 (SE 0.28), but dropped thereafter to reach 5.71 (SE 0.25) around term. CONCLUSION: The current study provides pregnancy normograms for gestational changes in arterial stiffness and cardiac output parameters among low-risk, healthy pregnant women. Further work will be required to assess the risk of placental mediated diseases and pregnancy outcome among pregnant women with parameters outside the normal range

Influence of antenatal physical exercise on haemodynamics in pregnant women: a flexible randomisation approach

Background: Normal pregnancy is associated with marked changes in haemodynamic function, however theinfluence and potential benefits of antenatal physical exercise at different stages of pregnancy and postpartumremain unclear. The aim of this study was therefore to characterise the influence of regular physical exercise onhaemodynamic variables at different stages of pregnancy and also in the postpartum period.Methods: Fifty healthy pregnant women were recruited and randomly assigned (2 × 2 × 2 design) to a land orwater-based exercise group or a control group. Exercising groups attended weekly classes from the 20th week ofpregnancy onwards. Haemodynamic assessments (heart rate, cardiac output, stroke volume, total peripheralresistance, systolic and diastolic blood pressure and end diastolic index) were performed using the Task Forcehaemodynamic monitor at 12–16, 26–28, 34–36 and 12 weeks following birth, during a protocol including posturalmanoeurvres (supine and standing) and light exercise.Results: In response to an acute bout of exercise in the postpartum period, stroke volume and end diastolic indexwere greater in the exercise group than the non-exercising control group (p = 0.041 and p = 0.028 respectively).Total peripheral resistance and diastolic blood pressure were also lower (p = 0.015 and p = 0.007, respectively) in theexercise group. Diastolic blood pressure was lower in the exercise group during the second trimester (p = 0.030).Conclusions: Antenatal exercise does not appear to substantially alter maternal physiology with advancinggestation, speculating that the already vast changes in maternal physiology mask the influences of antenatalexercise, however it does appear to result in an improvement in a woman’s haemodynamic function (enhancedventricular ejection performance and reduced blood pressure) following the end of pregnancy

Behavioral genetics and taste

This review focuses on behavioral genetic studies of sweet, umami, bitter and salt taste responses in mammals. Studies involving mouse inbred strain comparisons and genetic analyses, and their impact on elucidation of taste receptors and transduction mechanisms are discussed. Finally, the effect of genetic variation in taste responsiveness on complex traits such as drug intake is considered. Recent advances in development of genomic resources make behavioral genetics a powerful approach for understanding mechanisms of taste

Serum screening with Down's syndrome markers to predict pre-eclampsia and small for gestational age: Systematic review and meta-analysis

<p>Abstract</p> <p>Background</p> <p>Reliable antenatal identification of pre-eclampsia and small for gestational age is crucial to judicious allocation of monitoring resources and use of preventative treatment with the prospect of improving maternal/perinatal outcome. The purpose of this systematic review was to determine the accuracy of five serum analytes used in Down's serum screening for prediction of pre-eclampsia and/or small for gestational age.</p> <p>Methods</p> <p>The data sources included Medline, Embase, Cochrane library, Medion (inception to February 2007), hand searching of relevant journals, reference list checking of included articles, contact with experts. Two reviewers independently selected the articles in which the accuracy of an analyte used in Downs's serum screening before the 25^thgestational week was associated with the occurrence of pre-eclampsia and/or small for gestational age without language restrictions. Two authors independently extracted data on study characteristics, quality and results.</p> <p>Results</p> <p>Five serum screening markers were evaluated. 44 studies, testing 169,637 pregnant women (4376 pre-eclampsia cases) and 86 studies, testing 382,005 women (20,339 fetal growth restriction cases) met the selection criteria. The results showed low predictive accuracy overall. For pre-eclampsia the best predictor was inhibin A>2.79MoM positive likelihood ratio 19.52 (8.33,45.79) and negative likelihood ratio 0.30 (0.13,0.68) (single study). For small for gestational age it was AFP>2.0MoM to predict birth weight < 10^thcentile with birth < 37 weeks positive likelihood ratio 27.96 (8.02,97.48) and negative likelihood ratio 0.78 (0.55,1.11) (single study). A potential clinical application using aspirin as a treatment is given as an example.</p> <p>There were methodological and reporting limitations in the included studies thus studies were heterogeneous giving pooled results with wide confidence intervals.</p> <p>Conclusion</p> <p>Down's serum screening analytes have low predictive accuracy for pre-eclampsia and small for gestational age. They may be a useful means of risk assessment or of use in prediction when combined with other tests.</p