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Objective: Spontaneous platelet aggregation has not been adequately assessed as a potential risk factor for adverse outcomes in pregnancy. Therefore the objective of this study was to assess spontaneous platelet aggregation (SPA), measured via a novel functional assay, as a risk factor for hypertensive disease and intra-uterine growth restriction (IUGR).Study Design: This was a prospective longitudinal study. Spontaneous platelet aggregation was assessed as a marker of platelet reactivity using a modification of light transmission aggregometry. Platelet reactivity was assessed in four groups: non-pregnant healthy female volunteers (n=30), longitudinally in normal uncomplicated pregnancy (n=50), hypertensive disorder (n=40) and IUGR (n=30). The mean percentage SPA was plotted and compared across all groups.Results: Spontaneous platelet aggregation was significantly reduced in the first trimester compared to the non-pregnant group (p-value=0.003). The mean aggregation for the hypertensive group was 1.9%, (95% CI -0.08 to 4.02) and for the IUGR group was 1.6%, (95% CI -0.6 to 3.72). Platelet aggregation in the hypertensive group was significantly reduced compared to the normal pregnant group (p<0.05). Spontaneous platelet aggregation was also reduced in the IUGR group compared to normal pregnancy (p<0.05).Conclusion: This study demonstrates that a reduction of spontaneous platelet aggregation may be a novel risk factor for adverse pregnancy outcomes such as pre-eclampsia and IUGR. The most clinically significant finding is that SPA is significantly lower in pregnancies complicated by hypertension and IUGR compared to those who had a normal pregnancy outcome. Further studies should be carried out to asses if spontaneous platelet aggregation may be a clinically useful tool for the prediction of pre-eclampsia and IUGR. [ABSTRACT FROM AUTHOR]

Background: In contemporary practice many nulliparous women require intervention during childbirth such as operative vaginal delivery or cesarean delivery (CD). Despite the knowledge that the increasing rate of CD is associated with increasing maternal age, obesity and larger infant birthweight, we lack a reliable method to predict the requirement for such potentially hazardous obstetric procedures during labor and delivery. This issue is important, as there are greater rates of morbidity and mortality associated with unplanned CD performed in labor compared with scheduled CDs. A prediction algorithm to identify women at risk of an unplanned CD could help reduced labor associated morbidity.Objective: In this primary analysis of the Genesis study, our objective was to prospectively assess the use of prenatally determined, maternal and fetal, anthropomorphic, clinical, and ultrasound features to develop a predictive tool for unplanned CD in the term nulliparous woman, before the onset of labor.Materials and Methods: The Genesis study recruited 2336 nulliparous women with a vertex presentation between 39+0 and 40+6 weeks' gestation in a prospective multicenter national study to examine predictors of CD. At recruitment, a detailed clinical evaluation and ultrasound assessment were performed. To reduce bias from knowledge of these data potentially influencing mode of delivery, women, midwives, and obstetricians were blinded to the ultrasound data. All hypothetical prenatal risk factors for unplanned CD were assessed as a composite. Multiple logistic regression analysis and mathematical modeling was used to develop a risk evaluation tool for CD in nulliparous women. Continuous predictors were standardized using z scores.Results: From a total enrolled cohort of 2336 nulliparous participants, 491 (21%) had an unplanned CD. Five parameters were determined to be the best combined predictors of CD. These were advancing maternal age (odds ratio [OR], 1.21; 95% confidence interval [CI], 1.09 to 1.34), shorter maternal height (OR, 1.72; 95% CI, 1.52 to 1.93), increasing body mass index (OR, 1.29; 95% CI, 1.17 to 1.43), larger fetal abdominal circumference (OR, 1.23; 95% CI, 1.1 to 1.38), and larger fetal head circumference (OR, 1.27; 95% CI, 1.14 to 1.42). A nomogram was developed to provide an individualized risk assessment to predict CD in clinical practice, with excellent calibration and discriminative ability (Kolmogorov-Smirnov, D statistic, 0.29; 95% CI, 0.28 to 0.30) with a misclassification rate of 0.21 (95% CI, 0.19 to 0.25).Conclusion: Five parameters (maternal age, body mass index, height, fetal abdominal circumference, and fetal head circumference) can, in combination, be used to better determine the overall risk of CD in nulliparous women at term. A risk score can be used to inform women of their individualized probability of CD. This risk tool may be useful for reassuring most women regarding their likely success at achieving an uncomplicated vaginal delivery as well as selecting those patients with such a high risk for CD that they should avoid a trial of labor. Such a risk tool has the potential to greatly improve planning hospital service needs and minimizing patient risk. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to characterize platelet function in pregnant patients with a history of unexplained recurrent miscarriage (RM) in the third trimester of a subsequent viable pregnancy, a time at which platelet dysfunction may be associated with an increased obstetric risk.Study Design: A prospective study was performed comparing 30 viable pregnancies that had reached at least 28 weeks' gestation amongst patients who had a background history of unexplained RM, with 30 healthy pregnant controls at a similar gestational age. Platelet function was determined by means of platelet aggregation in response to 5 different agonists at multiple concentrations.Results: Amongst the 30 RM patients with ongoing viable pregnancies, we demonstrated significantly reduced platelet aggregation compared to the pregnant controls in the third trimester. For three out of five agonists, we demonstrated statistically significantly decreased platelet aggregation and for all five agonists we demonstrated significantly decreased platelet aggregation in the postnatal period. There were no obvious differences in obstetric outcomes.Conclusion: This study shows that women with a history of unexplained RM have reduced platelet function after 28 weeks' gestation in their subsequent pregnancies compared to healthy pregnant controls, but without this difference leading to any obvious increase in adverse obstetric risk. [ABSTRACT FROM AUTHOR]

Objective This study was designed to evaluate platelet aggregation in pregnant women with a history of unexplained recurrent miscarriage (RM) and to compare platelet function in such patients who go on to have either another subsequent miscarriage or a successful pregnancy. Study design A prospective longitudinal study was performed to evaluate platelet function in a cohort of patients with a history of unexplained RM. Platelet reactivity testing was performed at 4–7 weeks gestation, to compare platelet aggregation between those with a subsequent miscarriage and those who had successful live birth outcomes. Platelet aggregation was calculated using a modified assay of light transmission aggregometry with multiple agonists at different concentrations. Results In a cohort of 39 patients with a history of RM, 30 had a successful pregnancy outcome while nine had a subsequent miscarriage again. Women with subsequent miscarriage had reduced platelet aggregation in response to adenosine diphosphate ( P value 0.0012) and thrombin receptor activating peptide ( P value 0.0334) when compared to those with successful pregnancies. Women with subsequent miscarriages also had a trend towards reduced platelet aggregation in response to epinephrine ( P value 0.0568). Conclusion Patients with a background history of unexplained RM demonstrate reduced platelet function if they have a subsequent miscarriage compared to those who go on to have a successful pregnancy. [ABSTRACT FROM AUTHOR]