Altered Platelet Function in Intrauterine Growth Restriction: A Cause or a Consequence of Uteroplacental Disease?

Objective A limited number of platelet function studies in intrauterine growth restriction (IUGR) have yielded conflicting results. We sought to evaluate platelet reactivity in IUGR using a novel platelet aggregation assay. Study Design Pregnancies with IUGR were recruited from 24 weeks' gestation (estimated fetal weight < 10th centile) and had platelet function testing performed after diagnosis. A modification of light transmission aggregometry created dose-response curves of platelet reactivity in response to multiple agonists at differing concentrations. Findings were compared with healthy third trimester controls. IUGR cases with a subsequent normal birth weight were analyzed separately. Results In this study, 33 pregnancies retained their IUGR diagnosis at birth, demonstrating significantly reduced platelet reactivity in response to all agonists (arachidonic acid, adenosine diphosphate, collagen, thrombin receptor-activating peptide, and epinephrine) when compared with 36 healthy pregnancy controls (p < 0.0001). Similar results were obtained for cases demonstrating an increasing in utero growth trajectory. When IUGR preceded preeclampsia or gestational hypertension, platelet function was significantly reduced compared with normotensive IUGR. Conclusion Using this comprehensive platelet assay, we have demonstrated a functional impairment of platelets in IUGR. This may reflect platelet-derived placental growth factor release. Further evaluation of platelet function may aid in the development of future platelet-targeted therapies for uteroplacental disease.

Blood transfusion after vaginal hysterectomy for pelvic organ prolapse.

BACKGROUND AND AIMS: Hysterectomy is a commonly performed gynaecological procedure, and vaginal hysterectomy for the treatment of pelvic organ prolapse will become more common as our population ages. Red cell transfusion after hysterectomy has been reported in the literature as between 2.5 and 4.3%. This paper aimed to review the rate of red cell transfusion after vaginal hysterectomy for pelvic organ prolapse in three university-affiliated teaching hospitals. METHODS: We reviewed 108 vaginal hysterectomies performed across three teaching hospitals to determine the rate of post-operative blood transfusion. RESULTS: A total of 1.9% (2/108) of women received at least one unit of red cells after their vaginal hysterectomy in our cohort. The mean drop in haemoglobin was 2.0 (95% CI, 1.8-2.3, P < 0.001). CONCLUSIONS: Red cell transfusion remains lower than international figures. This may form part of patient counselling when discussing the route of hysterectomy in the future.

Reduced spontaneous platelet aggregation: a novel risk factor for adverse pregnancy outcome.

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.

Viable pregnancies beyond 28 weeks gestation in women with a history of unexplained recurrent miscarriage have reduced platelet function.

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.

Perinatal outcomes of women with a prior history of unexplained recurrent miscarriage.

OBJECTIVE: We sought to determine subsequent pregnancy outcomes in a cohort of women with a history of unexplained recurrent miscarriage (RM) who were not receiving medical treatment. STUDY DESIGN: This was a prospective cohort study, of women with a history of three unexplained consecutive first trimester losses, who were recruited and followed in their subsequent pregnancy. Control patients were healthy pregnant patients with no previous adverse perinatal outcome. RESULTS: A total of 42 patients with a history of unexplained RM were recruited to the study. About nine (21.4%) experienced a further first trimester miscarriage, one case of ectopic and one case of partial molar pregnancy. About 74% (23/31) of the RM cohort had a vaginal delivery. There was one case of severe pre-eclampsia. The RM group delivered at a mean gestational age of 38 + 2 weeks and with a mean birthweight of 3.23 kg. None of the neonates were under the 10th centile for gestational age. Overall, there was no significant difference in pregnancy outcomes between the two cohorts. CONCLUSION: Our study confirms the reassuring prognosis for achieving a live birth in the unexplained RM population with a very low incidence of adverse events with the majority delivering appropriately grown fetuses at term.

Platelet function in patients with a history of unexplained recurrent miscarriage who subsequently miscarry again.

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.