Retrospective analysis of platelet numbers and volumes in normal pregnancy and in pre-eclampsia

Variables affecting the potential efficacy of PRP in providing chronic pain relief

Although chronic pain affects about 1% of the US population, it remains largely resistant to treatment. Despite great variability in pain outcomes, the application of autologous platelet-rich plasma (PRP) has become increasingly popular in attempts to reduce chronic pain. The variability in PRP efficacy raises the question of whether PRP actually has an analgesic capacity, and if so, can that capacity be made consistent and maximized. The best explanation for the variability in PRP analgesic efficacy is the failure during PRP preparation and application to take into account variables that can increase or eliminate its analgesic capabilities. This suggests that if the variables are reduced and controlled, a PRP preparation and application protocol can be developed leading to PRP inducing reliable, complete, and long-term pain relief. The goal of this study was to examine some of the variables that influence platelets and see how they might be controlled to increase the analgesic potential of PRP. Among the variables examined are the physiological status of the patient, methods used to prepare PRP, and methods of PRP application. The goal of modifying these variables is to minimize platelet serotonin content, maximize platelet content of factors that reduce inflammation and pain, while maintaining their bioactivity, maximize platelet capacity to aggregate at injury sites, induce rapid and simultaneous release of their contents, and optimize PRP application protocols. It is concluded that controlling some or many of these variables will lead to PRP that induces reliable, maximum, and long-term relief of chronic pain.

Early onset preeclampsia is associated with an elevated mean platelet volume (MPV) and a greater rise in MPV from time of booking compared with pregnant controls: results of the CAPE study

OBJECTIVE

To characterise Mean platelet volume (MPV) in patients with early onset preeclampsia (EOPE) and unaffected controls from time of first antenatal visit until the postpartum.

MATERIALS AND METHODS

Retrospective secondary analysis of an observational study in an Irish tertiary referral centre with 9000 deliveries annually. The MPV of 27 women with EOPE was compared to 19 unaffected controls. The inclusion criteria for the disease state was the development of EOPE defined by the National Institute for Health and Care Excellence (NICE) guideline, as new onset hypertension presenting after 20 weeks and prior to 34 weeks with significant proteinuria. Between October 2013 and July 2015 we recruited 27 women with EOPE and 19 pregnant controls. Statistical analysis was performed using paired T-test of Mann-Whitney test where appropriate and a P-value <0.05 was deemed significant.

RESULTS

At time of diagnosis and late in the third trimester MPV was significantly increased to 9.0 (±0.3) fL in cases of EOPE in comparison to 8.5 (±0.6) fL in normotensive controls (P<0.05). There was no significant difference during the first trimester or postpartum when comparing the MPV in EOPE to controls.

CONCLUSION

Despite an increased MPV at time of diagnosis of EOPE this study did not demonstrate a potential use for increased MPV as a first trimester screening tool.

The profiles of soluble adhesion molecules in the "great obstetrical syndromes". J Matern Fetal Neonatal Med 2018;32:2113-2136. [PMID: 29320948 DOI: 10.1080/14767058.2018.1427058]

OBJECTIVE

The objective of this study was to determine the profiles of maternal plasma soluble adhesion molecules in patients with preeclampsia, small-for-gestational-age (SGA) fetuses, acute pyelonephritis, preterm labor with intact membranes (PTL), preterm prelabor rupture of the membranes (preterm PROM), and fetal death.

MATERIALS AND METHODS

A cross-sectional study was conducted to determine maternal plasma concentrations of sE-selectin, sL-selectin, and sP-selectin as well as sICAM-1, sVCAM-1, and sPECAM-1 in patients with (1) an uncomplicated pregnancy (control, n = 100); (2) preeclampsia (n = 94); (3) SGA fetuses (in women without preeclampsia/hypertension, n = 45); (4) acute pyelonephritis (n = 25); (5) PTL (n = 53); (6) preterm PROM (n = 24); and (7) fetal death (n = 34). Concentrations of soluble adhesion molecules and inflammatory cytokines (tumor necrosis factor (TNF)-α and interleukin (IL)-8) were determined with sensitive and specific enzyme-linked immunoassays.

RESULTS

In comparison to women with a normal pregnancy, (1) women with preeclampsia had higher median concentrations of sE-selectin, sP-selectin, and sVCAM-1, and a lower concentration of sL-selectin (all p values < .001); (2) patients with SGA fetuses had higher median concentrations of sE-selectin, sP-selectin, and sVCAM-1 (all p values < .05); (3) patients with a fetal death had higher median concentrations of sE-selectin and sP-selectin (all p values < .05); (4) patients with acute pyelonephritis had higher median plasma concentrations of sE-selectin, sICAM-1, and sVCAM-1 (all p values < .001); (5) patients with preeclampsia and acute pyelonephritis, plasma concentrations of sVCAM-1, sE-selectin, and sP-selectin correlated with those of the proinflammatory cytokines TNF-α and interleukin (IL)-8 (all p values < .05); (6) patients with PTL had a higher median concentration of sP-selectin and a lower median concentration of VCAM-1 (all p values < .05); and (7) women with preterm PROM had lower median concentrations of sL-selectin and sVCAM-1 (all p values < .05).

CONCLUSIONS

The results of this study show that endothelial cell activation/dysfunction reflected by the plasma concentration of sE-selectin is not specific to preeclampsia but is present in pregnancies complicated by SGA fetuses, acute pyelonephritis, and fetal death. Collectively, we report that each obstetrical syndrome appears to have a stereotypical profile of soluble adhesion molecules in the peripheral circulation.

Platelet Count in First Trimester of Pregnancy as a Predictor of Perinatal Outcome

AIM:

To rule out maternal and pregnancy factors that may contribute to platelet count (PLT) changes in the first trimester of gestation and examine if there is any association between its levels and adverse perinatal outcome.

METHODS:

The study population included all patients from the first-trimester visit between 2013-2015 with pregnancy results. Linear multiple regression was constructed to rule out variables that may have a significant contribution to PLT. For each adverse outcome at birth, multiple logistic regression analysis was implemented to estimate the PLT effect.

RESULTS:

PLT was measured in 6092 patients. There was the significant contribution on PLT in the first trimester from maternal weight, the presence of rheumatologic disease, BHCG levels and MPV. There was a significant association between PLT and abnormal cardiotocography at delivery (OR 1.004; IC95% 1.001 to 1.007) and C-Section due to abnormal CTG (OR 1.005; IC95% 1.002 to 1.008). When adjusted for factors that interact with PLT there was also a significant association with pH at birth < 7.10 and gestational diabetes.

CONCLUSIONS:

Maternal and pregnancy factors can poorly predict relevant changes in PLT at the first trimester of gestation. PLT at first trimester of pregnancy might predict adverse perinatal outcome in combination with other markers.

Women with Cirrhosis: Prevalence, Natural History, and Management

Cirrhosis is less frequent in women than in men, in large part due to the lower prevalence of hepatitis B, hepatitis C, and alcohol use in women. The most common causes of cirrhosis among women are hepatitis C, autoimmune etiologies, nonalcoholic steatohepatitis, and alcoholic liver disease. For most chronic liver diseases, the risk of progression to cirrhosis and rates of liver failure and hepatocellular carcinoma are lower in women than in men. Pregnancy is very infrequent in women with cirrhosis due to reduced fertility, but when it occurs, requires specialized management.

The effect of molar pregnancies on platelet parameters

The aim of this study was to compare platelet parameters between abortus groups with gestational trophoblastic disease (GTD) (molar pregnancy, invasive mole, choriocarcinoma, etc) and without disease according to pathological result. The study population consisted of patients with GTD (n = 53) and aborted patients without disease as a control group (n = 53) who were seen in our clinic between January 2010 and December 2013. In this retrospective study, age, gravidity, levels of haemoglobin, white blood cell count, platelets, platelet parameters (mean platelet volume (MPV), platelet distrubition width (PDW), platelet crit (PCT), which shows platelet functions were recorded. The pathological diagnosis of GTD was recorded. The mean platelet count, MPV, PDW and PCT levels were similar between the groups. There is no statistically significiant difference between types of GTN in these parameters according to pathological diagnosis. According to our study results, platelet count and levels of MPV, PDW ve PCT in GTD patients were similar to aborted patients without disease.

Altered mean platelet volume in patients with polymyositis and its association with disease severity

Polymyositis (PM) is an autoimmune disease characterized by chronic inflammation in skeletal muscle. Mean platelet volume (MPV), a marker in the assessment of systemic inflammation, is easily measured by automatic blood count equipment. However, to our knowledge, there are no data in the literature with respect to MPV levels in PM patients. Therefore, in this study we aimed to investigate MPV levels in patients with PM. This study included 92 newly diagnosed PM patients and 100 healthy individuals. MPV levels were found to be significantly lower compared with healthy controls (10.3±1.23 vs 11.5±0.74 fL, P<0.001). Interestingly, MPV was found to be positively correlated with manual muscle test (MMT) score and negatively correlated with erythrocyte sedimentation rate (ESR) in patients with PM (r=0.239, P=0.022; r=-0.268, P=0.010, respectively). In addition, MPV was significantly lower in active PM patients compared with inactive PM patients (9.9±1.39 vs 10.6±0.92 fL, P=0.010). MPV was independently associated with PM in multivariate regression analyses, when controlling for hemoglobin and ESR (OR=0.312, P=0.031, 95%CI=0.108 to 0.899). The ROC curve analysis for MPV in estimating PM patients resulted in an area under the curve of 0.800, with sensitivity of 75.0% and specificity of 67.4%. Our results suggest that MPV is inversely correlated with disease activity in patients with PM. MPV might be a useful tool for rapid assessment of disease severity in PM patients.

Intrapartum mean platelet volume is not a useful predictor of new-onset delayed postpartum pre-eclampsia

OBJECTIVE

To determine whether intrapartum mean platelet volume (MPV) can predict new-onset delayed postpartum pre-eclampsia.

METHODS

In a retrospective study, data were obtained for women with delayed postpartum pre-eclampsia (≥48 hours after delivery) who attended the Detroit Medical Center, Detroit, MI, USA, between January 2002 and July 2010. Patients were divided into two subgroups: new-onset delayed postpartum pre-eclampsia (no history of hypertensive disorder before 48 hours after delivery) and other late-onset/delayed postpartum pre-eclampsia (history of hypertensive disorders). Cases with no hypertensive disorders paired by delivery date were selected as controls. Receiver operating characteristic (ROC) curves were used to determine whether MPV could distinguish between cases and controls.

RESULTS

Data for 130 cases of new-onset delayed postpartum pre-eclampsia, 71 cases of other late-onset/delayed postpartum pre-eclampsia, and 405 controls were collected. MPV was significantly different between the pre-eclampsia subgroups (P=0.007). ROC curves showed that MPV significantly distinguished new-onset delayed postpartum pre-eclampsia cases (area under the curve 0.6, 95% confidence interval 0.5-0.6; P=0.02), with a sensitivity and specificity of 58.1% and 55.4%, respectively.

CONCLUSION

Although MPV was significantly lower in women who went on to develop new-onset delayed postpartum pre-eclampsia than among controls, it is not a useful predictor. The low MPV suggests a different mechanism for the development of new-onset delayed postpartum pre-eclampsia.

Endocan, a putative endothelial cell marker, is elevated in preeclampsia, decreased in acute pyelonephritis, and unchanged in other obstetrical syndromes

Objective: Endocan, a dermatan sulphate proteoglycan produced by endothelial cells, is considered a biomarker for endothelial cell activation/dysfunction. Preeclampsia is characterized by systemic vascular inflammation, and endothelial cell activation/dysfunction. Therefore, the objectives of this study were to determine whether: (1) plasma endocan concentrations in preeclampsia differ from those in uncomplicated pregnancies; (2) changes in plasma endocan concentration relate to the severity of preeclampsia, and whether these changes are specific or observed in other obstetrical syndromes such as small-for-gestational age (SGA), fetal death (FD), preterm labor (PTL) or preterm prelabor rupture of membranes (PROM); (3) a correlation exists between plasma concentration of endocan and angiogenic (placental growth factor or PlGF)/anti-angiogenic factors (soluble vascular endothelial growth factor receptor or sVEGFR-1, and soluble endoglin or sEng) among pregnancies complicated by preeclampsia; and (4) plasma endocan concentrations in patients with preeclampsia and acute pyelonephritis (both conditions in which there is endothelial cell activation) differ.

Method: This cross-sectional study included the following groups: (1) uncomplicated pregnancy (n = 130); (2) preeclampsia (n = 102); (3) pregnant women without preeclampsia who delivered an SGA neonate (n = 51); (4) FD (n = 49); (5) acute pyelonephritis (AP; n = 35); (6) spontaneous PTL (n = 75); and (7) preterm PROM (n = 64). Plasma endocan concentrations were determined in all groups, and PIGF, sEng and VEGFR-1 plasma concentrations were measured by ELISA in the preeclampsia group.

Results: (1) Women with preeclampsia had a significantly higher median plasma endocan concentration than those with uncomplicated pregnancies (p = 0.004); (2) among women with preeclampsia, the median plasma endocan concentration did not differ significantly according to disease severity (p = 0.1), abnormal uterine artery Doppler velocimetry (p = 0.7) or whether diagnosis was made before or after 34 weeks gestational age (p = 0.3); (3) plasma endocan concentration in women with preeclampsia correlated positively with plasma anti-angiogenic factor concentrations [sVEGFR-1: Spearman rho 0.34, p = 0.001 and sEng: Spearman rho 0.30, p = 0.003]; (4) pregnancies complicated by acute pyelonephritis with bacteremia had a lower median plasma endocan concentration than pregnancies complicated by acute pyelonephritis without bacteremia (p = 0.004), as well as uncomplicated pregnancies (p = 0.001); and (5) there was no significant difference in the median plasma endocan concentration between uncomplicated pregnancies and those complicated by FD, delivery of an SGA neonate, PTL or preterm PROM (other members of the “great obstetrical syndromes”; each p > 0.05).

Conclusion: Median maternal plasma endocan concentrations were higher preeclampsia and lower in acute pyelonephritis with bacteremia than in uncomplicated pregnancy. No significant difference was observed in the median plasma endocan concentration between other great obstetrical syndromes and uncomplicated pregnancies. The difference in the direction of change of endocan in preeclampsia and acute pyelonephritis with bacteremia may be consistent with the view that both disease entities differ in pathogenic mechanisms, despite their associations with systemic vascular inflammation and endothelial cell activation/dysfunction.

Maternal plasma fetuin-A concentration is lower in patients who subsequently developed preterm preeclampsia than in uncomplicated pregnancy: a longitudinal study

Objective: Fetuin-A is a negative acute phase protein reactant that acts as a mediator for lipotoxicity, leading to insulin resistance. Intravascular inflammation and insulin resistance have been implicated in the mechanisms of disease responsible for preeclampsia (PE). Maternal plasma concentrations of fetuin-A at the time of diagnosis of preterm PE are lower than in control patients with a normal pregnancy outcome. However, it is unknown if the changes in maternal plasma fetuin-A concentrations precede the clinical diagnosis of the disease. We conducted a longitudinal study to determine whether patients who subsequently developed PE had a different profile of maternal plasma concentrations of fetuin-A as a function of gestational age (GA) than those with uncomplicated pregnancies. Methods: A longitudinal case-control study was performed and included 200 singleton pregnancies in the following groups: (1) patients with uncomplicated pregnancies who delivered appropriate for gestational age (AGA) neonates (n = 160); and (2) patients who subsequently developed PE (n = 40). Longitudinal samples were collected at each prenatal visit and scheduled at 4-week intervals from the first or early second trimester until delivery. Plasma fetuin-A concentrations were determined by ELISA. Analysis was performed using mixed-effects models. Results: The profiles of maternal plasma concentrations of fetuin-A differ between PE and uncomplicated pregnancies. Forward analysis indicated that the rate of increase of plasma fetuin-A concentration in patients who subsequently developed PE was lower at the beginning of pregnancy (p = 0.001), yet increased faster mid-pregnancy (p = 0.0017) and reached the same concentration level as controls by 26 weeks. The rate of decrease was higher towards the end of pregnancy in patients with PE than in uncomplicated pregnancies (p = 0.002). The mean maternal plasma fetuin-A concentration was significantly lower in patients with preterm PE at the time of clinical diagnosis than in women with uncomplicated pregnancies (p < 0.05). In contrast, there were no significant differences in maternal plasma fetuin-A concentration in patients who developed PE at term. Conclusions: (1) The profile of maternal plasma concentrations of fetuin-A over time (GA) in patients who develop PE is different from that of normal pregnant women; (2) the rate of change of maternal plasma concentrations of fetuin-A is positive (increases over time) in the midtrimester of normal pregnancy, and negative (decreases over time) in patients who subsequently develop PE; (3) at the time of diagnosis, the maternal plasma fetuin-A concentration is lower in patients with preterm PE than in those with a normal pregnancy outcome; however, such differences were not demonstrable in patients with term PE.

Can platelet count and mean platelet volume during the first trimester of pregnancy predict preterm premature rupture of membranes?

AIM

The aim of our study was to evaluate the values of platelet count and mean platelet volume (MPV) obtained from maternal serum during the first trimester to predict subsequent preterm premature rupture of membranes (PPROM).

MATERIAL AND METHODS

The records of 318 women with PPROM and 384 healthy controls in a single center between 2009 and 2013 were retrospectively evaluated. Platelet count and MPV values between 7 and 14 weeks of gestation were compared. Receiver-operator curve analysis was performed to identify the optimal platelet count and MPV cut-off levels predicting PPROM.

RESULTS

Compared with controls, women with PPROM had significantly increased levels of platelet count and significantly decreased levels of MPV in the first trimester (P < 0.001). The area under the receiver-operator curve was 0.642 for MPV and 0.579 for platelet count. The cut-off values of MPV ≤ 8.6 fL and platelet count ≥216 × 10(3) /μL predicted PPROM with a sensitivity of 58% and 65% and specificity of 62% and 44%, respectively.

CONCLUSION

MPV can be used as a more efficient predictor for an early diagnosis of PPROM than platelet count. However, further research combining other markers is needed to increase the efficiency of prediction.

Validation of reportable indices of haematology, liver and renal function in pregnancy for the Middle Eastern population

The objective of this study was to describe normative values of complete blood counts, kidney and liver function tests for Jordanian women. A prospective study of 797 healthy pregnant women, seen at the antenatal clinics of the Jordan University of Science and Technology, in Irbid, north Jordan, was conducted between January 2005 and December 2009. Differences by trimester were analysed using one-way ANOVA. The mean age of the women was 31.0 years. The mean gestational age at delivery was 38.2 weeks. It was concluded that complete blood counts, kidney and liver function values by trimester, of healthy pregnant population of Jordanian women, were consistent with data reported for other populations.

Predictive Value of Platelet Indices in Development of Preeclampsia

Aim

To evaluate the association between changes in platelet indices (platelet count, mean platelet volume, platelet distribution width) and development of preeclampsia.

Materials and methods

Two hundred pregnant women at 20 to 24 weeks of gestation with singleton pregnancy and normal blood pressure were enrolled after taking well-informed consent. At monthly intervals CBC (complete blood count) was done from 20 to 24 weeks till 40 weeks and 7 days after delivery. Data regarding changes in platelet indices with increasing gestation was collected and analyzed.

Results

Platelet count decreased significantly in patients with preeclampsia compared to normal pregnant patients (19.4% vs 7.4%). Mean platelet volume increased significantly in preeclampsia patients (44.5% vs 9.22%). Increase in PDW was observed significantly in patients with preeclampsia (47.19% vs 29.4%).

Conclusion

Patients with preeclampsia are more likely to have significant decrease in platelet count, increase in PDW and MPV. These changes can be observed at an earlier gestational age than significant rise in BP can be observed and are directly proportional to progressive rise in hypertension. Thus, estimation of platelet indices can be considered as an early, simple and cost-effective procedure in the assessment of severity of preeclampsia.

How to cite this article

Dadhich S, Agrawal S, Soni M, Choudhary R, Jain R, Sharma S, Saini SL. Predictive Value of Platelet Indices in Development of Preeclampsia. J South Asian Feder Obst Gynae 2012;4(1):17-21.

Physiologic and pathologic changes of platelets in pregnancy

Platelets are key players in haemostasis and thrombus formation. Defects affecting platelets during pregnancy can lead to heterogeneous complications, such as thrombosis, first trimester miscarriage and postpartum haemorrhage. The incidence of complications is increased in women who have heritable platelet function disorders. Modifications of platelet count or platelet functions during normal pregnancy and preeclampsia will be summarized and the management of pregnant women with heritable platelet function disorders will be discussed.

Doppler velocimetry alterations related to platelet changes in third trimester pregnancies

The aim of this study was to evaluate the correlations between the haematological parameter mean platelet volume and Doppler velocimetry parameters in order to improve clinical management in third trimester complicated pregnancies (pre-eclampsia, PE, and IUGR) affected by altered uterine resistances. Fifty-one patients were included in the abnormal uterine arteries Doppler velocimetry group (25 pregnancies were complicated by PE, 26 pregnancies were complicated by IUGR). Ninety-nine normotensive pregnant women taking no drugs for at least 2 weeks prior to testing and with no difference in gestational age at evaluation, with normal Doppler velocimetry profiles at routine screen, were used as controls. From all pregnant women, 20 mL of whole blood were obtained into citrate tubes after Doppler velocimetry evaluation and analysed for red blood cell counts (RBC), mean corpuscular volume (MCV), haemoglobin (HGB), haematocrit level (HCT), white blood cells count (WBC), platelet counts (PLT), mean platelets volume (MPV) and other biochemical parameters. From all blood parameters studied, MPV was significantly higher in women with altered uterine artery Doppler velocimetry compared with those with normal Doppler profiles (9.4 +/- 1.0 vs. 8.05 +/- 1.2 fL, P<0.001). In the group with altered uterine artery Doppler velocimetry, pregnancies complicated by PE showed a MPV value higher than pregnancies affected by IUGR (9.5 +/- 1.6 vs. 8.9 +/- 1.1, P<0.001). Finally, mean uterine arteries RI values were significantly related to MPV (fL) in both PE and IUGR groups (P<0.01, r=0.37 and P<0.01, r=0.38, respectively). Our study shows that a periodical monitoring of haematological parameters such as MPV can be associated to Doppler velocimetry in order to improve the management of pregnancies with uterine arteries Doppler velocimetry alterations.

Intraplatelet cyclic guanosine-3',5'-monophosphate levels during pregnancy and preeclampsia

OBJECTIVE

To investigate the intraplatelet cyclic guanosine-3',5'-monophosphate (cGMP) levels during normal pregnancy and preeclampsia.

STUDY DESIGN

Pregnant women (n = 15), women with preeclampsia (n = 15), and nonpregnant, normotensive women (n = 15) were included. Intraplatelet cyclic guanosine-3',5'-monophosphate levels were measured by an enzyme-linked immunosorbent assay.

RESULTS

Intraplatelet cGMP levels were significantly different among all groups (p < 0.02). The values were higher in normal pregnant women (mean 19.8 SD 2.6 fmol/10(5) platelets) in comparison to nonpregnant women (mean 7.6 SD 0.3 fmol/10(5)platelets; p = 0.001) and women with preeclampsia (mean 11.3 SD 1.8 fmol/10(5) platelets; p = 0.05). Plasma nitric oxide levels did not reveal differences between all groups.

CONCLUSIONS

The results of this study in a high-risk Andean population demonstrated that intraplatelet cyclic guanosine-3',5'-monophosphate levels are decreased during preeclampsia compared to normal pregnancy, suggesting a lack in action of nitric oxide.

Prenatal screening, epidemiology, diagnosis, and management of preeclampsia

The cause of preeclampsia remains unknown. The disease manifests itself across a broad clinical spectrum from mild to severe, conferring vastly different morbidities and suggesting possibly different disease processes. Oxidative stress, endothelial dysfunction, maternal-fetal immune incompatibility, and abnormal placental implantation are among the suggested causes. The need for a marker or set of markers that allow for definitive diagnosis and assessment of future risk of preeclampsia is tremendous. Ultrasound techniques and several markers have been identified that are increased among patients with preeclampsia, but no test is highly sensitive. In the future, a combination of markers likely will be used to assess risk and, establish the diagnosis, and test treatment strategies. Such an approach would allow for more refined treatment studies of patients who are at highest risk for preeclampsia.

Platelet changes and subsequent development of pre-eclampsia and fetal growth restriction in women with abnormal uterine artery Doppler screening

OBJECTIVES

To investigate whether, in women with abnormal uterine artery Doppler, platelet volume and function will identify a subgroup of women at increased risk of pre-eclampsia and intrauterine growth restriction and whether in-vitro platelet aggregation precedes the onset of clinical disease.

DESIGN

Platelet number, volume and aggregation induced by collagen or adenosine 5'-diphosphate were evaluated in 16 non-pregnant controls, 29 pregnant women with normal uterine artery Doppler and 31 pregnant women with abnormal Doppler, hence at risk of pre-eclampsia and intrauterine growth restriction at 23 weeks. Outcome of pregnancy was recorded in each case.

RESULTS

Twelve women in the group with abnormal uterine artery Doppler subsequently developed pre-eclampsia and/or intrauterine growth restriction. All women with normal uterine artery Doppler had a normal pregnancy outcome. No differences in platelet count or in vitro platelet aggregation induced by collagen were observed between the groups. Mean platelet volume was greater in those with abnormal Doppler who had intrauterine growth restriction or normal pregnancy outcome compared with normal Doppler (10.3 and 10.3 vs. 9.4 fL, P = 0.004 and P = 0.01, respectively). Aggregation induced by adenosine diphosphate was higher in women with abnormal Doppler who developed pre-eclampsia or intrauterine growth restriction compared with those with normal outcomes (66.5 and 66.5 vs. 21%, P = 0.02, P = 0.03, respectively).

CONCLUSIONS

Women with abnormal uterine artery Doppler at 23 weeks show alterations in mean platelet volume and platelet function that relate to subsequent adverse outcome.

Mean platelet volume: a useful marker of inflammatory bowel disease activity

OBJECTIVES

We investigated whether the mean platelet volume would be a useful marker in the evaluation of inflammatory bowel disease activity.

METHODS

Complete blood count, C-reactive protein, erythrocyte sedimentation rate, serum thrombopoietin and erythropoietin, plasma beta-thromboglobulin, and platelet factor 4 were measured in 93 patients with ulcerative colitis, 66 patients with Crohn's disease, and 38 healthy blood donors. Disease activity was assessed by the Clinical Colitis Activity Index in patients with ulcerative colitis and by the Crohn's Disease Activity Index in patients with Crohn's disease.

RESULTS

Mean platelet count was increased in patients with active compared to inactive ulcerative colitis (p < 0.05), and in patients with active compared to inactive Crohn's disease (p = 0.0002) or healthy controls (p < 0.0001). On the other hand, mean platelet volume was significantly decreased in patients with active compared to inactive ulcerative colitis (p = 0.02) or healthy controls (p < 0.0001), and in patients with active compared to inactive Crohn's disease (p = 0.0005) or healthy controls (p < 0.0001). Mean platelet volume was inversely correlated with the white blood cell count (r = -0.17, p = 0.02), C-reactive protein (r = -0.46, p = 0.009) and erythrocyte sedimentation rate (r = -0.28, p = 0.008). No significant correlations were found between mean platelet volume and serum thrombopoietin or erythropoietin levels; however, a strong negative correlation between mean platelet volume and beta-thromboglobulin (r = -0.34, p < 0.0001) and platelet factor 4 (r = -0.30, p = 0.0002) was observed.

CONCLUSIONS

Mean platelet volume is significantly reduced in active inflammatory bowel disease and is negatively correlated with the known inflammatory bowel disease activity markers and the platelet activation products. We propose that mean platelet volume provides a useful marker of activity in inflammatory bowel disease.

The determination of a reference range for new platelet parameters produced by the Bayer ADVIA120 full blood count analyser

One hundred and twenty-two samples from normal volunteers were processed for full blood count analysis through the Bayer ADVIA120. The samples were simultaneously tested using the marker CD62P to establish the absence of platelet activation. Samples were tested at two time intervals, 20 min and 3.5 h, to simulate the testing practice for routine and urgent samples in our laboratory. From these data the mean and reference ranges, with 95% confidence limits, for platelet parameters were calculated for the ADVIA120. The time difference for some platelet parameters was significant. Hence two ranges have been reported. The age or smoking habit of the volunteer did not significantly affect platelet results but there was a statistically significant sex difference in some platelet parameters.

Association of a decrease in antithrombin III activity with a perinatal elevation in aspartate aminotransferase in women with twin pregnancies: relevance to the HELLP syndrome

BACKGROUND/AIMS

Decreased antithrombin III (AT-III) activity and/or thrombocytopenia associated with an elevated serum level of aspartate aminotransferase in late pregnancy can threaten the lives of both the mother and the fetus. We investigated whether antenatal declines in AT-III activity and the platelet count occur in late twin pregnancy and whether reduced AT-III activity and/or thrombocytopenia precedes an increase in the serum level of aspartate aminotransferase.

METHODS

The platelet count, AT-III activity, and the serum level of aspartate aminotransferase were determined weekly or biweekly in 237 women with twin pregnancies in a longitudinal and partly prospective study.

RESULTS

Both AT-III activity and the platelet count decreased gradually in the last month of pregnancy, irrespective of the presence or absence of clinical signs of pre-eclampsia. A perinatal elevation in aspartate aminotransferase occurred in 36 (15%) of 237 women. The risk of a perinatal elevation in aspartate amino-transferase increased as the antenatal AT-III activity and/or the platelet count decreased. Pre-eclampsia developed in 60 women (25%). The relative risk of a perinatal aspartate aminotransferase elevation (95% confidence interval) for the 60 women with pre-eclampsia, the 60 women with a platelet count < or = the 25th percentile (164 x 10(9)/1), and the 60 women with AT-III activity < or = the 25th percentile (76% of normal) was 1.9 (1.0 to 3.4), 4.1 (2.3 to 7.5), and 5.9 (3.2 to 11.1), respectively, compared with the remaining 177 women.

CONCLUSIONS

AT-III activity and platelet count gradually decreased in the last month of twin pregnancies. A perinatal aspartate aminotransferase elevation was preceded by marked decreases in these parameters in women with twin pregnancies. The monitoring of AT-III activity and platelet count in women who exhibit a gradual decline in these parameters may help to avoid the development of severe HELLP syndrome.

Prediction of preeclampsia

The onset of preeclampsia at or near to term is associated with low maternal and neonatal morbidity and mortality. In contrast, those patients (1%) who suffer early onset preeclampsia engender significant maternal and perinatal morbidity and mortality. Therefore, because of the lack of proven prophylaxis for preeclampsia, prediction of risk or identification of subclinical disease is desirable to identify patients for more intensive observation. There are certain at-risk groups of patients such as those with chronic hypertension, pregestational diabetes, multifetal gestation, and previous preeclampsia. These patients account for the majority of cases of preeclampsia in multiparas, yet only account for 14% of preeclampsia in nulliparous women. Thus, the majority of cases of preeclampsia arises from nulliparous women without medical complications at low risk. Differences in the time of onset, severity, and organ system involvement suggest there may be different underlying etiologies that ultimately lead to preeclampsia manifested as the triad of maternal hypertension, proteinuria, and edema. Distinct markers therefore may identify subgroups of at-risk patients with separate underlying causes. These markers ultimately could be used for diagnosis of disease before the clinical appearance of maternal disease (hypertension, proteinuria, and edema). Based on data from patients with established disease, with the involvement of various organ systems, potential candidate markers would include renal function (kallikrein-creatinine); coagulation and fibrinolytic systems and platelet activation (platelet volume); markers of vascular function (fibronectin, prostacyclin, thromboxane) and oxidant stress (lipid peroxides, 8-isoprostane, antioxidants, anticardiolipin antibodies, hemoglobin, iron, transferrin, homocysteine, hypertriglyceridemia, albumin isoforms); placental peptide hormones (CRH, CRHbp, activin, inhibin, hCG); vascular resistance (uteroplacental flow velocity waveforms); genetic markers; insulin resistance; and glucose intolerance. Although cross-sectional studies have identified these potential markers, they need to be evaluated in prospective longitudinal studies with rigorous definition of outcome to determine if they are useful in predicting preeclampsia and whether they can identify different subgroups of patients.

Increased mean platelet volume after oestrogen replacement therapy

The effect of hormone replacement therapy (HRT) on platelet size was examined in 38 post-menopausal women before and at end of a 6 week period of HRT. Subjects were treated with cyclical L-norgestrel 75 mg daily from days 17 to 28 of a 28-day cycle combined with continuous conjugated equine oestrogens 0.625 mg daily. Platelet-rich plasma was obtained to measure platelet indices by Coulter analysis. Plasma measurements of luteinizing hormone, follicle stimulating hormone and 17 beta-oestradiol were measured by immunoassays. Platelet membrane fatty acids were measured by gas-liquid chromatography. A significant reduction in platelet membrane linoleic acid, di-homo-gamma-linoleic acid and arachidonic acid of 8.1%, 14.3% and 17.8%, respectively was noted after 6 weeks of HRT (p < 0.01). There was an increase in the platelet count (not significant) and platelet volume (MPV) (P < 0.05) after 6 weeks of hormone therapy. HRT appears to increase mean platelet volume which may indicate an increase in platelet reactivity. There was no correlation between the changes in mean platelet volume and membrane fatty acid changes in platelets after such therapy.

Poor predictive value of platelet count, mean platelet volume and serum urate in hypertension in pregnancy

OBJECTIVE

To determine the usefulness of platelet count, mean platelet volume and serum uric acid levels in the prediction of pre-eclampsia in women with mild hypertension in pregnancy, and to see if it is appropriate to base the management of such patients on these tests.

SUBJECTS

Three hundred and thirty-six women attending the antenatal day unit with a diagnosis of non-proteinuric hypertension in pregnancy (diastolic blood pressure > or = 90 mmHg on two separate recordings) from whom at least one blood sample was taken.

MAIN OUTCOMES MEASURED

The development of proteinuria (1+ or greater on urine Albustix); the need for oral antihypertensive medication, the need for the 'pre-eclampsia regime' intra- or post-partum; the need for induction of labour because of hypertension.

RESULTS

No test, at any cut-off level, was found to be of any use in predicting the outcomes studied. Nor was a weekly change in any of the tests found to be of any use.

CONCLUSION

Basing the management of patients with mild non-proteinuric hypertension on the results of platelet count, mean platelet volume or urate level is unwise as none of these tests was able to predict outcome in such patients.

Platelet count and platelet indices at various stages of normal pregnancy in smoking and non-smoking women

Our objective was to compare the platelet count and platelet indices of smoking and non-smoking women at different stages of normal pregnancy.

STUDY DESIGN

In 247 non-smoking and 123 smoking healthy pregnant women the platelet count, the mean platelet volume, the platelet distribution width and the plateletcrit were compared at 0-10, 11-20, 21-30 and 31-40 weeks of pregnancy. Exclusion criteria were a diastolic pressure > or = 90 mmHg, an endocrine disease, a coagulation disorder, acetylsalicylic acid or phenprocoumon use. A women was considered a smoker if she smoked more than 4 cigarettes a day. Non-smokers were defined as women reporting no smoking at all. Blood samples were run on the Sysmex NE-8000.

RESULTS

There was no significant difference between the platelet count in the two groups. In the non-smoking group, the platelet count showed a significant decrease with gestational age (287 x 10(9)/l to 258 x 10(9)/l). This was not the case in the smokers group. The mean platelet volume of the smokers was significantly lower than that of the non-smokers in the last ten weeks of pregnancy (10.4 fl versus 10.7 fl). The platelet distribution width and the plateletcrit did not change under the influence of cigarette smoking.

CONCLUSION

Smoking during pregnancy does not significantly affect platelet count or platelet indices.

Platelet size and glycoprotein Ib and IIIa expression in normal fetal and maternal blood

OBJECTIVE

Our purpose was to study platelet size and surface glycoprotein expression in normal fetal and maternal blood throughout pregnancy.

STUDY DESIGN

A cross-sectional study was performed at the Harris Birthright Research Centre for Fetal Medicine, King's College Hospital Medical School, London. Fetal and maternal blood samples were obtained from uncomplicated pregnancies at 8 to 42 weeks' gestation (n = 101 and n = 117, respectively) and from 30 nonpregnant controls. Flow cytometry was used to determine platelet size and glycoprotein Ib and IIIa expression both before and after stimulation with adenosine diphosphate.

RESULTS

Mean platelet size in both fetal and maternal blood was significantly lower than that of nonpregnant controls and decreased with advancing gestation. The surface density of glycoprotein Ib in maternal and fetal platelets was significantly lower than in nonpregnant controls but did not change with gestation. Adenosine diphosphate stimulation of maternal platelets resulted in increased percentage expression and surface density of all glycoproteins, whereas stimulation of control platelets resulted in increased surface density of glycoprotein Ib and percentage expression of glycoprotein IIIa. Adenosine diphosphate stimulation of fetal platelets resulted in increased surface density of glycoprotein Ib and IIIa.

CONCLUSION

Pregnancy is associated with increased thrombocytopoiesis in both the mother and fetus. Maternal platelet glycoprotein expression and responsiveness to adenosine diphosphate stimulation is increased. Fetal platelets are phenotypically mature from at least 12 weeks' gestation and respond in an adultlike fashion to stimulation with adenosine diphosphate.