Platelet response to aspirin in UK and Irish pregnancy cohorts: a genome-wide approach.

A multi-center prospective cross-sectional and genome-wide association study (GWAS) recruited pregnant women taking low dose aspirin. Objectives were to (i) develop pregnancy-specific 95% reference intervals for a range of laboratory based platelet function tests (PFTs); (ii) select an optimal and acceptable PFT that reflected aspirin's COX-1 inhibition in women with confirmed aspirin adherence in pregnancy; and (iii) identify genomic variants that may influence pregnant women's platelet response to aspirin.The study included two independent cohorts of pregnant women. A range of PFTs and matched phenotyping with urinary 11-dehydrothromboxane B2 (11DTXB2) and nuclear magnetic resonance (NMR) spectroscopy detection of urinary salicyluric acid as a measure of aspirin adherence were performed. Genome-wide data was acquired from the UK Biobank Axiom® (Thermo Fisher Scientific). 11DTXB2 in combination with adherence testing with NMR salicyluric acid was an accurate and acceptable testing strategy for detecting biochemical aspirin responsiveness in pregnant women, with the provision of relevant reference ranges. GWAS meta-analysis found no significant single nucleotide polymorphisms in association with response to aspirin in pregnancy. Further evaluation in relation to effective dosing of aspirin in pregnancy and optimizing the benefits to specific subgroups should now be a priority for future research.

Evaluation of the Effect of Low-Dose Aspirin on Biochemical and Biophysical Biomarkers for Placental Disease in Low-Risk Pregnancy: Secondary Analysis of a Multicenter RCT.

OBJECTIVE: To assess the effect of aspirin use in low-risk pregnancy on: (1) pregnancy-associated plasma protein-A (PAPP-A) and placental-like growth factor (PLGF); (2) urinary albumin-to-creatinine ratio (ACR) and blood pressure; (3) fetal growth parameters; and (4) placental histopathology. STUDY DESIGN: This secondary analysis from the T rial of low-dose aspirin with an E arly S creening T est for preeclampsia and growth restriction randomized controlled trial was based on low-risk nulliparous women randomized at 11 weeks to (1) aspirin 75 mg; (2) no aspirin; and (3) aspirin based on the preeclampsia Fetal Medicine Foundation screening test. At baseline, women underwent assessment of blood pressure, PAPP-A, PLGF, and ACR, repeated 9 to 10 weeks postaspirin, in addition to fetal growth assessment. Gross and histopathological placental analyses were performed in line with Amsterdam criteria. RESULTS: A total of 445 subjects were included (aspirin n = 163 [36.6%]; no aspirin n = 282 [63.4%]). Although the fetal-to-placental weight ratio was significantly greater in the aspirin group (7.5 [±1.3] vs. 7.3 [±1.4], p = 0.045), as was change in ultrasound assessed estimated fetal weight from second to third trimesters (1,624.5 g [±235.1] vs. 1,606.2 [±189.4], p = 0.042), this was invalidated by the lack of a difference in birth weight. Aspirin did not significantly impact on change in serum or urine preeclampsia biomarkers, maternal blood pressure, or placental histopathology. CONCLUSION: Aspirin use in low-risk pregnancy does not appear to impact on preeclampsia biomarkers, fetal growth, or placental pathology.

The Impact of Aspirin on Ultrasound Markers of Uteroplacental Flow in Low-Risk Pregnancy: Secondary Analysis of a Multicenter RCT.

OBJECTIVE: This article evaluates the effect of low-dose aspirin on uterine artery (UtA) Doppler, placental volume, and vascularization flow indices in low-risk pregnancy. STUDY DESIGN: In this secondary analysis of the TEST randomized controlled trial, low-risk nulliparous women were originally randomized at 11 weeks to: (1) routine aspirin 75 mg; (2) no aspirin; and (3) aspirin based upon the preeclampsia Fetal Medicine Foundation screening test. UtA Doppler, three-dimensional (3D) placental volume, and vascularization flow indices were assessed prior to and 6 weeks postaspirin commencement. RESULTS: A total of 546 women were included (aspirin n = 192, no aspirin n = 354). Between first and second trimesters, aspirin use was not associated with a change in UtA Doppler, placental volume, or vascular flow indices. There was no significant difference in the change in UtA Doppler pulsatility index (PI) Z-scores or notching (PI Z-score -0.2 vs. -0.2, p = 0.17), nor was there a significant change in placental volume Z-score and vascular flow indices (volume Z-score change: 0.74 vs. 0.62, p = 0.34). CONCLUSION: Low-dose aspirin commenced at 11 weeks in low-risk women does not appear to improve uterine and placental perfusion or placental volume. Any perceived effect on uteroplacental vasculature is not reflected in changes in placental volume nor uteroplacental flow as assessed by two-dimensional and 3D ultrasound.

Preeclampsia Prevention Using Routine Versus Screening Test-Indicated Aspirin in Low-Risk Women.

The objective was to evaluate whether routine aspirin 75 mg is more cost-effective than the Fetal Medicine Foundation screen-and-treat approach for preeclampsia prevention in low-risk nulliparous women. A health economic decision analytical model was devised to estimate the discounted net health and cost outcomes of routine aspirin versus Fetal Medicine Foundation screening test-indicated aspirin for a cohort of 100 000 low-risk nulliparous women. Both strategies were compared with no intervention. A subanalysis also compared disaggregated components of the algorithm. The analysis used data from hospital administration, literature, and a randomized controlled trial. Sensitivity analyses assessed the impact of aspirin adherence, test cost, and accuracy on study results. Presumed rates of preeclampsia were 3.75% with no intervention versus 0.45% with aspirin use. Results found that routine aspirin was the preferred strategy, in terms of greater health gains and larger cost savings. It provided 163 quality-adjusted life-years relative to no intervention, whereas the screen-and-treat policy achieved 108 quality-adjusted life-years. Routine aspirin would result in an estimated cost saving of €14.9 million annually relative to no intervention, whereas screen-and-treat approach would result in a smaller cost saving of €3.1 million. When the analysis was extended to consider alternative screen-and-treat strategies, routine aspirin remained the optimally cost-effective approach. In conclusion, routine aspirin use in low-risk nulliparous women has a greater health gain and cost saving compared with both the Fetal Medicine Foundation and other screen-and-treat approaches.

Trial of feasibility and acceptability of routine low-dose aspirin versus Early Screening Test indicated aspirin for pre-eclampsia prevention (TEST study): a multicentre randomised controlled trial.

OBJECTIVE: Evaluate the feasibility and acceptability of routine aspirin in low-risk women, compared with screening-test indicated aspirin for the prevention of pre-eclampsia and fetal growth restriction. DESIGN: Multicentre open-label feasibility randomised controlled trial. SETTING: Two tertiary maternity hospitals in Dublin, Ireland. PARTICIPANTS: 546 low-risk nulliparous women completed the study. INTERVENTIONS: Women underwent computerised randomisation to: Group 1-routine aspirin 75 mg from 11 until 36 weeks; Group 2-no aspirin and; Group 3-aspirin based on the Fetal Medicine Foundation screening test. PRIMARY AND SECONDARY OUTCOME MEASURES: (1) Proportion agreeing to participate; (2) compliance with protocol; (3) proportion where first trimester uterine artery Doppler was obtainable and; (4) time taken to issue a screening result. Secondary outcomes included rates of pre-eclampsia and small-for-gestational-age fetuses. RESULTS: 546 were included in the routine aspirin (n=179), no aspirin (n=183) and screen and treat (n=184) groups. 546 of 1054 were approached (51.8%) and enrolled. Average aspirin adherence was 90%. The uterine artery Doppler was obtained in 98.4% (181/184) and the average time to obtain a screening result was 7.6 (0-26) days. Of those taking aspirin, vaginal spotting was greater; n=29 (15.1%), non-aspirin n=28 (7.9%), OR 2.1 (95% CI 1.2 to 3.6). Postpartum haemorrhage >500 mL was also greater; aspirin n=26 (13.5%), no aspirin n=20 (5.6%), OR 2.6 (95% CI 1.4 to 4.8). CONCLUSION: Low-risk nulliparous women are open to taking aspirin in pregnancy and had high levels of adherence. Aspirin use was associated with greater rates of vaginal bleeding. An appropriately powered randomised controlled trial is now required to address the efficacy and safety of universal low-dose aspirin in low-risk pregnancy compared with a screening approach. TRIAL REGISTRATION NUMBER: ISRCTN (15191778); Post-results.

Should we recommend universal aspirin for all pregnant women?

Low-dose aspirin has been demonstrated to reduce the incidence of preeclampsia and fetal growth restriction in at-risk populations. Its role in low-risk populations is as yet unknown. Novel preeclampsia screening tests are emerging that can predict the risk of the development of preeclampsia from as early as 11 weeks of gestation. It may be more efficacious, acceptable, and cost-effective to prescribe low-dose aspirin to all pregnant women from the first trimester as opposed to performing a screening test in the first instance. There is variation in opinion: the American College of Obstetricians and Gynecologists suggests the use of aspirin only in women who are at risk of preeclampsia, based on patient history; the National Institute for Health and Clinical Excellence, UK, and the US Preventative Services Task Force recommend the use of low-dose aspirin if there is 1 major or 2 moderate risk factors. This point-counterpoint discussion shall address (1) controversies regarding the real impact of low-dose aspirin; (2) controversies in the actual guidelines among the different national societies; (3) controversies regarding emerging preeclampsia screening tests in terms of cost-effectiveness and efficacy, and (4) points in favor of the provision of universal vs screened-positive women.

An open-label randomized-controlled trial of low dose aspirin with an early screening test for pre-eclampsia and growth restriction (TEST): Trial protocol.

OBJECTIVE: Pre-eclampsia remains a worldwide cause of maternal and perinatal morbidity and mortality. Low dose aspirin (LDA) can reduce the occurrence of pre-eclampsia in women with identifiable risk factors. Emerging screening tests can determine the maternal risk of developing placental disease, such as pre-eclampsia from the first trimester of pregnancy. The aim of this study is to determine if it is more beneficial in terms of efficacy and acceptability to routinely prescribe LDA to nulliparous low-risk women compared to test indicated LDA on the basis of a positive screening test for placental disease. METHODS: We propose a three armed multi-center open-labeled randomized control trial of; (i) routine LDA, (ii) no aspirin, and (iii) LDA on the basis of a positive first trimester pre-eclampsia screening test. LDA (75mg once daily) shall be given from the first trimester until 36-week gestation. The primary outcome measures include; (i) the proportion of eligible women that agree to participate (acceptability), (ii) compliance with study protocol (acceptability and feasibility), (iii) the proportion of women in whom it is possible to obtain first trimester trans-abdominal uterine artery Doppler examination (feasibility) and (iv) the proportion of women with a completed screening test that are issued the screening result within one week of having the test performed (feasibility). CONCLUSION: This will be the first clinical trial to determine the efficacy and acceptability in low-risk women of taking routine LDA versus no aspirin versus LDA based on a positive first trimester screening test for the prevention of placental disease.

Fetal anterior abdominal wall thickness in diabetic pregnancy.

OBJECTIVE: The purpose of this study was to investigate whether third trimester fetal anterior abdominal wall (AAW) thickness in diabetic pregnancy reflects glycaemic control and predicts macrosomia. STUDY DESIGN: Prospective cohort study in a tertiary level maternity unit. One hundred and twenty-five diabetic mothers (71 pre-gestational and 54 gestational diabetics on insulin) underwent routine serial third trimester ultrasound examination with the additional measurement of AAW thickness. Pregnancy outcome was obtained. RESULTS: 335 fetal AAW measurements were recorded in diabetic pregnancy from 30 to 38 weeks gestation. Third trimester AAW was significantly higher in macrosomic babies (5.4+/-1.4 mm vs. 4.7+/-1.4 mm, p<0.05). ROC derived cut off for AAW in the prediction of macrosomia was 3.5 mm at 30 weeks, 4.5 mm at 33 weeks and 5.5 mm at 36 weeks gestation. Using either a raised AAW measurement or an AC>90th centile, the prediction of birth weight greater than the 90th centile was better (88%) than with AC alone (70%). This improvement in sensitivity held even at earlier gestations in the third trimester. CONCLUSION: Measurement of AAW in diabetic pregnancy may have a role in the prediction of macrosomia.