Low-dose Aspirin For Prevention Research Articles

Reconsidering the effectiveness of low-dose aspirin in prevention of pre-eclampsia among otherwise low risk twin gestations: A historical cohort study.

To investigate the effectiveness of low-dose aspirin (LDA) in the prevention of pre-eclampsia (PE) among otherwise low-risk twin gestations. A historical cohort study consisting of all pregnant individuals with dichorionic diamniotic (DCDA) twin pregnancy who delivered between 2014 and 2020. Patients treated with LDA were matched by a 1:4 ratio to individuals who were not treated with LDA by age, body mass index and parity. During the study period, 2271 individuals carrying DCDA pregnancies delivered at our center. Of these, 404 were excluded for one or more additional major risk factors. The remaining cohort consisted of 1867 individuals of whom 142 (7.6%) were treated with LDA and were compared with a 1:4 matched group of 568 individuals who were not treated. The rate of preterm PE did not differ significantly between the two groups (18 [12.7%] in the LDA group vs. 55 [9.7%] in the no-LDA group; P= 0.294, adjusted odds ratio 1.36, 95% confidence interval 0.77-2.40). There were no other significant between-group differences. Low-dose aspirin treatment in pregnant individuals with DCDA twin gestations without additional major risk factors was not associated with a reduction in the rate of preterm PE.

Aspirin for the Prevention of Early and Severe Pre-Eclampsia Recurrence: A Real-World Population-Based Study.

Many clinical trials have reported that low-dose aspirin decreases the risk of pre-eclampsia in women with prior pre-eclampsia. However, its impact in a real-world population has not been fully assessed. To assess the rates of low-dose aspirin initiation during pregnancy in women with a history of pre-eclampsia, and to evaluate the impact of low-dose aspirin in prevention of pre-eclampsia recurrence in a real-world population. CONCEPTION is a French nationwide cohort study which uses data from the country's National Health Data System database. We included all women in France who gave birth at least twice between 2010-2018, and who had pre-eclampsia during their first pregnancy. Every dispensing of low-dose aspirin (75-300 mg) between the beginning of their second pregnancy and 36 weeks of gestation (WG) was identified. We used Poisson regression models to estimate the adjusted incidence rate ratios (aIRRs) of receiving aspirin at least once during their second pregnancy. In women who had early and/or severe pre-eclampsia during their first pregnancy, we estimated the IRRs of pre-eclampsia recurrence during their second pregnancy according to the aspirin therapy. In 28,467 women who were included in the study, the aspirin initiation rate during the second pregnancy ranged from 27.8% for women in whose first pregnancy the pre-eclampsia was mild and late, to 79.9% for those women whose pre-eclampsia was severe and early. Just over half (54.3%) of those treated with aspirin-initiated treatment before 16 WG and adhered to treatment. Compared with women with mild and late pre-eclampsia, the aIRRs (95% CI) for receiving aspirin at least once during the second pregnancy were 1.94 (1.86-2.03) for women with severe and late pre-eclampsia, 2.34 (2.17-2.52) for those with early and mild pre-eclampsia, and 2.87 [2.74-3.01] for those with early and severe pre-eclampsia E. Social deprivation was associated with a lower initiation of aspirin (IRR = 0.74 [0.70-0.78]). Aspirin was not associated with a lower risk of mild and late pre-eclampsia, severe and late pre-eclampsia, or mild and early pre-eclampsia during the second pregnancy. The aIRRs for severe and early pre-eclampsia during the second pregnancy were 0.77 (0.62-0.95) for women who received prescribed aspirin at least once, 0.71 (0.5-0.89) for those who initiated aspirin therapy before 16 WG, and 0.60 (0.47-0.77) for those who adhered to aspirin treatment throughout their second pregnancy. The risk of severe and early pre-eclampsia was lower only when the prescribed mean daily dose was ≥ 100 mg/day. In women with a history of pre-eclampsia, aspirin initiation during a second pregnancy and adherence to the prescribed dosage were largely insufficient, especially for women experiencing social deprivation. Aspirin initiated before 16 WG at a dose ≥ 100 mg/day was associated with a lower risk of severe and early pre-eclampsia.

Effectiveness of Low Dose Aspirin for Prevention of Preeclampsia in a Private Hospital Setting

Effectiveness of Low Dose Aspirin for Prevention of Preeclampsia in a Private Hospital Setting

Health care workers and key policy informant's knowledge of the use of calcium and low dose aspirin for prevention of preeclampsia in Malawian women.

This study investigated health care workers and key policy informant's knowledge, and barriers to the use of calcium and aspirin for preventing preeclampsia in Blantyre and Lilongwe, Malawi. A descriptive cross-sectional formative study using semi-structured In-Depth Interview (IDIs) was conducted at Queen Elizabeth Central Hospital (QECH), Reproductive Health Directorate, and the United Nations Population Development Fund (UNFPA) Office in 2021. Data was analyzed using NVIVO™ software. Thematic content analysis was used to analyze and interpret the findings. Emerging themes were then developed inductively and deductively. Doctors had greater knowledge of the use of calcium and aspirin for prevention of preeclampsia compared to nurses and key policy informants. Lack of knowledge, patient's late presentation, scarcity of calcium tablets and delays in implementing new guidelines were the barriers to use identified. This study shows that there are health care worker and policy level barriers that affect the implementation of calcium and aspirin use for the prevention of preeclampsia in Malawian women.

A randomized controlled trial of low-dose aspirin for the prevention of preeclampsia in women at high risk in China

Low-dose aspirin has been the most widely studied preventive drug for preeclampsia. However, guidelines differ considerably from country to country regarding the prophylactic use of aspirin for preeclampsia. There is limited evidence from large trials to determine the effect of 100 mg of aspirin for preeclampsia screening in women with high-risk pregnancies, based on maternal risk factors, and to guide the use of low-dose aspirin in preeclampsia prevention in China. The Low-Dose Aspirin in the Prevention of Preeclampsia in China study was designed to evaluate the effect of 100 mg of aspirin in preventing preeclampsia among high-risk pregnant women screened with maternal risk factors in China, where preeclampsia is highly prevalent, and the status of low-dose aspirin supply is commonly suboptimal. We conducted a multicenter randomized controlled trial at 13 tertiary hospitals from 11 provinces in China between 2016 and 2019. We assumed that the relative reduction in the incidence of preeclampsia was at least 20%, from 20% in the control group to 16% in the aspirin group. Therefore, the targeted recruitment number was 1000 participants. Women were randomly assigned to the aspirin or control group in a 1:1 allocation ratio. Statistical analyses were performed according to an intention-to-treat basis. The primary outcome was the incidence of preeclampsia, diagnosed along with a systolic blood pressure of ≥140 mm Hg or a diastolic blood pressure of ≥90 mm Hg after 20 weeks of gestation, with a previously normal blood pressure (systolic blood pressure of <140 mm Hg and diastolic blood pressure of <90 mm Hg), and complicated by proteinuria. The secondary outcomes included maternal and neonatal outcomes. Logistic regression analysis was used to determine the significance of difference of preeclampsia incidence between the groups for both the primary and secondary outcomes. Interaction analysis was also performed. A total of 1000 eligible women were recruited between December 2016 and March 2019, of which the final 898 patients were analyzed (464 participants in the aspirin group, 434 participants in the control group) on an intention-to-treat basis. No significant difference was found in preeclampsia incidence between the aspirin group (16.8% [78/464]) and the control group (17.1% [74/434]; relative risk, 0.986; 95% confidence interval, 0.738-1.317; P=.924). Likewise, adverse maternal and neonatal outcomes did not differ significantly between the 2 groups. Meanwhile, the incidence of postpartum hemorrhage between the 2 groups was similar (6.5% [30/464] in the aspirin group and 5.3% [23/434] in the control group; relative risk, 1.220; 95% confidence interval, 0.720-2.066; P=.459). We did not find any significant differences in preeclampsia incidence between the 2 groups in the subgroup analysis of the different risk factors. A dosage of 100 mg of aspirin per day, initiated from 12 to 20 gestational weeks until 34 weeks of gestation, did not reduce the incidence of preeclampsia in pregnant women with high-risk factors in China.

Sildenafil plus Low Dose Aspirin for Prevention of Preeclampsia: A Randomized Controlled Trial

Objective: To compare between the efficacy of the use of oral sildenafil plus low dose aspirin versus the use of oral low dose aspirin alone in pregnancy as preventive measure in women at risk for preeclampsia (PE). Design: A randomized clinical trial. Setting: Outpatient Obstetric clinic of Ain Shams University Maternity Hospital. Population or sample: Women at gestational age of ≤16 weeks who at risk for PE between June 2018 and June 2019. Methods: Participants were randomly allocated into two groups: Group I Included 200 women who received a 25 mg tablet of oral sildenafil citrate tid until delivery plus 100 mg tablet of aspirin orally once daily until gestational age of 36 weeks, Group II Included 200 women who received a 100 mg tablet of aspirin orally once daily until gestational age of 36 weeks. Main Outcome Measures: Incidence of preeclampsia diagnosed per ACOG criteria. Results: The incidence of PE in both groups showed no statistically significant difference. The incidence of PE in the first group is 11.0%, and it is 12.0% in the second group (p-value 0.754). Conclusion: The addition of sildenafil citrate to low dose aspirin had no impact on the prevention of preeclampsia for women at risk of PE, in addition, sildenafil did not improve maternal and fetal outcomes.

Low Dose Aspirin in prevention of Spontaneous Preterm Birth in Suez Canal University Hospital

Low Dose Aspirin in prevention of Spontaneous Preterm Birth in Suez Canal University Hospital

Low-dose Aspirin for Prevention of Adverse Pregnancy Outcomes in Twin Pregnancies

Low-dose Aspirin for Prevention of Adverse Pregnancy Outcomes in Twin Pregnancies

Impact of ACOG Guideline Regarding Low Dose Aspirin for Prevention of Superimposed Preeclampsia [27O

INTRODUCTION: In July 2016, an American College of Obstetricians and Gynecologists (ACOG) guideline recommended that pregnant women with chronic hypertension (CHTN) be offered low dose aspirin to prevent superimposed preeclampsia (SIP). This study aimed to evaluate the incidence of SIP in women with CHTN before and after the ACOG guideline. METHODS: This retrospective cohort study included CHTN patients who delivered at Thomas Jefferson University Hospital from 1/2008 to 7/2017, excluding multiple gestations. The cohort was divided into 2 groups, before and after the ACOG recommendation. We offered daily 81 mg aspirin. The cohort was stratified by other risk factors for SIP, including history of preeclampsia and pre-gestational diabetes. The primary outcome was incidence of SIP. Secondary outcomes were incidence of SIP with severe features (SIPSF), small for gestational age, and preterm birth. RESULTS: We identified 715 pregnant CHTN patients, comprised of 80 post-ACOG and 635 pre-ACOG patients. The incidence of SIP in all women with CHTN was 20 (25%) vs 232 (37%), OR 0.43 (95% CI 0.26-0.73). SIP and SIPSF were significantly decreased in the subgroup of women with CHTN without other risk factors: 4/41 (10%) vs 106/355 (30%), OR 0.25 (95% CI 0.08-0.73); and 2/41 (5%) vs 65/355 (18%), OR 0.22 (95% CI 0.54-0.97), respectively. Maternal demographics and secondary outcomes were not significantly different. CONCLUSION: After the ACOG guideline, low dose aspirin decreased SIP by 57% in all women with CHTN. The benefit was higher in women with CHTN without other risk factors, with decreases of 75% in SIP and 78% in SIPSF.

Bleeding Risk with Long-Term Low-Dose Aspirin: A Systematic Review of Observational Studies.

BackgroundLow-dose aspirin has proven effectiveness in secondary and primary prevention of cardiovascular events, but is also associated with an increased risk of major bleeding events. For primary prevention, this absolute risk must be carefully weighed against the benefits of aspirin; such assessments are currently limited by a lack of data from general populations.MethodsSystematic searches of Medline and Embase were conducted to identify observational studies published between 1946 and 4 March 2015 that reported the risks of gastrointestinal (GI) bleeding or intracranial hemorrhage (ICH) with long-term, low-dose aspirin (75–325 mg/day). Pooled estimates of the relative risk (RR) for bleeding events with aspirin versus non-use were calculated using random-effects models, based on reported estimates of RR (including odds ratios, hazard ratios, incidence rate ratios and standardized incidence ratios) in 39 articles.FindingsThe incidence of GI bleeding with low-dose aspirin was 0.48–3.64 cases per 1000 person-years, and the overall pooled estimate of the RR with low-dose aspirin was 1.4 (95% confidence interval [CI]: 1.2–1.7). For upper and lower GI bleeding, the RRs with low-dose aspirin were 2.3 (2.0–2.6) and 1.8 (1.1–3.0), respectively. Neither aspirin dose nor duration of use had consistent effects on RRs for upper GI bleeding. The estimated RR for ICH with low-dose aspirin was 1.4 (1.2–1.7) overall. Aspirin was associated with increased bleeding risks when combined with non-steroidal anti-inflammatory drugs, clopidogrel and selective serotonin reuptake inhibitors compared with monotherapy. By contrast, concomitant use of proton pump inhibitors decreased upper GI bleeding risks relative to aspirin monotherapy.ConclusionsThe risks of major bleeding with low-dose aspirin in real-world settings are of a similar magnitude to those reported in randomized trials. These data will help inform clinical judgements regarding the use of low-dose aspirin in prevention of cardiovascular events.

Effect of aspirin in prevention of adverse pregnancy outcome in women with elevated alpha-fetoprotein

Background: To evaluate the effect of low-dose aspirin in prevention of adverse pregnancy outcomes (APO) in women with second trimester alpha-fetoprotein (AFP) >2.5 multiple of median (MOM) and to compare aspirin effect on women with normal and abnormal uterine artery (UtA) Doppler. The primary outcome was the adverse pregnancy outcome.Methods: This randomized controlled trial was conducted in singleton pregnant women, who had unexplained AFP >2.5 MOM and gestational age between 15 and 18 weeks of gestation. They were assigned randomly to receive either aspirin (N = 65) or control (N = 68). UtA Doppler velocimetry studies were performed at the time of targeted ultrasonographic exam.Results: Two groups were comparable regarding the maternal characteristics. The frequency of APO in aspirin and control groups were 26.1% versus 44.1% (p = 0.045), the frequency of preterm delivery before 34 weeks were 3.2% versus 22.0% in aspirin and control group, p = 0.001. Other outcomes were similar in both groups. The frequency of adverse outcomes in women with abnormal UtA Doppler was 39.1% in aspirin and 60.0% in control group, p = 0.556.Conclusion: Low-dose aspirin reduces APO and delivery before 34 weeks of gestation in pregnant women with unexplained elevated AFP.

Low Dose Aspirin in Preeclampsia – History Revisited

Objectives: To study the role of low-dose aspirin in prevention of pre-eclampsia .and its effect on maternal & neonatal outcome. DESIGN: A prospective randomized double-blind placebo controlled study. METHODS: All the high risk antenatal women presenting between 12–24 weeks of gestation were randomized to receive either aspirin 75 mg/day or matching placebo. Both the groups were compared for pre-eclampsia, pregnancy duration, birthweight, adverse maternal or neonatal outcome. RESULTS: A total of 120 women were followed up. The incidence of pre-eclampsia in aspirin group was 0.83% ,whereas none of the patients developed preeclampsia in placebo group. There were no significant differences between both the groups in. number of preterm delivery 11.47% in aspirin group vs 22% in placebo group, of SGA babies 16.9% vs 17.2% in placebo group. Aspirin was also not associated with increased risk of maternal or fetal complications. CONCLUSIONS: : The results of present study do not support the use of low dose aspirin for prevention of pre-eclampsia or its complications in any category of high risk women as proven by results of previous large scale trials and further multicentric large trials are still required to assess the role.

ASPIRIN ADMINISTRATION FOR PREVENTION OF ADVERSE PREGNANCY OUTCOMES

The prophylactic use of low-dose aspirin for prevention of preeclampsia has been an important research question in obstetrics for the last three decades. In 1979, Crandon and Isherwood observed that nulliparous women who had taken aspirin regularly during pregnancy were less likely to have preeclampsia than women who did not. In 1985, Beaufils et al published the first randomized trial suggesting that 150 mg aspirin and 300 mg dipyridamole daily from 3 months’ gestation onwards decreased the risk of preeclampsia, fetal growth restriction and stillbirth in high-risk women. Subsequently, more than 50 trials have been carried out throughout the world and a meta-analysis of these studies reported that the administration of low-dose aspirin in high-risk pregnancies is associated with a decrease in the rate of preeclampsia by approximately 10%. Consequently, several national professional bodies recommend that high-risk pregnancies should be treated with aspirin (50–150 mg daily).

A meta-analysis of low-dose aspirin for prevention of preeclampsia

Low-dose aspirin (LDA) is widely used for prevention of preeclampsia. However, conflicting results have been obtained from various studies. The aim of our study was to evaluate the effect of LDA in prevention of preeclampsia in high-risk and low-risk women. A total of 19 randomized control trials were identified using PUBMED search engine and Cochrane Clinical Trial register. The study population was divided into high-risk and low-risk groups. The effect measured was incidence of preeclampsia in women taking either LDA or placebo where the relative risk (RR) and the 95% confidence interval (CI) were calculated for both groups. A total of 28237 women were studied, out of which 16550 were in the low-risk group while 11687 were in the high-risk group. The overall incidence of preeclampsia was 7.4%. With the aspirin group it was 6.9% while in the placebo group it was 7.8%. In the high-risk group there was 21% reduction in the risk of preeclampsia associated with the use of aspirin (RR 0.79, 95% CI 0.65-0.97). However, LDA is not effective in reducing the risk in low-risk population (RR 0.86, 95% CI 0.64-1.17). LDA has a small effect in the prevention of preeclampsia in women considered to be at high risk for the disease. However, it is not effective in reducing the risk in the low-risk group.

591: Low-dose aspirin for prevention of preeclampsia and its complications: a cost-effectiveness analysis

591: Low-dose aspirin for prevention of preeclampsia and its complications: a cost-effectiveness analysis

Aspirin and Other Platelet-Active Drugs: The Relationship Among Dose, Effectiveness, and Side Effects

Aspirin and Other Platelet-Active Drugs: The Relationship Among Dose, Effectiveness, and Side Effects

Prevention of Pregnancy‐Induced Hypertension in Twins by Early Administration of Low‐Dose Aspirin: A Preliminary Report

Effectiveness of early administered low-dose aspirin in prevention of pregnancy-induced hypertension (PIH) and fetal growth retardation in twin pregnancies was investigated in a randomized placebo controlled, double-blind trial in 47 twin pregnancies. Twenty-four women received 100 mg of aspirin daily from mean gestational age of 17.7 wk, and 23 women ingested placebo from a mean gestational age of 18 wk until delivery. The placebo and aspirin group were similar in age, weight gain, zygosity, gravidity, parity, and obstetrical antecedents. Treatment lasted for a mean period of 16.8 wk and 18.3 wk in the placebo and aspirin groups, respectively. The mean gestational age at birth was 35.0 wk and 36.4 wk in the placebo and aspirin groups, respectively. PIH was noted in six women (26%) in the placebo group, but in only one woman (4%) in the aspirin treated patients (P < .05). The mean combined fetal weights of both twins, and the mean weight of the second twin at delivery were significantly higher in the aspirin treated mothers than in the placebo treated gravidas (mean difference of 781 g, P < .02 and mean difference of 488 g, P < .005, respectively). Intrauterine growth retardation (< 10th percentile) concerned 11 (24%) and six (13%) fetuses in the placebo and aspirin groups, respectively. No adverse effects of treatment to either the mothers or the infants were noted. Low-dose aspirin reduces the incidence of PIH and has a beneficial effect on fetal growth in twin pregnancies. Additional clinical trials are needed in order to define and select subgroups of twins where aspirin treatment is recommended.

Low-dose aspirin in prevention and treatment of intrauterine growth retardation and pregnancy-induced hypertension

International Journal of Gynecology & ObstetricsVolume 43, Issue 1 p. 91-91 Citations from the literature diseases in pregnancy Low-dose aspirin in prevention and treatment of intrauterine growth retardation and pregnancy-induced hypertension F. Parazzini, F. ParazziniSearch for more papers by this authorC. Benedetto, C. BenedettoSearch for more papers by this authorT. Frusca, T. FruscaSearch for more papers by this authorG. Gregorini, G. GregoriniSearch for more papers by this authorL. Bocciolone, L. BoccioloneSearch for more papers by this authorL. Marozio, L. MarozioSearch for more papers by this authorM. Romero, M. RomeroSearch for more papers by this authorV. Danesino, V. DanesinoSearch for more papers by this authorG. De Gaetano, G. De GaetanoSearch for more papers by this authorA. Gastaldi, A. GastaldiSearch for more papers by this authorM. Massobrio, M. MassobrioSearch for more papers by this authorG. Remuzzi, G. RemuzziSearch for more papers by this authorG. Tognoni, G. TognoniSearch for more papers by this authorS. Guaschino, S. GuaschinoSearch for more papers by this authorC. Bianchi, C. BianchiSearch for more papers by this authorA. Valcamonico, A. ValcamonicoSearch for more papers by this authorM. Giambuzzi, M. GiambuzziSearch for more papers by this authorD. Ammendola, D. AmmendolaSearch for more papers by this authorF. Casucci, F. CasucciSearch for more papers by this author F. Parazzini, F. ParazziniSearch for more papers by this authorC. Benedetto, C. BenedettoSearch for more papers by this authorT. Frusca, T. FruscaSearch for more papers by this authorG. Gregorini, G. GregoriniSearch for more papers by this authorL. Bocciolone, L. BoccioloneSearch for more papers by this authorL. Marozio, L. MarozioSearch for more papers by this authorM. Romero, M. RomeroSearch for more papers by this authorV. Danesino, V. DanesinoSearch for more papers by this authorG. De Gaetano, G. De GaetanoSearch for more papers by this authorA. Gastaldi, A. GastaldiSearch for more papers by this authorM. Massobrio, M. MassobrioSearch for more papers by this authorG. Remuzzi, G. RemuzziSearch for more papers by this authorG. Tognoni, G. TognoniSearch for more papers by this authorS. Guaschino, S. GuaschinoSearch for more papers by this authorC. Bianchi, C. BianchiSearch for more papers by this authorA. Valcamonico, A. ValcamonicoSearch for more papers by this authorM. Giambuzzi, M. GiambuzziSearch for more papers by this authorD. Ammendola, D. AmmendolaSearch for more papers by this authorF. Casucci, F. CasucciSearch for more papers by this author First published: October 1993 https://doi.org/10.1016/0020-7292(93)90287-7Citations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume43, Issue1October 1993Pages 91-91 RelatedInformation

Low-Dose Aspirin in Prevention and Treatment of Intrauterine Growth Retardation and Pregnancy-Induced Hypertension

Low-Dose Aspirin in Prevention and Treatment of Intrauterine Growth Retardation and Pregnancy-Induced Hypertension

Low-dose aspirin in prevention and treatment of intrauterine growth retardation and pregnancy-induced hypertension

Meta-analysis of data from several controlled trials has shown that low-dose aspirin reduces the risk of pregnancy-induced hypertension (PIH) and intrauterine growth retardation (IUGR) in women at high risk of these disorders. We have assessed the efficacy of low-dose aspirin in women judged to be at moderate risk.Women were included on prophylactic criteria— age under 18 or over 40 years, mild or moderate chronic hypertension (diastolic pressure between 90 and 110 mm Hg), nephropathy with normal renal function and blood pressure, history of PIH or IUGR, and twin pregnancy—or therapeutic criteria—PIH or early signs of IUGR in current pregnancy. Eligible women were randomly assigned treatment with 50 mg aspirin daily until delivery (583) or no treatment (523); 18 and 46 women, respectively, were lost to follow-up. The groups were well matched for baseline characteristics. We found no differences between the no-treatment and aspirin groups in numbers of spontaneous (5 vs 2) or therapeutic (1 vs2) abortions, stillbirths (14 vs 13), perinatal mortality (35·7 vs 28·6 per 1000 births), mean birthweight (2858 [SD 729] vs 2874 [795] g), proportion of infants with birthweights below the 10th centile (95 [18·3%] vs 117 [19·0%]), or births before 37 weeks' gestation (184 [35·6%] vs 209 [33·9%]). Nor did the groups differ in the frequency of PIH with or without proteinuria (51 [15·2%] vs 81 [19·3%]). There was no difference in mean birthweight between the treatment groups in separate analyses according to criteria for trial entry and week of gestation at randomisation.Our study gives little support to the notion that low-dose aspirin is beneficial in women at moderate risk of PIH or IUGR.