Comparing aspirin 75 to 81 mg vs 150 to 162 mg for prevention of preterm preeclampsia: systematic review and meta-analysis.

OBJECTIVE: This study aimed to compare 2 aspirin dosage regimens for the prevention of preterm preeclampsia (PE): 75 to 81 mg vs 150 to 162 mg taken daily starting in the first trimester of pregnancy. DATA SOURCES: A systematic search was performed using PubMed, Embase, CINAHL, Web of Science, and Cochrane Central Register of Controlled Trials from January 1985 to April 2023. STUDY ELIGIBILITY CRITERIA: The inclusion criteria were randomized controlled trials that compared the effect of 2 aspirin dosage regimens during pregnancy for the prevention of PE initiated in the first trimester of pregnancy. The intervention was an aspirin dosage between 150 and 162 mg daily, and the control was an aspirin dosage between 75 and 81 mg daily. METHODS: Of note, 2 reviewers independently screened all citations, selected studies, and evaluated the risk of bias. The review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and applied the Cochrane risk of bias tool. The corresponding authors of the included studies were contacted to validate each of the collected results. The primary outcome was the risk of preterm preeclampsia, and the secondary outcomes included term preeclampsia, any preeclampsia regardless of gestational age, and severe preeclampsia. Relative risks with their 95% confidence interval were calculated for each study and pooled for global analysis. RESULTS: Of note, 4 randomized controlled trials were retrieved involving 552 participants. Moreover, 2 randomized controlled trials were at unclear risk of bias, 1 trial at low risk of bias and 1 trial at high risk of bias, which did not have the information for the primary outcome. The pooled analysis demonstrated that an aspirin dosage of 150 to 162 mg was associated with a significant reduction of preterm preeclampsia, compared with an aspirin dosage of 75 to 81 mg (3 studies; 472 participants; relative risk, 0.34; 95% confidence interval, 0.15-0.79; P=.01; I2=0%). There was no significant effect on the risk of term preeclampsia (3 studies; 472 participants; relative risk, 0.57; 95% confidence interval, 0.12-2.64; P=.48; I2=64%) and all preeclampsia (4 studies; 552 participants; relative risk, 0.42; 95% confidence interval, 0.17-1.05; P=.06; I2=58%), but there was a reduction of severe preeclampsia (3 studies; 472 participantst; RR, 0.23; 95% CI, 0.09-0.62; P=.003; I2=0%). CONCLUSION: When initiated in the first trimester of pregnancy, an aspirin dosage of 150 to 162 mg daily was associated with a lower risk of preterm PE than an aspirin dosage of 75 to 81 mg daily. However, the lack of large, high-quality studies limited the clinical scope of the current results taken alone.

A Pilot Randomized Trial Comparing the Effects of 80 versus 160 mg of Aspirin on Midtrimester Uterine Artery Pulsatility Index in Women with a History of Preeclampsia.

OBJECTIVE: To compare the effects of 80 mg and 160 mg of aspirin, initiated in the first trimester of pregnancy, on mid-trimester uterine artery pulsatility index (UtA-PI) in women with a history of preeclampsia. METHODS: We performed a pilot double-blind randomized controlled trial. Pregnant women with a history of preeclampsia were recruited between 100/7 and 136/7 weeks gestation and randomly assigned to take either 80 or 160 mg of aspirin daily at bedtime from randomization to 356/7 weeks gestation. The primary outcome was mean UtA-PI at 22-24 weeks. Secondary outcomes included the rate of fetal growth restriction and preeclampsia, stratified as term (≥37 weeks), preterm (<37 weeks), and early-onset (<34 weeks) preeclampsia. RESULTS: A total of 107 participants were randomized, including 41 (38%) with a history of preterm preeclampsia and 16 (15%) with a history of early-onset preeclampsia. We observed no significant difference in mean UtA-PI at 22-24 weeks between the 2 groups (0.97; 95% CI 0.88-1.05 vs. 0.97; 95% CI 0.88-1.07, P = 0.9). The rates of fetal growth restriction (8% vs. 2%; P = 0.20); preeclampsia (12% vs. 15%; P = 0.78), preterm preeclampsia (4% vs. 2%; P = 0.56), and early-onset preeclampsia (0% vs. 2%; P = 0.52) were similar in both groups. No serious adverse events associated with the study treatment were reported. CONCLUSION: We observed no significant difference in UtA-PI between the two doses of aspirin, but we observed low rates of fetal growth restriction and preterm and early-onset preeclampsia (all less than 5%). The benefits of aspirin for the prevention of preterm preeclampsia is probably not related to the improvement of deep placentation alone.

Impact of Audits and Multifaceted Intervention on Vaginal Birth After Caesarean: Secondary Analysis of the QUARISMA Trial.

OBJECTIVES: This study estimated the effect that a multifaceted intervention aiming to improve the quality of obstetrical care and reduce Caesarean section (CS) had on the rate of vaginal birth after Caesarean (VBAC). METHODS: This is a secondary analysis of the cluster randomized controlled trial Quality of Care, Obstetrics Risk Management, and Mode of Delivery involving (1) audits regarding the indications for CS, (2) provision of feedback to health professionals, and (3) implementation of best practices to reduce CS rates in Quebec. The impact of intervention on VBAC, trial of labour (TOL), and maternal and neonatal morbidity was reported using adjusted odds ratios (ORs) with 95% confidence intervals (CIs). RESULTS: Out of 105 351 women who delivered during the pre- and postintervention period, 12 493 (11.9%) had a previous CS. We observed no significant impact of the multifaceted intervention on the rates of TOL (adjusted OR 1.22; 95% CI 0.96-1.56, P = 0.11) and VBAC (adjusted OR 1.20; 95% CI 0.97-1.48, P = 0.10) in women with one previous CS. However, the rate of TOL was reduced (adjusted OR 0.38; 95% CI 0.14-0.99) in women with more than one previous CS. The intervention has no influence on maternal and neonatal morbidity. CONCLUSIONS: A multifaceted intervention including audits, feedback to health professionals, and implementation of best practices did not affect VBAC rates or maternal and neonatal morbidity. Our results pointed out the need for decision-making processand risk management tools specific to women with previous CS.

Chronic hypertension: effect of blood pressure control on pregnancy outcome.

OBJECTIVE: To examine whether in patients with CH and mild to moderate hypertension the level of control of blood pressure during pregnancy has a beneficial or adverse effect on the risk of PE or SGA. METHODS: We performed a systematic review and meta-analysis of randomized controlled trials of patients with mild to moderate CH in pregnancy that reported the impact of different levels of control of blood pressure on the risk of PE or SGA. We completed a literature search through PubMed, Embase, Cinahl, Web of science, Cochrane CENTRAL Library Relative risks with random effect were calculated with their 95% confidence intervals (95%CI). RESULTS: Six trials including 495 participants provided data on blood pressure (BP) after entry to the study. Four studies compared antihypertensive agents to no treatment and two studies compared antihypertensive agents to placebo. All trials were conducted between 1976 and 1990 and were considered to be at high risk of bias. There was high heterogeneity between studies for mean arterial pressure (MAP) after randomization (I2 = 87%) and SGA (I2 = 60%), but not for PE (I2 = 0%). There were large differences between studies in the inclusion criteria, antihypertensive regimens, targets of therapy, and gestational age range at entry to the trials. In women receiving antihypertensive therapy, compared to those receiving placebo or no treatment, the MAP after entry to the trial was significantly lower (mean difference -4.2 mmHg, 95%CI -6.6 to -1.8; p = .006). However, there was no significant reduction in the risk of PE (relative risks (RR) 1.03, 95%CI 0.63-1.68; p = .90) or SGA (RR 1.01, 95%CI 0.35-2.93; p = .99). CONCLUSIONS: The findings of the meta-analysis suggest that lowering the blood pressure by antihypertensive medication in women with mild to moderate hypertension in the context of CH has no significant effect on the risk of SGA or PE.

Diet and exercise for preeclampsia prevention in overweight and obese pregnant women: systematic review and meta-analysis.

Objective: To investigate the effect of diet and/or exercise in overweight or obese pregnant women on the risk of preeclampsia (PE). Methods: We performed a systematic review and meta-analysis of randomized controlled trials examining the effect of diet and/or exercise interventions in overweight and obese pregnant women on the risk of PE and hypertensive disorders. We completed a literature search through PubMed, Embase, Cinahl, Web of science, Cochrane CENTRAL Library from their earliest entries to November 2017 and from references of other systematic reviews. No language restrictions were applied. Relative risks (RR) with random effect were calculated with their 95% confidence intervals (CI). Results: There were 23 eligible trials (7236 participants), including 11 (5023 participants) investigating the effect of diet and three (387 participants) investigating the effect of exercise on risk of PE, 14 (4345 participants) investigating the effect of diet, five (884 participants) investigating the effect of exercise and one (304 participants) investigating the effect of diet and exercise on risk of hypertensive disorders. Most studies were considered to be at low risk of bias for random sequence allocation and incomplete outcome data but at high risk of bias for blinding of participant and personnel. The heterogeneity of the studies on PE was low (I2 = 0-11%), but the heterogeneity of the studies on hypertensive disorders was variable (I2 = 0-53%). In women randomized to diet and/or exercise, compared to expectant management, there was no significant difference in the risk of PE (RR 1.01, 95% CI 0.80-1.27; p = .96) or hypertensive disorders of pregnancy (RR 0.87, 95% CI 0.70-1.06; p = .17). In the intervention group, compared to expectant management, gestational weight gain was significantly lower (-1.47 kg, 95% CI -1.97 to -0.97; p < .00001). Metaregression weighted by the size of the studies showed no significant association between gestational weight gain and the risk of PE or hypertensive disorders (p = .314 and p = .124, respectively). Conclusions: Diet and exercise in overweight or obese pregnant women are beneficial in reducing gestational weight gain. However, these interventions do not reduce the risk of PE or hypertensive disorders of pregnancy.

First and Third Trimester Uterine Scar Thickness in Women With Previous Caesarean: A Prospective Comparative Study.

BACKGROUND: Lower uterine segment (LUS) thickness in the third trimester of gestation is associated with the risk of uterine scar defect at delivery. It was suggested that first trimester residual myometrial thickness (RMT) could also predict uterine scar defect at delivery. OBJECTIVE: This study sought to correlate the RMT measured at the site of uterine scar in the first trimester with the LUS thickness measured in the third trimester. METHODS: This was a prospective cohort study of women with a singleton pregnancy and a single prior low-transverse CS. All participants underwent an evaluation of uterine scar by using transvaginal ultrasound at 11 to 13 weeks, including the presence of a scar defect and measurement of RMT; and a second evaluation at 35 to 38 weeks, combining both transvaginal and transabdominal ultrasound, for the measurement of LUS thickness. Spearman's correlation test was used to compare first and third trimester measurements. RESULTS: A total of 166 eligible participants were recruited at mean GA of 12.7 ± 0.5 weeks. We observed an absence of correlation between first trimester RMT and third trimester LUS thickness (correlation coefficient 0.10; P = 0.20). First trimester RMTs below 2.0 mm and below 2.85 mm are poor predictors of third trimester LUS thickness below 2.0 mm (sensitivity, 8% and 23%; specificity, 98% and 87%; positive predictive value, 25% and 14%, respectively). CONCLUSION: There is a poor correlation between first trimester RMT and third trimester LUS thickness in women with a previous CS. First trimester RMT should not be used to inform women on their risk of uterine rupture or to guide clinical management.

Screening for small for gestational age using third-trimester ultrasound markers: protocol for a systematic review and meta-analysis of screening test accuracy.

BACKGROUND: Fetal growth restriction (FGR) is a complication of pregnancy associated with major neonatal morbidity and commonly diagnosed at birth based on birth weight below the 5th or the 10th centile. There is no consensus on the use of routine third-trimester ultrasound for the detection of FGR in a general population. This systematic review aims to estimate the performance of third-trimester ultrasound markers in the screening for babies who are small for gestational age in low-risk or general population. METHODS: A systematic review of screening test accuracy will be conducted. The databases MEDLINE, Embase, Cochrane Library, and Web of Science will be searched from their inception until December 2017, as well as reference lists of included studies and previous related review articles. Studies screening for FGR in a low-risk or general population using third-trimester ultrasound markers and reporting low birth weight for gestational age (small for gestational age at birth) as a reference will be eligible. Two reviewers will independently screen references for inclusion, assess the risk of bias, and extract data. The Quality Assessment of Diagnostic Accuracy Study 2 (QUADAS-2) tool will be used to assess the methodological quality and validity of individual studies. The hierarchal summary receiver operating characteristic and random effects hierarchal bivariate models (Bivariate) will be used to estimate the pooled sensitivity and specificity of each ultrasound marker and to compare the discriminative ability of the different ultrasound markers. Subgroup and sensitivity analyses will be performed to explore the heterogeneity between studies and to assess the effect of screening tests' characteristics (e.g., timing) on their discriminative ability. DISCUSSION: This systematic review will determine the relevance of routine third-trimester ultrasound markers in the screening for FGR in low-risk or general population and their usefulness in standard pregnancy care. Additionally, this knowledge synthesis represents a step in the optimization of the discriminative ability of third-trimester ultrasound and predictive tools, allowing for targeted interventions aiming at the reduction of FGR complications and ultimately improving infants' health. SYSTEMATIC REVIEW REGISTRATION: This protocol has been registered at PROSPERO: international prospective register of systematic reviews. The register number is CRD42018085564 .

Meta-analysis on the effect of aspirin use for prevention of preeclampsia on placental abruption and antepartum hemorrhage.

OBJECTIVE DATA: Impaired placentation in the first 16 weeks of pregnancy is associated with increased risk of subsequent development of preeclampsia, birth of small-for-gestational-age neonates, and placental abruption. Previous studies reported that prophylactic use of aspirin reduces the risk of preeclampsia and small-for-gestational-age neonates with no significant effect on placental abruption. However, meta-analyses of randomized controlled trials that examined the effect of aspirin in relation to gestational age at onset of therapy and dosage of the drug reported that significant reduction in the risk of preeclampsia and small-for-gestational-age neonates is achieved only if the onset of treatment is at ≤16 weeks of gestation and the daily dosage of the drug is ≥100 mg. STUDY: We aimed to estimate the effect of aspirin on the risk of placental abruption or antepartum hemorrhage in relation to gestational age at onset of therapy and the dosage of the drug. STUDY APPRAISAL AND SYNTHESIS METHODS: To perform a systematic review and meta-analysis of randomized controlled trials that evaluated the prophylactic effect of aspirin during pregnancy, we used PubMed, Cinhal, Embase, Web of Science and Cochrane library from 1985 to September 2017. Relative risks of placental abruption or antepartum hemorrhage with their 95% confidence intervals were calculated with the use of random effect models. Analyses were stratified according to daily dose of aspirin (<100 and ≥100 mg) and the gestational age at the onset of therapy (≤16 and >16 weeks of gestation) and compared with the use of subgroup difference analysis. RESULTS: The entry criteria were fulfilled by 20 studies on a combined total of 12,585 participants. Aspirin at a dose of <100 mg per day had no impact on the risk of placental abruption or antepartum hemorrhage, irrespective of whether it was initiated at ≤16 weeks of gestation (relative risk, 1.11; 95% confidence interval, 0.52-2.36) or at >16 weeks of gestation (relative risk, 1.32; 95% confidence interval, 0.73-2.39). At ≥100 mg per day, aspirin was not associated with a significant change on the risk of placental abruption or antepartum hemorrhage, whether the treatment was initiated at ≤16 weeks of gestation (relative risk, 0.62, 95% confidence interval, 0.31-1.26), or at >16 weeks of gestation (relative risk, 2.08; 95% confidence interval, 0.86-5.06), but the difference between the subgroups was significant (P=.04). CONCLUSION: Aspirin at a daily dose of ≥100 mg for prevention of preeclampsia that is initiated at ≤16 weeks of gestation, rather than >16 weeks, may decrease the risk of placental abruption or antepartum hemorrhage.

Aspirin for the prevention of preterm and term preeclampsia: systematic review and metaanalysis.

OBJECTIVE DATA: Metaanalyses of randomized controlled trials have reported contradictory results about the effect of aspirin in the prevention of preeclampsia, both in terms of the gestational age at the onset of treatment and the dose of the drug. The controversy may be resolved by a metaanalysis that includes several recently published trials and particularly the large Combined Multimarker Screening and Randomized Patient Treatment with Aspirin for Evidence-based Preeclampsia Prevention trial and by examination of whether there is a difference of the effect of aspirin on preterm vs term preeclampsia. STUDY: We performed a systematic review and metaanalysis that evaluated the prophylactic effect of aspirin during pregnancy. STUDY APPRAISAL AND SYNTHESIS METHODS: We completed a literature search through PubMed, Cinhal, Embase, Web of Science, and Cochrane library from 1985 to June 2017. Relative risks with random effect were calculated with their 95% confidence intervals. RESULTS: Sixteen trials that included 18,907 participants provided data for preterm and term preeclampsia. Eight of the included studies were evaluated as being of good quality, and the other 8 studies were deemed to be of poor or uncertain quality. There was high heterogeneity within studies (I2 >50%) for preterm and term preeclampsia, but no heterogeneity was found in the subgroup of preterm preeclampsia when the onset of treatment was ≤16 weeks of gestation and the daily dose of aspirin was ≥100 mg (I2=0%). Administration of aspirin was associated with reduction in the risk of preterm preeclampsia (relative risk, 0.62; 95% confidence interval, 0.45-0.87), but there was no significant effect on term preeclampsia (relative risk, 0.92; 95% confidence interval, 0.70-1.21). The reduction in preterm preeclampsia was confined to the subgroup in which aspirin was initiated at ≤16 weeks of gestation and at a daily dose of ≥100 mg (relative risk, 0.33; 95% confidence interval, 0.19-0.57). This effect was also observed in the high-quality studies. The reduction in preterm preeclampsia that was observed in the largest trial (Combined Multimarker Screening and Randomized Patient Treatment with Aspirin for Evidence-based Preeclampsia Prevention; n=1620; relative risk, 0.38; 95% confidence interval, 0.20-0.72) was similar to that in the 5 smaller trials in which aspirin was initiated at ≤16 weeks of gestation and at a daily dose of ≥100 mg (n=639; relative risk, 0.22; 95% confidence interval, 0.07-0.66). CONCLUSION: Aspirin reduces the risk of preterm preeclampsia, but not term preeclampsia, and only when it is initiated at ≤16 weeks of gestation and at a daily dose of ≥100 mg.

Single versus double-layer uterine closure at cesarean: impact on lower uterine segment thickness at next pregnancy.

BACKGROUND: Uterine rupture is a potential life-threatening complication during a trial of labor after cesarean delivery. Single-layer closure of the uterus at cesarean delivery has been associated with an increased risk of uterine rupture compared with double-layer closure. Lower uterine segment thickness measurement by ultrasound has been used to evaluate the quality of the uterine scar after cesarean delivery and is associated with the risk of uterine rupture. OBJECTIVE: To estimate the impact of previous uterine closure on lower uterine segment thickness. STUDY DESIGN: Women with a previous single low-transverse cesarean delivery were recruited at 34-38 weeks' gestation. Transabdominal and transvaginal ultrasound evaluation of the lower uterine segment thickness was performed by a sonographer blinded to clinical data. Previous operative reports were reviewed to obtain the type of previous uterine closure. Third-trimester lower uterine segment thickness at the next pregnancy was compared according to the number of layers sutured and according to the type of thread for uterine closure, using weighted mean differences and multivariate logistic regression analyses. RESULTS: Of 1613 women recruited, with operative reports available, 495 (31%) had a single-layer and 1118 (69%) had a double-layer closure. The mean third-trimester lower uterine segment thickness was 3.3 ± 1.3 mm and the proportion with lower uterine segment thickness <2.0 mm was 10.5%. Double-layer closure of the uterus was associated with a thicker lower uterine segment than single-layer closure (weighted mean difference: 0.11 mm; 95% confidence interval [CI], 0.02 to 0.21 mm). In multivariate logistic regression analyses, a double-layer closure also was associated with a reduced risk of lower uterine segment thickness <2.0 mm (odd ratio [OR], 0.68; 95% CI, 0.51 to 0.90). Compared with synthetic thread, the use of catgut for uterine closure had no significant impact on third-trimester lower uterine segment thickness (WMD: -0.10 mm; 95% CI, -0.22 to 0.02 mm) or on the risk of lower uterine segment thickness <2.0 mm (OR, 0.95; 95% CI, 0.67 to 1.33). Finally, double-layer closure was associated with a reduced risk of uterine scar defect (RR, 0.32; 95% CI, 0.17 to 0.61) at birth. CONCLUSION: Compared with single-layer closure, a double-layer closure of the uterus at previous cesarean delivery is associated with a thicker third-trimester lower uterine segment and a reduced risk of lower uterine segment thickness <2.0 mm in the next pregnancy. The type of thread for uterine closure has no significant impact on lower uterine segment thickness.

Reporting Caesarean Delivery in Quebec Using the Robson Classification System.

OBJECTIVE: The increasing rates of Caesarean sections throughout the world is preoccupant, and a good understanding of which groups of women contribute the most to the CS rate represents an important question in public health. Therefore, we sought to report the CS rate according to the Robson's classification system in the Quebec population. METHOD: We performed a secondary analysis of the QUARISMA database, including all deliveries after 24 weeks' gestation from 32 maternity wards in the province of Quebec between 2008 and 2011 (n = 184 952 deliveries). CS rates were reported according to the modified Robson criteria from The Society of Obstetricians and Gynaecologists of Canada with the relative contribution to the total number of CSs. RESULTS: We observed a global CS rate of 22.9%. Women with previous CS and a fetus in cephalic presentation at term accounted for 35% of all Caesarean deliveries. Nulliparous women with cephalic presentation at term accounted for 30% of all CSs. Among nulliparous women with cephalic presentation, women with spontaneous labour contributed to 12% of all CSs, whereas women with an induction of labour contributed to 16% of all CSs. Non-cephalic fetal presentation accounted for 19% of all CSs. Other indications accounted for the remaining 16% of CSs. CONCLUSION: Most CSs are performed for multiparous women with previous CS; nulliparous women with a cephalic presentation at term, especially those undergoing labour induction; and non-cephalic fetal presentation.

The role of aspirin dose on the prevention of preeclampsia and fetal growth restriction: systematic review and meta-analysis.

BACKGROUND: Preeclampsia and fetal growth restriction are major causes of perinatal death and handicap in survivors. Randomized clinical trials have reported that the risk of preeclampsia, severe preeclampsia, and fetal growth restriction can be reduced by the prophylactic use of aspirin in high-risk women, but the appropriate dose of the drug to achieve this objective is not certain. OBJECTIVE: We sought to estimate the impact of aspirin dosage on the prevention of preeclampsia, severe preeclampsia, and fetal growth restriction. STUDY DESIGN: We performed a systematic review and meta-analysis of randomized controlled trials comparing the effect of daily aspirin or placebo (or no treatment) during pregnancy. We searched MEDLINE, Embase, Web of Science, and Cochrane Central Register of Controlled Trials up to December 2015, and study bibliographies were reviewed. Authors were contacted to obtain additional data when needed. Relative risks for preeclampsia, severe preeclampsia, and fetal growth restriction were calculated with 95% confidence intervals using random-effect models. Dose-response effect was evaluated using meta-regression and reported as adjusted R2. Analyses were stratified according to gestational age at initiation of aspirin (≤16 and >16 weeks) and repeated after exclusion of studies at high risk of biases. RESULTS: In all, 45 randomized controlled trials included a total of 20,909 pregnant women randomized to between 50-150 mg of aspirin daily. When aspirin was initiated at ≤16 weeks, there was a significant reduction and a dose-response effect for the prevention of preeclampsia (relative risk, 0.57; 95% confidence interval, 0.43-0.75; P < .001; R2, 44%; P = .036), severe preeclampsia (relative risk, 0.47; 95% confidence interval, 0.26-0.83; P = .009; R2, 100%; P = .008), and fetal growth restriction (relative risk, 0.56; 95% confidence interval, 0.44-0.70; P < .001; R2, 100%; P = .044) with higher dosages of aspirin being associated with greater reduction of the 3 outcomes. Similar results were observed after the exclusion of studies at high risk of biases. When aspirin was initiated at >16 weeks, there was a smaller reduction of preeclampsia (relative risk, 0.81; 95% confidence interval, 0.66-0.99; P = .04) without relationship with aspirin dosage (R2, 0%; P = .941). Aspirin initiated at >16 weeks was not associated with a risk reduction or a dose-response effect for severe preeclampsia (relative risk, 0.85; 95% confidence interval, 0.64-1.14; P = .28; R2, 0%; P = .838) and fetal growth restriction (relative risk, 0.95; 95% confidence interval, 0.86-1.05; P = .34; R2, not available; P = .563). CONCLUSION: Prevention of preeclampsia and fetal growth restriction using aspirin in early pregnancy is associated with a dose-response effect. Low-dose aspirin initiated at >16 weeks' gestation has a modest or no impact on the risk of preeclampsia, severe preeclampsia, and fetal growth restriction. Women at high risk for those outcomes should be identified in early pregnancy.

Aspirin for the Prevention of Preeclampsia and Intrauterine Growth Restriction.

Low-dose aspirin (LDA) has been used for several years for the prevention of preeclampsia (PE). LDA started in early pregnancy is associated with improvement of placental implantation. The best evidence suggest that LDA can prevent more than half of PE cases in high-risk women when started before 16 weeks of gestation. Moreover, LDA started in early pregnancy reduces the risk of other placenta-mediated complications such as intrauterine growth restriction (IUGR) and perinatal death. The efficacy of LDA has been demonstrated in women with abnormal first-trimester uterine artery Doppler or with prior history of chronic hypertension or preeclampsia.

Low-Dose Aspirin in Early Gestation for Prevention of Preeclampsia and Small-for-Gestational-Age Neonates: Meta-analysis of Large Randomized Trials.

Objectives Meta-analyses of small to moderate size randomized controlled trials (RCTs) suggested that aspirin started before 17 weeks' gestation reduces the risk of preeclampsia and small-for-gestational-age (SGA) neonates. We evaluated data from large randomized trials originally excluded from meta-analyses. Methods We performed meta-analyses of RCTs including more than 350 participants that compared aspirin to placebo during pregnancy. Corresponding authors were contacted to obtain data according to gestational age. Outcomes included preeclampsia, severe preeclampsia, and SGA. Relative risks (RRs) with their 95% confidence intervals (CIs) were calculated. Results Data for women recruited before 17 weeks' gestation were obtained for three (50%) of the six eligible trials for a total of 11,949 participants including 3,293 recruited before 17 weeks' gestation with available data. We observed no impact of low-dose aspirin (60 mg) started before 17 weeks' gestation on the risk of preeclampsia (RR: 0.93; 95% CI: 0.75-1.15), severe preeclampsia (RR: 0.96; 95% CI: 0.71-1.28), or SGA (RR: 0.84; 95% CI: 0.56-1.26) and it was not statistically different than when started at or after 17 weeks' gestation. Conclusion Data from large randomized trials do not support greater benefits of low-dose aspirin (at 60 mg daily) when started before 17 weeks' gestation for the prevention of preeclampsia or SGA.

Prevention of Preeclampsia with Aspirin in Multiple Gestations: A Systematic Review and Meta-analysis.

Objective The objective of this study was to estimate the effect of low-dose aspirin in multiple gestations to prevent preeclampsia and small for gestational age (SGA) neonates. Methods A systematic review and meta-analysis were performed through electronic database searches. Randomized controlled trials (RCTs) of women with multiple gestations assigned to receive aspirin or placebo or no treatment were included. Outcomes included preeclampsia (mild and severe) and SGA neonates. Relative risks (RR) with their 95% confidence intervals (CI) were calculated. Result Out of 6,853 citations, 6 RCTS, including 898 pregnancies, were included. We observed a significant reduction in the risk of preeclampsia (RR, 0.67; 95% CI, 0.48-0.94) and mild preeclampsia (RR, 0.44; 95% CI, 0.24-0.82) but not severe preeclampsia (RR, 1.02; 95% CI, 0.61-1.72) with low-dose aspirin. The risk of SGA was not changed (RR, 1.09; 95% CI, 0.80-1.47). The reduction of preeclampsia was not different between women randomized before (RR, 0.86; 95% CI, 0.41-1.81) or after 16 weeks' gestation (RR, 0.64; 95% CI, 0.43-0.96) (p = 0.50). Conclusion There is low level of evidence supporting the use of low-dose aspirin for the prevention of preeclampsia and SGA neonates in multiple gestations.

Labor Dystocia and the Risk of Uterine Rupture in Women with Prior Cesarean.

Objective The objective of this study was to evaluate the association between labor dystocia and uterine rupture. Methods We performed a secondary analysis of a multicenter case-control study that included women with single, prior, low-transverse cesarean section who experienced complete uterine rupture during a trial of labor (TOL). For each case, three women who underwent a TOL without uterine rupture were selected as controls. Data were collected on cervical dilatations from admission to delivery. We evaluated the relationship between uterine rupture and labor dystocia according to several criteria, including the World Health Organization's (WHO's) partogram. Results Data were available for 90 cases and 260 controls. Compared with the controls, uterine rupture was associated with less cervical dilatation on admission, slower cervical dilatation in the first stage of labor and longer second stage of labor (all with p < 0.05). Performing cesarean when the labor curve crossed the ACTION line of WHO's partogram or when the second stage was greater than 2 hours could have (1) prevented up to 56% of uterine rupture and (2) reduced the duration of labor in 57% of women with failed TOL. Conclusion Labor dystocia is a significant risk factor for uterine rupture. Labor progression should be assessed regularly in women with prior cesarean.