Pekka Taipale

Aspirin in the prevention of pre‐eclampsia in high‐risk women: a randomised placebo‐controlled PREDO Trial and a meta‐analysis of randomised trials

Objective  To study the effect of aspirin in the prevention of pre‐eclampsia in high‐risk women.

Vasoactive agents for the prediction of early- and late-onset preeclampsia in a high-risk cohort.

BackgroundTo evaluate the soluble fms-like tyrosine kinase-1 (sFlt-1), placental growth factor (PlGF), and sFlt-1/PlGF ratio for the prediction of early- and late-onset preeclampsia in a high-risk cohort.MethodsWe studied serial serum samples collected prospectively at 12 + 0 - 14 + 0, 18 + 0 - 20 + 0, and 26 + 0 - 28 + 0 weeks + days of gestation in 6 women who developed early-onset preeclampsia (before 34 weeks of gestation) and in 21 women who developed late-onset preeclampsia (after 34 weeks of gestation) with automated ElecSys 2010 immunoanalyzer (Roche Diagnostics, Germany). Twenty-six high-risk women and 53 women without risk factors with normal pregnancies served as controls.ResultsSerum PlGF concentrations were lower at 18 + 0 to 20 + 0, and 26 + 0 to 28 + 0 weeks of gestation in women who developed early-onset preeclampsia compared to women who developed late-onset preeclampsia and to controls (p < 0.05 for all comparisons). At 18 + 0 to 20 + 0 weeks of gestation area under the receiver-operating characteristic curve (AUC) for serum PlGF was 99.8% (p = 0.0007, 95% CI 99.0-100.0). At 26 + 0 to 28 + 0 weeks of gestation serum sFlt-1/PlGF ratio explicitly detects those women who developed early-onset preeclampsia (AUC 100.0%, p = 0.0007, 95% CI 100–100). Amongst women with late-onset preeclampsia, those who developed severe form of the disease (N = 8) had significantly higher serum sFlt-1 concentrations at all three timepoints (p = 0.004, p = 0.006, and p = 0.003, respectively) compared to women with non-severe form (N = 13).ConclusionsLow serum PlGF concentration predicts early-onset preeclampsia from the second trimester and elevated serum sFlt-1/PlGF ratio from 26 to 28 weeks of gestation. Elevated serum sFlt-1 concentration in the first trimester in women who later develop late-onset, severe preeclampsia may suggest different etiology compared to the late-onset non-severe form of the disease.

Cluster analysis to estimate the risk of preeclampsia in the high-risk Prediction and Prevention of Preeclampsia and Intrauterine Growth Restriction (PREDO) study

Objectives Preeclampsia is divided into early-onset (delivery before 34 weeks of gestation) and late-onset (delivery at or after 34 weeks) subtypes, which may rise from different etiopathogenic backgrounds. Early-onset disease is associated with placental dysfunction. Late-onset disease develops predominantly due to metabolic disturbances, obesity, diabetes, lipid dysfunction, and inflammation, which affect endothelial function. Our aim was to use cluster analysis to investigate clinical factors predicting the onset and severity of preeclampsia in a cohort of women with known clinical risk factors. Methods We recruited 903 pregnant women with risk factors for preeclampsia at gestational weeks 12+0–13+6. Each individual outcome diagnosis was independently verified from medical records. We applied a Bayesian clustering algorithm to classify the study participants to clusters based on their particular risk factor combination. For each cluster, we computed the risk ratio of each disease outcome, relative to the risk in the general population. Results The risk of preeclampsia increased exponentially with respect to the number of risk factors. Our analysis revealed 25 number of clusters. Preeclampsia in a previous pregnancy (n = 138) increased the risk of preeclampsia 8.1 fold (95% confidence interval (CI) 5.7–11.2) compared to a general population of pregnant women. Having a small for gestational age infant (n = 57) in a previous pregnancy increased the risk of early-onset preeclampsia 17.5 fold (95%CI 2.1–60.5). Cluster of those two risk factors together (n = 21) increased the risk of severe preeclampsia to 23.8-fold (95%CI 5.1–60.6), intermediate onset (delivery between 34+0–36+6 weeks of gestation) to 25.1-fold (95%CI 3.1–79.9) and preterm preeclampsia (delivery before 37+0 weeks of gestation) to 16.4-fold (95%CI 2.0–52.4). Body mass index over 30 kg/m2 (n = 228) as a sole risk factor increased the risk of preeclampsia to 2.1-fold (95%CI 1.1–3.6). Together with preeclampsia in an earlier pregnancy the risk increased to 11.4 (95%CI 4.5–20.9). Chronic hypertension (n = 60) increased the risk of preeclampsia 5.3-fold (95%CI 2.4–9.8), of severe preeclampsia 22.2-fold (95%CI 9.9–41.0), and risk of early-onset preeclampsia 16.7-fold (95%CI 2.0–57.6). If a woman had chronic hypertension combined with obesity, gestational diabetes and earlier preeclampsia, the risk of term preeclampsia increased 4.8-fold (95%CI 0.1–21.7). Women with type 1 diabetes mellitus had a high risk of all subgroups of preeclampsia. Conclusion The risk of preeclampsia increases exponentially with respect to the number of risk factors. Early-onset preeclampsia and severe preeclampsia have different risk profile from term preeclampsia.

Aspirin in the prevention of pre-eclampsia in high-risk women.

Sir, We thank Dr Thornton for his interest in our article ‘Aspirin in the prevention of pre-eclampsia in high-risk women’ published in the January 2013 issue ofBJOG. He raises four points we would like to respond to: the strength of effect; sample size; exclusion of participants from the main analysis; and trial registration. Dr Thornton concludes the commentary by writing that the effect of aspirin we reported in the meta-analysis for women who also have abnormal uterine artery Doppler waveforms at 14 weeks of gestation differs little from its effect in other high-risk groups. We have difficulty in agreeingwith this; in our opinion the risk ratio in our meta-analysis (RR 0.55; 95% CI 0.37–0.83) differs from those reported by theCochrane review. The differences are even better encapsulated by comparing the numbers needed to treat (NNTs). In our meta-analysis, the substantial reduction in risk together with the high initial risk (36%) resulted in an NNT of six for preventing preeclampsia, whereas the Cochrane review reported an NNT for pre-eclampsia of 19 for women at high risk (20% risk) and 119 for women at moderate risk (6%), and concluded that ‘further information is required to assess which women are most likely to benefit, when treatment is best started, and at what dose’. The PARIS meta-analysis reported a 10% reduction and an NNT of 56 for women at high risk (18% risk) and 167 for women at moderate risk (6%). In other respects our study represents both the strengths and weaknesses of clinician-initiated trials. With limited funding, from non-commercial sources only, the participating clinicians in ten centres were able to screen 947 women whose history indicated an increased risk of pre-eclampsia, to find those whose uterine artery flow indicates a particularly high risk. As we discuss in the article, in hindsight the criterion chosen was too strict, and only 152women could be randomised. Although Dr Thornton is correct in stating that 31 of these women discontinued the treatment for various reasons and were excluded from the main analysis, he seems to overlook our description of the intention-to-treat analysis of all randomised women (except those who had a miscarriage), which gave a similar result. We do agree about the shortcomings of the information included in the ISRCTN registration (www.controlled-trials.com/ISRCTN140 30412/), submitted by onemember of the study team. For example, variables that were eventually listed in the outcomes section include predictor variables such as biochemical measurements during pregnancy. It should also be noted that the planned number of participants stated on the ISRCTN website, of 1000 women, refers to the women to be screened by Doppler ultrasound, and not those to be eventually randomised, as Dr Thornton stated in his commentary. In our conclusion we echoed the words of the Cochrane review that ‘further information is required to assess which women are most likely to benefit’, and proposed that emerging biochemical risk markers, possibly in combination with early uterine artery Doppler ultrasound, are promising candidates to identify such women for future trials.&

Prediction of pre-eclampsia and its subtypes in high-risk cohort: hyperglycosylated human chorionic gonadotropin in multivariate models

BackgroundThe proportion of hyperglycosylated human chorionic gonadotropin (hCG-h) to total human chorionic gonadotropin (%hCG-h) during the first trimester is a promising biomarker for prediction of early-onset pre-eclampsia. We wanted to evaluate the performance of clinical risk factors, mean arterial pressure (MAP), %hCG-h, hCGβ, pregnancy-associated plasma protein A (PAPP-A), placental growth factor (PlGF) and mean pulsatility index of the uterine artery (Uta-PI) in the first trimester in predicting pre-eclampsia (PE) and its subtypes early-onset, late-onset, severe and non-severe PE in a high-risk cohort.MethodsWe studied a subcohort of 257 high-risk women in the prospectively collected Prediction and Prevention of Pre-eclampsia and Intrauterine Growth Restriction (PREDO) cohort. Multivariate logistic regression was used to construct the prediction models. The first model included background variables and MAP. Additionally, biomarkers were included in the second model and mean Uta-PI was included in the third model. All variables that improved the model fit were included at each step. The area under the curve (AUC) was determined for all models.ResultsWe found that lower levels of serum PlGF concentration were associated with early-onset PE, whereas lower %hCG-h was associated with the late-onset PE. Serum PlGF was lower and hCGβ higher in severe PE, while %hCG-h and serum PAPP-A were lower in non-severe PE. By using multivariate regression analyses the best prediction for all PE was achieved with the third model: AUC was 0.66, and sensitivity 36% at 90% specificity. Third model also gave the highest prediction accuracy for late-onset, severe and non-severe PE: AUC 0.66 with 32% sensitivity, AUC 0.65, 24% sensitivity and AUC 0.60, 22% sensitivity at 90% specificity, respectively. The best prediction for early-onset PE was achieved using the second model: AUC 0.68 and 20% sensitivity at 90% specificity.ConclusionsAlthough the multivariate models did not meet the requirements to be clinically useful screening tools, our results indicate that the biomarker profile in women with risk factors for PE is different according to the subtype of PE. The heterogeneous nature of PE results in difficulty to find new, clinically useful biomarkers for prediction of PE in early pregnancy in high-risk cohorts.Trial registrationInternational Standard Randomised Controlled Trial number ISRCTN14030412, Date of registration 6/09/2007, retrospectively registered.

Aspirin in the prevention of pre-eclampsia in high-risk women: a randomised placebo-controlled PREDO Trial and a meta-analysis of randomised trials

Objective  To study the effect of aspirin in the prevention of pre‐eclampsia in high‐risk women.

Aspirin in the prevention of pre-eclampsia in high-risk women: a randomised placebo-controlled PREDO Trial and a meta-analysis of randomised trials: PREDO trial - aspirin in the prevention of pre-eclampsia

Objective  To study the effect of aspirin in the prevention of pre‐eclampsia in high‐risk women.

P18. Angiogenic factors for the prediction of early- and late onset preeclampsia in a high risk cohort

late onset preeclampsia in a high risk cohort P.M. Villa, E. Hamalainen, A. Pesonen, K. Raikkonen, P. Taipale, E. Kajantie, H. Laivuori (Graduate School in Pediatrics and Gynecology, University of Helsinki, Finland, Department of Gynecology and Obstetrics, Helsinki University Central Hospital, Finland, Haartman Institute, University of Helsinki, Finland, HUSLAB, Helsinki University Central Hospital, Finland, Department of Psychology, University of Helsinki, Finland, Iisalmi Hospital, National Institute for Health and Welfare, Helsinki, Finland)