First-Trimester Risk Factors for Preeclampsia Development in Women Initiating Aspirin by 16 Weeks of Gestation

Clinical and sonographic risk factors for developing pre-eclampsia refractory to aspirin prophylaxis

OBJECTIVE

Identify risk factors for development of preeclampsia refractory to aspirin prophylaxis in women at high-risk of preeclampsia.

MATERIAL AND METHODS

A retrospective cohort study analyzed 206 women identified as high-risk for preeclampsia through first-trimester screening and prescribed aspirin prophylaxis. We compared maternal characteristics, medical history, biochemical markers, and uterine artery Doppler indices between those with and without preeclampsia.

RESULTS

Women with preeclampsia had significantly higher rates of chronic hypertension (54.3% vs. 8.2%), higher first-trimester mean arterial pressure (MAP, 109.6 vs. 95.4 mmHg), and higher body mass index (BMI, 27.6 vs. 24.9) compared to controls. Second-trimester MAP and mean uterine artery pulsatility index (UtA-PI) were also significantly elevated in the preeclampsia group (103.3 mmHg and 1.39, respectively) compared to controls (89.7 mmHg and 1.05). ROC curve analysis identified an optimal second trimester UtA-PI cut-off of 1.36 for predicting preeclampsia, with sensitivity of 49% and specificity of 87.1%. When using a cut-off value of 0.77 for the second-to-first trimester UtA-PI ratio, the sensitivity and specificity were 60% and 90.6%, respectively.

CONCLUSION

Chronic hypertension, high first and second trimester MAP, higher BMI, and elevated second trimester UtA-PI are associated with preeclampsia despite aspirin prophylaxis. Evaluating second trimester UtA-PI or the ratio of second to first trimester UtA-PI may be a promising tool for identifying women who do not respond to aspirin.

Hypertensive Disorders of Pregnancy and the Cardiovascular System: Causes, Consequences, Therapy, and Prevention

Hypertensive disorders of pregnancy continue to be significant contributors to adverse perinatal outcome and maternal mortality, as well as inducing life-long cardiovascular health impacts that are proportional to the severity and frequency of pregnancy complications. The placenta is the interface between the mother and fetus and its failure to undergo vascular maturation in tandem with maternal cardiovascular adaptation by the end of the first trimester predisposes to hypertensive disorders and fetal growth restriction. While primary failure of trophoblastic invasion with incomplete maternal spiral artery remodeling has been considered central to the pathogenesis of preeclampsia, cardiovascular risk factors associated with abnormal first trimester maternal blood pressure and cardiovascular adaptation produce identical placental pathology leading to hypertensive pregnancy disorders. Outside pregnancy blood pressure treatment thresholds are identified with the goal to prevent immediate risks from severe hypertension >160/100 mm Hg and long-term health impacts that arise from elevated blood pressures as low as 120/80 mm Hg. Until recently, the trend for less aggressive blood pressure management during pregnancy was driven by fear of inducing placental malperfusion without a clear clinical benefit. However, placental perfusion is not dependent on maternal perfusion pressure during the first trimester and risk-appropriate blood pressure normalization may provide the opportunity to protect from the placental maldevelopment that predisposes to hypertensive disorders of pregnancy. Recent randomized trials set the stage for more aggressive risk-appropriate blood pressure management that may offer a greater potential for prevention for hypertensive disorders of pregnancy. KEY POINTS: · Optimal management of maternal blood pressure to prevent preeclampsia and its risks is undefined.. · Early gestational rheological damage to the intervillous space predisposes to preeclampsia and FGR.. · First trimester blood pressure management may need to aim for normotension to prevent preeclampsia..

The Role of Acetylsalicylic Acid in the Prevention of Pre-Eclampsia, Fetal Growth Restriction, and Preterm Birth

BACKGROUND

Recent studies suggest that low-dose acetylsalicylic acid (ASA) can lower pregnancy-associated morbidity.

METHODS

This review is based on pertinent publications that were retrieved by a selective search in PubMed, with special attention to systematic reviews, metaanalyses, and randomized controlled trials.

RESULTS

Current meta-analyses document a reduction of the risk of the occurrence of pre-eclampsia (RR 0.85, NNT 50), as well as beneficial effects on the rates of preterm birth (RR 0.80, NNT 37), fetal growth restriction (RR 0.82, NNT 77), and perinatal death (RR 0.79, NNT 167). Moreover, there is evidence that ASA raises the rate of live births after a prior spontaneous abortion, while also lowering the rate of spontaneous preterm births (RR 0.89, NNT 67). The prerequisites for therapeutic success are an adequate ASA dose, early initiation of ASA, and the identification of women at risk of pregnancy-associated morbidity. Side effects of treatment with ASA in this patient group are rare and mainly involve bleeding in connection with the pregnancy (RR 0.87, NNH 200).

CONCLUSION

ASA use during pregnancy has benefits beyond reducing the risk of pre-eclampsia. The indications for taking ASA during pregnancy may be extended at some point in the future; at present, in view of the available evidence, it is still restricted to high-risk pregnancies.

Comparison of the Effect of Nifedipine Alone and the Combination of Nifedipine and Sildenafil in Delaying Preterm Labor: A Randomized Clinical Trial

Objective: Recently, sildenafil as a drug effective in relaxing smooth muscles can be used as an adjunct to delay the onset of uterine contractions and therefore the occurrence of preterm labor. The aim of this study was to evaluate the effect of nifedipine combination with sildenafil on preterm delivery compared with nifedipine alone. Materials and methods: This randomized double-blinded clinical trial was performed on pregnant women with a gestational age of 26-34 weeks with singleton pregnancy and symptoms of preterm delivery. The mothers were randomly assigned into two groups receiving nifedipine plus sildenafil or those receiving nifedipine alone. The time of delivery, maternal and neonatal complications were compared between the two groups. Results: Mothers who received the combination therapy experienced significantly lower preterm delivery within 72 hours of intervention compared to nifedipine alone (4.5% versus 27.3%, p = 0.002). The rate of delivery during the first 7 days after discharge was 7.6% and 31.8% in nifedipine plus sildenafil and nifedipine alone, respectively (P = 0.001). The prevalence of neonatal respiratory distress syndrome (RDS) as well as mean birth weight was higher in the nifedipine group alone. Treatment protocol with nifedipine and sildenafil compared with nifedipine alone was associated with a significant increase in preterm delivery delay (beta =-5.819, p = 0.001). Conclusion: The use of sildenafil in addition to nifedipine causes more delay in delivery in cases of preterm labor, followed by lower risk for RDS, reduces neonatal intensive care unit (NICU) admission, and preserves neonatal birth weight.

ASPRE trial: risk factors for development of preterm pre-eclampsia despite aspirin prophylaxis

OBJECTIVE

To examine the possible risk factors amongst maternal characteristics, medical and obstetric history, pre-eclampsia (PE)-specific biomarkers and estimated-risk group, according to The Fetal Medicine Foundation (FMF) algorithm, that are associated with the development of preterm PE with delivery at < 37 weeks' gestation despite aspirin prophylaxis.

METHODS

This was a secondary analysis of data from the ASPRE trial. The study population consisted of women with singleton pregnancy who were deemed to be at high risk for preterm PE, based on the FMF algorithm that combines maternal factors, mean arterial pressure, uterine artery pulsatility index, serum pregnancy-associated plasma protein-A and placental growth factor (PlGF) at 11-13 weeks' gestation. High-risk women were randomized to receive aspirin (150 mg/day) vs placebo from 11-14 until 36 weeks' gestation. The primary outcome was PE with delivery at < 37 weeks' gestation (preterm PE). Multivariate logistic regression analysis was performed to identify independent predictors of preterm PE after adjusting for the use of aspirin and other covariates.

RESULTS

Among 1592 high-risk women, the incidence of preterm PE was 3.0% (n = 48). The interaction between aspirin usage and history of chronic hypertension was significant in the prediction of preterm PE (P = 0.042), which indicated that there was no treatment effect in high-risk women who had chronic hypertension compared with those who did not. Adjusting for aspirin use, the interaction between aspirin and chronic hypertension and other covariates, independent predictors for the development of preterm PE were PlGF multiples of the median (MoM) (adjusted odds ratio (aOR), 0.226 (95% CI, 0.070-0.723)) and estimated-risk group based on the FMF algorithm. Compared to women with an estimated risk of 1 in 51 to 1 in 100, those with an estimated risk of 1 in 2 to 1 in 10 had a 7-fold higher risk of developing preterm PE (aOR, 6.706 (95% CI, 2.381-18.883)), and those with an estimated risk of 1 in 11 to 1 in 50 had a 3-fold higher risk of preterm PE (aOR, 2.769 (95% CI, 1.105-6.939)). PlGF MoM was an independent predictor for preterm PE among women with an estimated risk of 1 in 2 to 1 in 10 (aOR, 0.055 (95% CI, 0.005-0.668)). Among women with an estimated risk of 1 in 11 to 1 in 100, the use of aspirin was an independent predictor of preterm PE (aOR, 0.276 (95% CI, 0.111-0.689)). The cut-off for PlGF with the best performance for the prediction of preterm PE was 0.712 MoM, with an aOR of 3.677 (95% CI, 1.526-8.862).

CONCLUSION

In pregnancies at high risk of preterm PE identified by screening at 11-13 weeks' gestation using the FMF algorithm, a very high-risk result (estimated risk ≥ 1 in 50), compared to an estimated risk of 1 in 51 to 1 in 100, chronic hypertension, compared to no chronic hypertension, and low PlGF concentration (< 0.712 MoM), compared to PlGF ≥ 0.712 MoM, were associated with the development of preterm PE despite aspirin prophylaxis. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Impact of Chronic Hypertension and Antihypertensive Treatment on Adverse Perinatal Outcomes: Systematic Review and Meta-Analysis

Background Maternal chronic hypertension is associated with adverse pregnancy outcomes. Previous studies examined the association between either chronic hypertension or antihypertensive treatment and adverse pregnancy outcomes. We aimed to synthesize the evidence on the effect of chronic hypertension/antihypertensive treatment on adverse pregnancy outcomes. Methods and Results Medline/PubMed, EMBASE, and Web of Science were searched; we included observational studies and assessed the effect of race/ethnicity, where possible, following a registered protocol (CRD42019120088). Random-effects meta-analyses were used. A total of 81 studies were identified on chronic hypertension, and a total of 16 studies were identified on antihypertensive treatment. Chronic hypertension was associated with higher odds of preeclampsia (adjusted odd ratio [aOR], 5.43; 95% CI, 3.85-7.65); cesarean section (aOR, 1.87; 95% CI, 1.6-2.16); maternal mortality (aOR, 4.80; 95% CI, 3.04-7.58); preterm birth (aOR, 2.23; 95% CI, 1.96-2.53); stillbirth (aOR, 2.32; 95% CI, 2.22-2.42); and small for gestational age (SGA) (aOR, 1.96; 95% CI, 1.6-2.40). Subgroup analyses indicated that maternal race/ethnicity does not influence the observed associations. Women with chronic hypertension on antihypertensive treatment (versus untreated) had higher odds of SGA (aOR, 1.86; 95% CI, 1.38-2.50). Conclusions Chronic hypertension is associated with adverse pregnancy outcomes, and these associations appear to be independent of maternal race/ethnicity. In women with chronic hypertension, those on treatment had a higher risk of SGA, although the number of studies was limited. This could result from a direct effect of the treatment or because severe hypertension during pregnancy is a risk factor for SGA and women with severe hypertension are more likely to be treated. The effect of antihypertensive treatment on SGA needs to be further tested with large randomized controlled trials.

Recognizing Cardiovascular Risk After Preeclampsia: The P4 Study

Background

There is increased risk of hypertension, early cardiovascular disease, and premature mortality in women who have had preeclampsia. This study was undertaken to determine the upper limit of normal blood pressure (BP) 6 months postpartum and the frequency of women with prior preeclampsia who had BP above these limits, as part of the P4 (Post‐Partum Physiology, Psychology and Pediatric) follow‐up study.

Methods and Results

BP was measured by sphygmomanometer, 24‐hour ambulatory BP monitoring, and non‐invasive central BP at 6 months postpartum in 302 women who had normotensive pregnancy and 90 who had preeclampsia. The upper limit of normal BP (mean+2 SD) for women with normotensive pregnancy was 122/79 mm Hg for routine BP, 115/81 mm Hg for central BP, and 121/78 mm Hg for 24‐hour ambulatory BP monitoring. Traditional normal values detected only 3% of women who had preeclampsia as having high BP 6 months postpartum whereas these new values detected between 13% and 19%. Women with preeclampsia had greater body mass index (27.8 versus 25.0, P<0.001) and left ventricular wall thickness but similar augmentation index. They also had lower high‐density lipoprotein (59±15 versus 65±16 mg/dL, P=0.002), higher triglycerides (77±51 versus 61±35 mg/dL, P=0.005), and higher homeostatic model assessment score (2.1±1.8 versus 1.3±1.9, P<0.001).

Conclusions

Clinicians wishing to detect high BP in these women should be aware of the lower than usual upper limit of normal for this young cohort and where possible should use 24‐hour ambulatory BP monitoring to detect these changes. This may define a subgroup of women who had preeclampsia for whom targeted BP lowering therapy would be successful.

Registration

URL: https://anzctr.org.au/Trial/Registration/TrialReview.aspx?id=365295&isReview=true; Unique identifier: ACTRN12613001260718.

Molecular Targets of Aspirin and Prevention of Preeclampsia and Their Potential Association with Circulating Extracellular Vesicles during Pregnancy

Uncomplicated healthy pregnancy is the outcome of successful fertilization, implantation of embryos, trophoblast development and adequate placentation. Any deviation in these cascades of events may lead to complicated pregnancies such as preeclampsia (PE). The current incidence of PE is 2–8% in all pregnancies worldwide, leading to high maternal as well as perinatal mortality and morbidity rates. A number of randomized controlled clinical trials observed the association between low dose aspirin (LDA) treatment in early gestational age and significant reduction of early onset of PE in high-risk pregnant women. However, a substantial knowledge gap exists in identifying the particular mechanism of action of aspirin on placental function. It is already established that the placental-derived exosomes (PdE) are present in the maternal circulation from 6 weeks of gestation, and exosomes contain bioactive molecules such as proteins, lipids and RNA that are a “fingerprint” of their originating cells. Interestingly, levels of exosomes are higher in PE compared to normal pregnancies, and changes in the level of PdE during the first trimester may be used to classify women at risk for developing PE. The aim of this review is to discuss the mechanisms of action of LDA on placental and maternal physiological systems including the role of PdE in these phenomena. This review article will contribute to the in-depth understanding of LDA-induced PE prevention.

The effects of sildenafil in maternal and fetal outcomes in pregnancy: A systematic review and meta-analysis

BACKGROUND

The number of studies associating the use of sildenafil in gestation is increasing. This drug inhibits phosphodiesterase type 5 (PDE5), an enzyme responsible for degradation of nitric oxide, and its efficacy is greater in the placental territory, as the maternal side of the placenta have more PDE5 than other sites. For this reason, promising results have been observed related to the prevention of preeclampsia and intrauterine growth restriction and to improvement of maternal-fetal morbidity in cases of placental insufficiency.

OBJECTIVE

To evaluate the benefits of using sildenafil in pregnancy.

SEARCHED STRATEGY

MEDLINE, ClinicalTrials.gov, Embase, LILACS and Cochrane databases were searched through September 2018. There was no restriction in language or year of publication. This study was registered in PROSPERO (CRD42017060288).

SELECTION CRITERIA

Randomized clinical trials which used sildenafil for treatment or prevention of obstetric diseases compared with placebo were selected.

DATA COLLECTION AND ANALYSIS

The results were obtained using the inverse variance method for continuous variables and Man-Whitney for categorical variables.

MAIN RESULTS

Among a population of 598 pregnant women from the seven clinical trials included, 139 had pre-eclampsia, 275 had intrauterine growth restriction, and 184 had oligohydramnios. A significant increase of 222.58 grams [27.75 to 417.41] was observed in the fetal weight at birth of patients taking sildenafil. The other outcomes did not show any statistical significance. This may be due to the small number of patients used in each study and the great heterogeneity between the groups.

CONCLUSIONS

Sildenafil could be associated with increasing fetal weight at birth in placental insufficiency despite the limitations of this meta-analysis, even though more studies in this field are needed to introduce this drug into obstetric clinical practice.

Maternal blood-pressure trends throughout pregnancy and development of pre-eclampsia in women receiving first-trimester aspirin prophylaxis

OBJECTIVES

To study women who initiated aspirin in the first trimester for high risk of pre-eclampsia, and compare blood-pressure trends throughout pregnancy between those with normal outcome and those who subsequently developed pre-eclampsia.

METHODS

Women were enrolled into a prospective observational study at 9-14 weeks' gestation. This was a secondary analysis of those who started daily doses of 81 mg of aspirin before 16 weeks for increased risk of pre-eclampsia based on maternal history and bilateral uterine artery notching. Enrollment characteristics and blood-pressure measurements throughout gestation were compared between women who did and those who did not develop pre-eclampsia.

RESULTS

Of the 237 women who initiated first-trimester aspirin prophylaxis, 29 (12.2%) developed pre-eclampsia. A total of 2881 serial blood-pressure measurements obtained between 4 and 41 weeks' gestation (747 in the first trimester, 1008 in the second and 1126 in the third) showed that women with pre-eclampsia started pregnancy with higher blood pressure and maintained this trend despite taking aspirin (mean arterial blood pressure in women with pre-eclampsia = (0.13 × gestational age (weeks)) + 93.63, vs (0.11 × gestational age (weeks)) + 82.61 in those without; P < 0.005). First-trimester diastolic and second-trimester systolic blood pressure were independent risk factors for pre-eclampsia (β = 1.087 and 1.050, respectively; r²  = 0.24, P < 0.0001). When average first-trimester diastolic blood pressure was >74 mmHg, the odds ratio for pre-eclampsia was 6.5 (95% CI, 2.8-15.1; P < 0.001) and that for pre-eclampsia before 34 weeks was 14.6 (95% CI, 1.72-123.5; P = 0.004). If, in addition, average second-trimester systolic blood pressure was >125 mmHg, the odds ratio for pre-eclampsia was 9.4 (95% CI, 4.1-22.4; P < 0.001) and that for early-onset disease was 34.6 (95% CI, 4.1-296.4; P = 0.004).

CONCLUSION

In women treated with prophylactic aspirin from the first trimester, those who develop pre-eclampsia have significantly and sustained higher blood pressure from the onset of pregnancy compared with those who do not develop pre-eclampsia. This raises the possibility that mildly elevated blood pressure predisposes women to abnormal placentation, which then acts synergistically with elevated blood pressure to predispose such women to pre-eclampsia to a degree that is incompletely mitigated by aspirin. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Maternal hemodynamics in normal pregnancy and in pregnancy affected by pre-eclampsia

OBJECTIVES

To determine if, in a high-risk group of women in the first half of pregnancy, those who develop pre-eclampsia (PE) with fetal growth restriction (FGR) demonstrate distinct hemodynamics compared with those with PE in the absence of FGR (PE only).

METHODS

Cardiac output (CO), peripheral vascular resistance (PVR) and mean arterial pressure (MAP) were measured at the first hospital visit at 9-24 weeks' gestation in 69 women who had chronic hypertension and 67 who had had a hypertensive disorder in a previous pregnancy. These women were divided into five groups according to pregnancy outcome. In total, 19 subsequently developed PE only, 22 developed PE with FGR, 17 developed pregnancy-induced hypertension, 39 had chronic hypertension without PE or FGR and 39 had had a hypertensive disorder in a previous pregnancy without PE, pregnancy-induced hypertension or FGR in the index pregnancy. The hemodynamic values in each of these groups were compared with those in a cohort of 300 low-risk women with normal pregnancy.

RESULTS

In all the high-risk groups, PVR and MAP were higher than in women with a normal pregnancy, but CO was lower in the group of women with PE and FGR, whereas in the other high-risk groups, it was not significantly different from normal.

CONCLUSIONS

In women who develop PE, there is evidence of high PVR and MAP from the first half of pregnancy, whilst PE and FGR are associated with failure in physiological expansion of CO. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Antepartum Care of Women Who Are Obese During Pregnancy: Systematic Review of the Current Evidence

INTRODUCTION

Nearly 40% of US women of childbearing age are obese. Obesity during pregnancy is associated with multiple risks for both the woman and fetus, yet clinicians often feel unprepared to provide optimal antepartum care for this group of women. We collected and reviewed current evidence concerning antepartum care of women who are obese during pregnancy.

METHODS

We conducted a systematic review using PRISMA guidelines. Current evidence relating to the pregnancy care of women with a prepregnancy body mass index of 30kg/m2 or higher was identified using MEDLINE databases via PubMed, Embase, and Web of Science Core Collection between January 2012 and February 2018.

RESULTS

A total of 354 records were located after database searches, of which 63 met inclusion criteria. Topic areas for of included studies were: pregnancy risk and outcomes related to obesity, communication between women and health care providers, gestational weight gain and activity/diet, diabetic disorders, hypertensive disorders, obstructive sleep apnea, mental health, pregnancy imaging and measurement, late antepartum care, and preparation for labor and birth.

DISCUSSION

Midwives and other health care providers can provide better antepartum care to women who are obese during pregnancy by incorporating evidence from the most current clinical investigations.

Prediction and prevention of pre-eclampsia in Asian subpopulation

The benefit of the early administration of aspirin to reduce preterm pre-eclampsia among screened positive European women from multivariate algorithmic approach (ASPRE trial) has opened an intense debate on the feasibility of universal screening. This review aims to assess the new perspectives in the combined screening of pre-eclampsia in the first trimester of pregnancy and the chances for prevention using low-dose aspirin with special emphasis on the particularities of the Asian population. PubMed, CENTRAL and Embase databases were searched from inception until 15 November 2017 using combinations of the search terms: preeclampsia, Asian, prenatal screening, early prediction, ultrasonography, pregnancy, biomarker, mean arterial pressure, soluble fms-like tyrosine kinase-1, placental growth factor, pregnancy-associated plasma protein-A and pulsatility index. This is not a systematic review or meta-analysis, so the risk of bias of the selected published articles and heterogeneity among the studies need to be considered. The prevalence of pre-eclampsia and serum levels of biochemical markers in Asian are different from Caucasian women; hence, Asian ethnicity needs to be corrected for in the algorithmic assessment of multiple variables to improve the screening performance. Aspirin prophylaxis may still be viable in Asian women, but resource implication needs to be considered. Asian ethnicity should be taken into account before implementing pre-eclampsia screening strategies in the region. The variables included can be mixed and matched to achieve an optimal performance that is appropriate for economical restriction in individual countries.

Preterm preeclampsia in relation to country of birth

OBJECTIVE

To examine the association between maternal country of birth and the risk of preeclampsia+preterm birth (PTB).

STUDY DESIGN

We completed a population-based study in the entire province of Ontario, where there is universal access to obstetrical care. We included 881 700 singleton livebirths among Canadian-born mothers and 305 547 births among immigrant mothers. Adjusted risk ratios (aRRs) were adjusted for maternal age, parity and income quintile.

RESULTS

Compared with a rate of preeclampsia+PTB of 4.0 per 1000 among Canadian-born mothers, the aRR of preeclampsia+PTB at 24 to 36 weeks was significantly higher for immigrant women from Nigeria (1.79, 95% confidence interval (CI) 1.12 to 2.84), the Philippines (1.54, 95% CI 1.30 to 1.86), Colombia (1.68, 95% CI 1.04 to 2.73), Jamaica (2.06, 95% CI 1.66 to 2.57) and Ghana (2.12, 95% CI 1.40 to 3.21). The aRRs generally followed a similar pattern for secondary outcomes. Specifically, women from Ghana were at highest risk of preeclampsia+very PTB (4.55, 95% CI 2.57 to 8.06), and women from Jamaica at the highest risk of preeclampsia+indicated PTB (1.89, 95% CI 1.43 to 2.50).

CONCLUSION

The risk of preeclampsia+PTB is highest among women from a select number of countries. This information can enhance initiatives aimed at reducing the risk of PTB related to preeclampsia.

Maternal preeclampsia and risk for cardiovascular disease in offspring

Hypertensive disease of pregnancy (HDP) has been associated with elevated lifetime cardiovascular risk, including stroke, myocardial disease, coronary artery disease, and peripheral arterial disease. These two entities share common risk factors such as obesity, insulin resistance, diabetes, and hypertension. This article will evaluate the current literature on the maternal and fetal cardiovascular risks posed by HDP. The landmark study by Barker et al. demonstrated increased cardiovascular risk in growth-restricted infants, which may also be associated with HDP. Research has demonstrated the effects that HDP may have on the vascular and nephron development in offspring, particularly with respect to endothelial and inflammatory markers. In order to control for confounding variables and better understand the relationship between HDP and lifetime cardiovascular risk, future research will require following blood pressure and metabolic profiles of the parturients and their offspring.

Prediction of preeclampsia utilizing the first trimester screening examination

OBJECTIVE

To derive a prediction rule for preeclampsia and early onset preeclampsia requiring delivery <34 weeks using first trimester maternal, ultrasound, and serum markers.

STUDY DESIGN

Prospective cohort study of women enrolled at first trimester screening. Maternal history, demographics, anthropometry, ultrasound parameters, and serum analytes were compared between women with preeclampsia and normal outcome. The prediction rule was derived by Lasso logistic regression analysis.

RESULTS

In 2441 women, 108 (4.4%) women developed preeclampsia, and 18 (0.7%) early preeclampsia. Nulliparity, prior hypertension, diabetes, prior preeclampsia, mean arterial pressure, and the log pregnancy-associate pregnancy protein-A multiples of the median were primary risk factors. Prediction rules for preeclampsia/early preeclampsia had an area under the curve of 0.82/0.83 respectively. Preeclampsia was predicted with 49% sensitivity and early preeclampsia with 55% sensitivity for a 10% false positive rate.

CONCLUSION

First trimester prediction rules using parameters currently available at first trimester screening identify a significant proportion of women with subsequent preeclampsia.

First-trimester prediction of pre-eclampsia: external validity of algorithms in a prospectively enrolled cohort

OBJECTIVE

To evaluate the performance of published first-trimester prediction algorithms for pre-eclampsia (PE) in a prospectively enrolled cohort of women.

METHOD

A MEDLINE search identified first-trimester screening-prediction algorithms for early-onset (requiring delivery < 34 weeks) and late-onset (requiring delivery ≥ 34 weeks) PE. Maternal variables, ultrasound parameters and biomarkers were determined prospectively in singleton pregnancies enrolled between 9 and 14 weeks. Prediction algorithms were applied to this population to calculate predicted probabilities for PE. The performance of the prediction algorithms was compared with that in the original publication and evaluated for factors explaining differences in prediction.

RESULTS

Six early and two late PE prediction algorithms were applicable to 871-2962 women, depending on the variables required. The prevalence of early PE was 1.0-1.2% and of late PE was 4.1-5.0% in these patient subsets. One early PE prediction algorithm performed better than in the original publication (80% detection rate (DR) of early PE for 10% false-positive rate (FPR)); the remaining five prediction algorithms underperformed (29-53% DR). Prediction algorithms for late PE also underperformed (18-31% DR, 10% FPR). Applying the screening cut-offs based on the highest Youden index probability scores correctly detected 40-80% of women developing early PE and 71-82% who developed late PE. Exclusion of patients on first-trimester aspirin resulted in DRs of 40-83% and 65-82% for early and late PE, respectively.

CONCLUSION

First-trimester prediction algorithms for PE share a high negative predictive value if applied to an external population but underperform in their ability to correctly identify women who develop PE. Further research is required to determine the factors responsible for the suboptimal external validity.

External validity of first-trimester algorithms in the prediction of pre-eclampsia disease severity

OBJECTIVE

To compare disease features in women with pre-eclampsia between those who are correctly identified (true positive) and those who are missed (false negative) when applying first-trimester prediction algorithms for pre-eclampsia to a prospectively enrolled population.

METHOD

Six first-trimester early (requiring delivery < 34 weeks' gestation) pre-eclampsia algorithms were applied to a prospective cohort of singleton pregnancies enrolled at first-trimester screening. Maternal outcomes, neonatal outcomes and severity parameters for pre-eclampsia were compared between true-positive and false-negative predictions.

RESULTS

Twenty of 2446 (0.8%) women developed early pre-eclampsia, with 65% of these developing severe features and 20% HELLP syndrome. At enrollment, true-positive cases were more likely to be African-American and chronically hypertensive, while false-negative cases were more likely to be Caucasian. At delivery, true-positive cases were more likely to have pre-eclampsia superimposed on hypertension, severely elevated blood pressure and creatinine level > 1.1 mg/dL. False-negative cases were more likely to have HELLP syndrome (all P < 0.05).

CONCLUSION

In an urban population with a high prevalence of chronic hypertension, patients who are correctly identified by first-trimester screening models are more likely to develop pre-eclampsia superimposed on chronic hypertension with severely elevated blood pressure and evidence of renal failure. In contrast, patients who are missed by these algorithms are more likely to have HELLP syndrome. Further research is needed to confirm these findings and the algorithm adjustments that may be necessary to better predict pre-eclampsia phenotypes.