"Hypertension in Pregnancy Intervention Trial At Term" and "Disproportionate Intrauterine Growth Intervention Trial At Term" Studies.

In 2003, in the context of a national research funding program in which obstetric research was prioritized, several perinatal centers took the initiative to jointly submit a number of applications to the subsidy programs of Effectiveness Research and Prevention of ZonMw. This has led to the funding of the Obstetric Consortium with several projects, including the "Hypertension in Pregnancy Intervention Trial At Term" and the "Disproportionate Intrauterine Growth Intervention Trial At Term" studies. The studies showed that induction of labor for hypertension and growth restriction at term was the appropriate management. Subsequent implementation improved maternal and perinatal outcomes.

Planned delivery or expectant management in preeclampsia: an individual participant data meta-analysis.

OBJECTIVE: Pregnancy hypertension is a leading cause of maternal and perinatal mortality and morbidity. Between 34+0 and 36+6 weeks gestation, it is uncertain whether planned delivery could reduce maternal complications without serious neonatal consequences. In this individual participant data meta-analysis, we aimed to compare planned delivery to expectant management, focusing specifically on women with preeclampsia. DATA SOURCES: We performed an electronic database search using a prespecified search strategy, including trials published between January 1, 2000 and December 18, 2021. We sought individual participant-level data from all eligible trials. STUDY ELIGIBILITY CRITERIA: We included women with singleton or multifetal pregnancies with preeclampsia from 34 weeks gestation onward. METHODS: The primary maternal outcome was a composite of maternal mortality or morbidity. The primary perinatal outcome was a composite of perinatal mortality or morbidity. We analyzed all the available data for each prespecified outcome on an intention-to-treat basis. For primary individual patient data analyses, we used a 1-stage fixed effects model. RESULTS: We included 1790 participants from 6 trials in our analysis. Planned delivery from 34 weeks gestation onward significantly reduced the risk of maternal morbidity (2.6% vs 4.4%; adjusted risk ratio, 0.59; 95% confidence interval, 0.36-0.98) compared with expectant management. The primary composite perinatal outcome was increased by planned delivery (20.9% vs 17.1%; adjusted risk ratio, 1.22; 95% confidence interval, 1.01-1.47), driven by short-term neonatal respiratory morbidity. However, infants in the expectant management group were more likely to be born small for gestational age (7.8% vs 10.6%; risk ratio, 0.74; 95% confidence interval, 0.55-0.99). CONCLUSION: Planned early delivery in women with late preterm preeclampsia provides clear maternal benefits and may reduce the risk of the infant being born small for gestational age, with a possible increase in short-term neonatal respiratory morbidity. The potential benefits and risks of prolonging a pregnancy complicated by preeclampsia should be discussed with women as part of a shared decision-making process.

Neonatal developmental and behavioral outcomes of immediate delivery versus expectant monitoring in mild hypertensive disorders of pregnancy: 5-year outcomes of the HYPITAT II trial.

OBJECTIVE: To compare effects of immediate delivery vs expectant monitoring on neurodevelopmental and behavioral outcomes at 5 years of age in offspring of women with mild late preterm hypertensive disorders. STUDY DESIGN: We studied children born during the HYPITAT-II trial, in which 704 women with a hypertensive disorder between 34 and 37 weeks of gestation were randomized to immediate delivery or expectant monitoring. Participating women were asked to complete the Ages and Stages Questionnaire (ASQ) for developmental outcome and the Child Behavior Checklist (CBCL) for behavioral problems when their child was 5 years old. Outcomes were dichotomized and analyzed by logistic regression analysis. We also assessed factors influencing development and behavior at both 2 and 5 years after a hypertensive pregnancy. RESULTS: Five years after the original study 322(46%) women were contacted for follow-up, of whom 148 (46%) responded. In the delivery group 22%(n = 14/65) of the children had an abnormal ASQ score compared to 21% (n = 13/62) in the expectant monitoring group (p = 0.9). Abnormal CBCL-scores were found in 19% (n = 14/72) of the children in the delivery group versus in 27% (n = 20/75) in the expectant monitoring group (p = 0.3). The main predictor of development and behavior at 2 and 5 years was fetal growth restriction (for abnormal development OR 2.1, CI 1.0-4.4; for behavior problems OR 2.2, CI 1.1-5.5). Higher maternal education decreased abnormal behavior outcomes (OR 0.5, CI 0.2-0.9) and a similar tendency was observed for developmental problems (OR 0.6, CI 0.3 - 1.1). CONCLUSION: We did not find different developmental and behavior outcomes at 5 years of age between a management policy of immediate delivery and expectant management in preterm hypertensive disorders. The increased risk of developmental delay at 2 years of age after immediate delivery, we found in the 2 year follow up study, did not persist at 5 years of age.

Neonatal developmental and behavioral outcomes of immediate delivery versus expectant monitoring in mild hypertensive disorders of pregnancy: 2-year outcomes of the HYPITAT-II trial.

BACKGROUND: Management of preterm hypertensive disorders remains a clinical dilemma. The maternal benefits of delivery need to be weighed against the adverse neonatal consequences of preterm birth. Long-term consequences of obstetric management in offspring of women with hypertensive disorders in preterm pregnancy are largely unknown. We report child neurodevelopmental and behavioral outcomes at 2 years after the Hypertension and Preeclampsia Intervention Trial at near Term (HYPITAT-II) trial, which compared immediate delivery versus expectant monitoring in mild late preterm hypertensive disorders of pregnancy. OBJECTIVE: To compare effects of immediate delivery vs expectant monitoring on neurodevelopmental and behavioral outcomes at 2 years of age in offspring of women with mild late preterm hypertensive disorders. MATERIALS AND METHODS: We studied children born in the HYPITAT-II trial, a study in which women (n = 704) with hypertensive disorders of pregnancy who were between 34 and 37 weeks' gestation were randomized to immediate delivery or expectant monitoring. Participating women were asked to complete the Ages and Stages Questionnaire for developmental outcome and the Child Behavior Checklist for behavioral problems when their toddlers were 2 years old. RESULTS: We approached 545 of 704 randomized women (77%); 330 of 545 (61%) returned the questionnaires. In the immediate delivery group, 45 of 162 infants (28%) had an abnormal Ages and Stages Questionnaire score compared to 27 of 148 (18%) in the expectant monitoring group (risk difference, 9.6%; 95% CI, 0.3-18.0%); P = .045. In the pregnancies (n = 94) that delivered before reaching 36 weeks, 27% (n = 25) had an abnormal Ages and Stages Questionnaire score compared to 22% (n = 47) when delivered after 36 weeks (odds ratio, 0.77; confidence interval, 0.44-1.34). An abnormal Child Behavior Checklist outcome was found in 31 of 175 (18%) in the delivery group vs 24 of 166 (15%) in the expectant monitoring group (risk difference, 3.2%; 95% CI, -4.6% to 11.0%). After correction for maternal education, management strategy remained an independent predictor of abnormal Ages and Stages Questionnaire score (odds ratio, 0.48; confidence interval, 0.24 to -0.96, P = .03). In multivariable analyses, low birth weight, low maternal education, and immediate delivery policy were all significantly associated with an abnormal Ages and Stages Questionnaire score. CONCLUSION: In this study, we found that early delivery in women with late preterm hypertensive disorders is associated with poorer neurodevelopmental outcomes in their children at 2 years of age. These findings indicate an increased risk of developmental delay after early delivery compared to expectant monitoring. This follow-up study underlines the conclusion of the original HYPITAT-II study that, until the clinical situation deteriorates, expectant monitoring remains the most appropriate management strategy in the light of short- and long-term neonatal outcomes in women with preterm hypertensive disorders.

Evaluation of biomarkers for treatment selection using individual participant data from multiple clinical trials.

Biomarkers that predict treatment effects may be used to guide treatment decisions, thus improving patient outcomes. A meta-analysis of individual participant data (IPD) is potentially more powerful than a single-study data analysis in evaluating markers for treatment selection. Our study was motivated by the IPD that were collected from 2 randomized controlled trials of hypertension and preeclampsia among pregnant women to evaluate the effect of labor induction over expectant management of the pregnancy in preventing progression to severe maternal disease. The existing literature on statistical methods for biomarker evaluation in IPD meta-analysis have evaluated a marker's performance in terms of its ability to predict risk of disease outcome, which do not directly apply to the treatment selection problem. In this study, we propose a statistical framework for evaluating a marker for treatment selection given IPD from a small number of individual clinical trials. We derive marker-based treatment rules by minimizing the average expected outcome across studies. The application of the proposed methods to the IPD from 2 studies in women with hypertension in pregnancy is presented.

Prediction of progression to severe disease in women with late preterm hypertensive disorders of pregnancy.

INTRODUCTION: If hypertensive disorders of pregnancy are diagnosed before term, the benefits of immediate delivery need to be weighed against the neonatal consequences of preterm delivery. If we are able to predict which women are at high risk of progression to severe disease, they could be targeted for delivery and maternal complications might be reduced. In addition, this may prevent unnecessary preterm births in women at low risk. MATERIAL AND METHODS: We developed a prediction model using data from the HYPITAT-II trail, which evaluated immediate delivery vs. expectant monitoring in women with non-severe hypertensive disorders of pregnancy between 34 and 37 weeks of gestation. Univariate and multivariate logistic regression analysis were used to identify relevant variables from clinical and laboratory parameters. The performance of the resulting prediction model was assessed by receiver operating characteristic analysis, calibration and bootstrapping, using the average predicted probabilities. RESULTS: We included 519 women, 115 (22.2%) of whom developed severe hypertensive disorders of pregnancy. The prediction model included: maternal age (odds ratio 0.92 per year), gestational age (odds ratio 0.87 per week), systolic blood pressure (odds ratio 1.05 per mmHg), the presence of chronic hypertension (odds ratio 2.4), platelet count (odds ratio 0.996), creatinine (odds ratio 1.02) and lactate dehydrogenase (odds ratio 1.003). The model showed good fit (p = 0.64), fair discrimination (area under the curve 0.76, 95% confidence interval 0.73-0.81, p < 0.001) and could stratify women in three risk groups of average, intermediate and high risk (predicted probabilities <0.22, <0.44 and >0.45, respectively). CONCLUSION: In women with non-severe hypertension in pregnancy near term, progression to severe disease can be predicted. This model requires external validation before it can be applied in practice.

Maternal and neonatal outcomes of pregnancy in women with chronic hypertension: a retrospective analysis of a national register.

INTRODUCTION: Pregnancies complicated by chronic hypertension are at increased risk of adverse pregnancy outcomes. To assess whether planned early delivery might prevent some of these adverse outcomes, we studied maternal and neonatal outcomes of pregnancy in women with chronic hypertension, including gestational-age-specific outcomes. MATERIAL AND METHODS: We performed a retrospective, population-based cohort study, using data from the Netherlands Perinatal Register. We included women with chronic hypertension and normotensive controls who delivered a singleton without congenital anomalies in 2002-2007. We calculated crude and adjusted odds ratios (OR) with 95% CI, compared delivery and ongoing pregnancy using moving averages, and used multiple Cox regression to adjust for differences in baseline characteristics and to examine adverse neonatal outcomes across subgroups of hypertensive disorder. Main outcome measures were composite adverse maternal and neonatal outcomes. RESULTS: We included 3457 (0.3%) women with chronic hypertension and 984 932 normotensive controls. Women with chronic hypertension had adverse maternal outcomes more often (28.7% vs. 6.6%, adjusted OR 5.7, 95% CI 5.3-6.2). Their offspring had an increased rate of neonatal morbidity (17.4% vs. 13.2%, adjusted OR 1.2, 95% CI 1.1-1.4) but not of severe adverse neonatal outcomes (2.5% vs. 2.2%, adjusted OR 0.8, 95% CI 0.6-1.0). The increased risk of adverse maternal outcomes for ongoing pregnancy remained stable around 17% at term. The risk of severe adverse neonatal outcomes for birth was at its lowest between 38 and 40 weeks, mainly in women with iatrogenic onset of delivery. CONCLUSIONS: Women with chronic hypertension are at increased risk of adverse maternal and neonatal outcomes compared with controls throughout pregnancy, including at term. Our results suggest that the optimal timing of delivery might be between 38 and 40 weeks of gestation, but prospective randomized studies should confirm this.

Relevance of individual participant data meta-analysis for studies in obstetrics: delivery versus expectant monitoring for hypertensive disorders of pregnancy.

Like many other research subjects in obstetrics, research on immediate delivery versus expectant monitoring for women with hypertensive disorders of pregnancy faces certain challenges when it comes to interpretation and generalisation of the results; relatively rare outcomes are studied, in a clinically heterogeneous population, while the clinical practice in some countries has dictated that studies in term pregnancy were completed before earlier gestational ages could be studied. This has resulted in multiple smaller studies, some studying surrogate outcome measures, with different in- and exclusion criteria, and without enough power for reliable subgroup analyses. All this complicates the generation of definitive answers and implementation of the results into clinical practice. Performing multiple studies and subsequently pooling their results in a meta-analysis can be a way to overcome the difficulties of studying relatively rare outcomes and subgroups with enough power, as well as a solution to reach a final answer on questions involving an uncertain and possibly harmful intervention. However, in the case of the current studies on delivery versus expectant monitoring in women with hypertensive disorders of pregnancy, differences regarding eligibility criteria, outcome measures and subgroup definitions make it difficult to pool their results in an aggregate meta-analysis. Individual patient data meta-analysis (IPDMA) has the potential to overcome these challenges, because it allows for flexibility regarding the choice of endpoints and standardisation of inclusion and exclusion criteria across studies. In addition, it has more statistical power for informative subgroup analyses. We therefore propose an IPDMA on immediate delivery versus expectant monitoring for hypertensive disorders of pregnancy, and advocate the use of IPDMA for research questions in obstetrics that face similar challenges.

Immediate delivery versus expectant monitoring for hypertensive disorders of pregnancy between 34 and 37 weeks of gestation (HYPITAT-II): an open-label, randomised controlled trial.

BACKGROUND: There is little evidence to guide the management of women with hypertensive disorders in late preterm pregnancy. We investigated the effect of immediate delivery versus expectant monitoring on maternal and neonatal outcomes in such women. METHODS: We did an open-label, randomised controlled trial, in seven academic hospitals and 44 non-academic hospitals in the Netherlands. Women with non-severe hypertensive disorders of pregnancy between 34 and 37 weeks of gestation were randomly allocated to either induction of labour or caesarean section within 24 h (immediate delivery) or a strategy aimed at prolonging pregnancy until 37 weeks of gestation (expectant monitoring). The primary outcomes were a composite of adverse maternal outcomes (thromboembolic disease, pulmonary oedema, eclampsia, HELLP syndrome, placental abruption, or maternal death), and neonatal respiratory distress syndrome, both analysed by intention-to-treat. This study is registered with the Netherlands Trial Register (NTR1792). FINDINGS: Between March 1, 2009, and Feb 21, 2013, 897 women were invited to participate, of whom 703 were enrolled and randomly assigned to immediate delivery (n=352) or expectant monitoring (n=351). The composite adverse maternal outcome occurred in four (1·1%) of 352 women allocated to immediate delivery versus 11 (3·1%) of 351 women allocated to expectant monitoring (relative risk [RR] 0·36, 95% CI 0·12-1·11; p=0·069). Respiratory distress syndrome was diagnosed in 20 (5·7%) of 352 neonates in the immediate delivery group versus six (1·7%) of 351 neonates in the expectant monitoring group (RR 3·3, 95% CI 1·4-8·2; p=0·005). No maternal or perinatal deaths occurred. INTERPRETATION: For women with non-severe hypertensive disorders at 34-37 weeks of gestation, immediate delivery might reduce the already small risk of adverse maternal outcomes. However, it significantly increases the risk of neonatal respiratory distress syndrome, therefore, routine immediate delivery does not seem justified and a strategy of expectant monitoring until the clinical situation deteriorates can be considered. FUNDING: ZonMw.

Adjuvanted vaccines in pregnancy: no evidence for effect of the adjuvanted H1N1/09 vaccination on occurrence of preeclampsia or intra-uterine growth restriction.

OBJECTIVE: During the H1N1/09 pandemic, pregnant women in the Netherlands were vaccinated with an adjuvanted vaccine. During pregnancy, the maternal immune system changes to enable placental development and growth and acceptance of the semi-allogeneic fetus. As an adjuvant is a pro-inflammatory substance, it may interfere with these immunological changes, resulting in poor placentation or placental growth, which may result in preeclampsia (PE) and fetal intra-uterine growth restriction (IUGR). This study investigated a possible association between adjuvanted H1N1/09 vaccination and the development of PE and/or IUGR. STUDY DESIGN: Case-control study. Cases were Dutch women with PE and/or IUGR occurring during H1N1/09 vaccination program. Controls had uncomplicated pregnancies during the same period. Maternal characteristics, pregnancy and neonatal outcomes were collected from medical files. Participants were contacted by telephone to enquire about vaccination. Data were analyzed using t-tests, Chi-square tests or Fisher's exact tests. Multivariate analysis was conducted to control for confounders. RESULTS: We included 254 cases and 247 controls. Of the cases, 90 (35.4%) were vaccinated, compared to 87 (35.2%) of the controls (OR:1.009, 95% CI:0.70-1.46, p:0.961). The majority (73.5%) had been vaccinated in second and third trimester. In multivariate analysis, there were no confounders influencing these results. Exploratory subgroup analysis did not show an association between vaccination status in subgroups of women with either PE or IUGR. CONCLUSION: Our study showed no association between adjuvanted H1N1/09 vaccination and PE and/or IUGR.

Induction of labour versus expectant monitoring for gestational hypertension or mild pre-eclampsia between 34 and 37 weeks' gestation (HYPITAT-II): a multicentre, open-label randomised controlled trial.

BACKGROUND: Gestational hypertension (GH) and pre-eclampsia (PE) can result in severe complications such as eclampsia, placental abruption, syndrome of Hemolysis, Elevated Liver enzymes and Low Platelets (HELLP) and ultimately even neonatal or maternal death. We recently showed that in women with GH or mild PE at term induction of labour reduces both high risk situations for mothers as well as the caesarean section rate. In view of this knowledge, one can raise the question whether women with severe hypertension, pre-eclampsia or deterioration chronic hypertension between 34 and 37 weeks of gestation should be delivered or monitored expectantly. Induction of labour might prevent maternal complications. However, induction of labour in late pre-term pregnancy might increase neonatal morbidity and mortality compared with delivery at term. METHODS/DESIGN: Pregnant women with severe gestational hypertension, mild pre-eclampsia or deteriorating chronic hypertension at a gestational age between 34+0 and 36+6 weeks will be asked to participate in a multi-centre randomised controlled trial. Women will be randomised to either induction of labour or expectant monitoring. In the expectant monitoring arm, women will be induced only when the maternal or fetal condition detoriates or at 37+0 weeks of gestation. The primary outcome measure is a composite endpoint of maternal mortality, severe maternal complications (eclampsia, HELLP syndrome, pulmonary oedema and thromboembolic disease) and progression to severe pre-eclampsia. Secondary outcomes measures are respiratory distress syndrome (RDS), neonatal morbidity and mortality, caesarean section and vaginal instrumental delivery rates, maternal quality of life and costs. Analysis will be intention to treat. The power calculation is based on an expectant reduction of the maternal composite endpoint from 5% to 1% for an expected increase in neonatal RDS from 1% at 37 weeks to 10% at 34 weeks. This implies that 680 women have to be randomised. DISCUSSION: This trial will provide insight as to whether in women with hypertensive disorders late pre-term, induction of labour is an effective treatment to prevent severe maternal complications without compromising the neonatal morbidity. TRIAL REGISTRATION: NTR1792 CLINICAL TRIAL REGISTRATION: http://www.trialregister.nl.