Lower systolic blood pressure levels in early pregnancy are associated with a decreased risk of early-onset superimposed preeclampsia in women with chronic hypertension: a multicenter retrospective study

Chronic hypertension diagnosed before or during pregnancy and its effects on pregnancy outcomes

Chronic hypertension (CH) during pregnancy, identified before or within the first 20 weeks, presents varying risks depending on the timing of diagnosis. This real-world study was conducted from January 2018 to June 2023 and included singleton pregnancies with CH to compare pre-pregnancy CH (Group 1) and newly diagnosed CH (Group 2). There were 565 women in the final analysis, with 307 in Group 1 with pre-pregnancy CH and 258 in Group 2 with new-onset CH. Those in Group 1 more frequently had pre-gestational diabetes and a history of hypertensive disorders in pregnancy, whereas Group 2 had a higher incidence of excessive gestational weight gain. Notably, 56.2% of Group 2 patients did not receive antihypertensive treatment before 20 weeks, while the proportion was 36.2% in Group 1, resulting in a significant difference in baseline blood pressure. The study revealed higher incidences of preterm preeclampsia (44.2% vs. 34.9%) and placental abruption (5.4% vs. 2.0%) in Group 2 compared to Group 1. After adjustment, logistic regression indicated that Group 2 had a 1.8-fold higher risk of preterm preeclampsia than Group 1. These findings suggest that pregnant women newly diagnosed with CH in the first 20 weeks face increased adverse outcomes compared to those diagnosed before pregnancy. Intense monitoring and earlier intervention may help manage women with new-onset CH.

Does Developing Interpregnancy Hypertension Affect the Recurrence Risk of Preeclampsia? A Population-Based Cohort Study

BACKGROUND

Preeclampsia in a first pregnancy is a strong risk factor for preeclampsia in a second pregnancy. Whether chronic hypertension developed after a first pregnancy (interpregnancy hypertension) affects the recurrence risk of preeclampsia is unknown.

METHODS

This is a population-based cohort study of 391,645 women with their first and second singleton births between 2006 and 2017. Exposure groups were women with preeclampsia in their first pregnancy, interpregnancy hypertension, or both risk factors. Women with neither risk factor were used as a reference group. We calculated the adjusted relative risk (aRR) with 95% confidence intervals (CIs) for overall preeclampsia in the second pregnancy as well as preterm (<37 gestational weeks) and term (≥37 gestational weeks) subgroups of the disease.

RESULTS

Women with preeclampsia in their first pregnancy who did or did not develop interpregnancy hypertension had rates of preeclampsia in their second pregnancy of 21.5% and 13.6%, respectively. In the same population, the corresponding rates of preterm preeclampsia were 5.5% and 2.6%, respectively. After adjusting for maternal factors, women with preeclampsia in their first pregnancy who developed interpregnancy hypertension and those who did not have almost the same risk of overall preeclampsia in their second pregnancy (aRRs with 95% CIs: 14.51; 11.77-17.89 and 12.83; 12.09-13.62, respectively). However, preeclampsia in the first pregnancy and interpregnancy hypertension had a synergistic interaction on the outcome of preterm preeclampsia (aRR with 95% CI 26.66; 17.44-40.80).

CONCLUSIONS

Women with previous preeclampsia who developed interpregnancy hypertension had a very high rate of preterm preeclampsia in a second pregnancy, and the two risk factors had a synergistic interaction.

2023 update and perspectives

Total 276 manuscripts were published in Hypertension Research in 2022. Here our editorial members picked up the excellent papers, summarized the current topics from the published papers and discussed future perspectives in the sixteen fields. We hope you enjoy our special feature, 2023 update and perspectives in Hypertension Research.

Uncontrolled and masked uncontrolled blood pressure in treated pregnant women with chronic hypertension and risk for preeclampsia/eclampsia

To analyze the relationship between the level of BP achieved with treatment and the risk for development of preeclampsia/eclampsia (PE), we conducted a historical cohort study on 149 consecutive pregnant women with treated chronic hypertension, evaluated between January 1, 2016, and November 31, 2022. According to office BP readings and ambulatory blood pressure monitoring (ABPM) performed after 20 weeks of gestation, the cohort was classified in controlled hypertension, white-coat uncontrolled hypertension, masked uncontrolled hypertension and sustained hypertension. Risks for the development of PE were estimated using logistic regression. One hundred and twenty-four pregnant women with a control BP evaluation were included in this analysis. The rates of PE were 19.4%, 27.3%, 44.8% and 47.1% for controlled, white-coat uncontrolled, masked uncontrolled and sustained uncontrolled hypertension, respectively. Compared with women with controlled hypertension, the relative risk for PE increased markedly in women with sustained uncontrolled (OR 3.69, 95% CI, 1.19-11.45) and masked uncontrolled (OR 3.38, 95% CI, 1.30-11.45) hypertension, but not in those with white-coat uncontrolled (OR 1.56 95% CI, 0.36-6.70); adjustment for covariates did not modify the results. Each mmHg higher of systolic and diastolic daytime ABPM increased the relative risk for PE ~4% and ~5%, respectively. Each mmHg higher of systolic and diastolic nocturnal BP increased the risk ~5% and ~6%, respectively. When these risks were adjusted for ABPM values in opposite periods of the day, only nocturnal ABPM remained as a significant predictor. In conclusion, masked uncontrolled hypertension implies a substantial risk for the development of PE, comparable to those of sustained uncontrolled. The presence of nocturnal hypertension seems important.

Maternal hypertensive traits and adverse outcome in pregnancy: a Mendelian randomization study

INTRODUCTION

Hypertensive disorders of pregnancy are associated with adverse feto-maternal outcomes. Existing evidence is mostly limited to observational studies, which are liable to confounding and bias. This study investigated the causal relevance of component hypertensive indices on multiple adverse pregnancy outcomes using Mendelian randomization.

METHODS

Uncorrelated ( r2  < 0.001) genome-wide significant ( P  < 5 × 10 -8 ) single-nucleotide polymorphisms associated with SBP, DBP and pulse pressure (PP) were selected as instrumental variables. Genetic association estimates for outcomes of preeclampsia or eclampsia, preterm birth, placental abruption and hemorrhage in early pregnancy were extracted from summary statistics of genome-wide association studies in the FinnGen cohort. Two-sample, inverse-variance weighted Mendelian randomization formed the primary analysis method. Odds ratios (OR) are presented per-10 mmHg higher genetically predicted hypertensive index.

RESULTS

Higher genetically predicted SBP were associated with higher odds of preeclampsia or eclampsia [OR 1.81, 95% confidence interval (CI) 1.68-1.96, P  = 5.45 × 10 -49 ], preterm birth (OR 1.09, 95% CI 1.03-1.16, P  = 0.005) and placental abruption (OR 1.33, 95% CI 1.05-1.68, P  = 0.016). Higher genetically-predicted DBP was associated with preeclampsia or eclampsia (OR 2.54, 95% CI 2.21-2.92, P  = 5.35 × 10 -40 ). Higher genetically predicted PP was associated with preeclampsia or eclampsia (OR 1.68, 95% CI 1.47-1.92, P  = 1.9 × 10 -14 ) and preterm birth (OR 1.18, 95% CI 1.06-1.30, P  = 0.002).

CONCLUSION

This study provides genetic evidence to support causal associations of SBP, DBP and PP on multiple adverse outcomes of pregnancy. SBP and PP were associated with the broadest range of adverse outcomes, suggesting that optimized management of blood pressure, particularly SBP, is a key priority to improve feto-maternal health.

Preeclampsia up to date-What's going on?

Preeclampsia is a hypertensive disorder in pregnancy characterized by placental malperfusion and subsequent multi-organ injury. It accounts for approximately 14% of maternal deaths and 10-25% of perinatal deaths globally. In addition, preeclampsia has been attracting attentions for its association with risks for developing chronic diseases in later life for both mother and child. This mini-review discusses on latest knowledge on prediction, prevention, management, and long-term outcomes of preeclampsia and also touches on association between COVID-19 and preeclampsia. HTN hypertension, HDP hypertensive disorders of pregnancy, PE preeclampsia, BP blood pressure, cfDNA cell-free DNA, ST2 human suppression of tumorigenesis 2, sFlt-1 soluble fms-like tyrosine kinase-1, PIGF placental growth factor, VEGF vascular endothelial growth factor, VEGFR VEGF receptor, TGFβ transforming growth factor β, ENG endoglin, sENG soluble ENG, PRES posterior reversible encephalopathy syndrome, AKI acute kidney injury, CVD cardiovascular disease, ESKD end-stage kidney disease, ACE angiotensinogen converting enzyme, Ang angiotensin.

Ambulatory Blood Pressure Monitoring for Diagnosis and Management of Hypertension in Pregnant Women

Hypertension disorders during pregnancy has a wide range of severities, from a mild clinical condition to a life-threatening one. Currently, office BP is still the main method for the diagnosis of hypertension during pregnancy. Despite of the limitation these measurements, in clinical practice office BP of 140/90 mmHg cut point is used to simplify diagnosis and treatment decisions. The out-of-office BP evaluations are it comes to discarding white-coat hypertension with little utility in practice to rule out masked hypertension and nocturnal hypertension. In this revision, we analyzed the current evidence of the role of ABPM in diagnosing and managing pregnant women. ABPM has a defined role in the evaluation of BP levels in pregnant women, being appropriate performing an ABPM to classification of HDP before 20 weeks of gestation and second ABMP performed between 20-30 weeks of gestation to detected of women with a high risk of development of PE. Furthermore, we propose to, discarding white-coat hypertension and detecting masked chronic hypertension in pregnant women with office BP > 125/75 mmHg. Finally, in women who had PE, a third ABPM in the post-partum period could identify those with higher long-term cardiovascular risk related with masked hypertension.

Management of blood pressure in pregnancy: new perspectives from the CHAP trial

PURPOSE OF REVIEW

Chronic hypertension affects up to 10% of pregnancies in the United States and the incidence of hypertensive diseases of pregnancy has more than doubled in the past decade, affecting minority women at disproportionate rates. Recent data show potential benefit by lowering the threshold of blood pressure treatment for pregnant women to >140/90 mmHg.

RECENT FINDINGS

In April 2022, the results of the Chronic Hypertension and Pregnancy (CHAP) trial was published and demonstrated that lower thresholds (>140/90 vs. >160/110 mmHg) for the initiation of antihypertensive therapy during pregnancy resulted in better pregnancy outcomes without negative impacts to foetal growth. In addition, professional societies, such as the American College of Obstetrics and Gynecology (ACOG) and the Society of Maternal Fetal Medicine (SMFM), have released statements supporting the initiation of antihypertensive therapy at elevations above 140/90 mmHg for pregnant women with chronic hypertension based upon these recent reports.

SUMMARY

Treatment of hypertension in pregnant women is controversial, but recent data are emerging that treatment at lower blood pressure thresholds may be associated with improved perinatal outcomes without an increased risk of poor foetal growth. Although these recommendations may be applied to women with chronic hypertension, more research is needed to determine how these guidelines should be applied to other hypertensive diseases of pregnancy.

Update on Hypertension Research in 2021

In 2021, 217 excellent manuscripts were published in Hypertension Research. Editorial teams greatly appreciate the authors' contribution to hypertension research progress. Here, our editorial members have summarized twelve topics from published work and discussed current topics in depth. We hope you enjoy our special feature, "Update on Hypertension Research in 2021".

Hypertensive disorders of pregnancy: definition, management, and out-of-office blood pressure measurement

Hypertensive disorders of pregnancy increase the risk of adverse maternal and fetal outcomes. In 2018, the Japanese classification of hypertensive disorders of pregnancy was standardized with those of other countries, and a hypertensive disorder of pregnancy was considered to be present if hypertension existed during pregnancy and up to 12 weeks after delivery. Strategies for the prevention of hypertensive disorders of pregnancy have become much clearer, but further research is needed on appropriate subjects and methods of administration, and these have not been clarified in Japan. Although guidelines for the use of antihypertensive drugs are also being studied and standardized with those of other countries, the use of calcium antagonists before 20 weeks of gestation is still contraindicated in Japan because of the safety concerns that were raised regarding possible fetal anomalies associated with their use at the time of their market launch. Chronic hypertension is now included in the definition of hypertensive disorders of pregnancy, and blood pressure measurement is a fundamental component of the diagnosis of hypertensive disorders of pregnancy. Out-of-office blood pressure measurements, including ambulatory and home blood pressure measurements, are important for pregnant and nonpregnant women. Although conditions such as white-coat hypertension and masked hypertension have been reported, determining their occurrence in pregnancy is complicated by the gestational week. This narrative review focused on recent reports on hypertensive disorders of pregnancy, including those related to blood pressure measurement and classification.