Society for Maternal-Fetal Medicine; Publications Committee. Electronic address: pubs@smfm.org. Society for Maternal-Fetal Medicine Statement: Antihypertensive therapy for mild chronic hypertension in pregnancy-The Chronic Hypertension and Pregnancy trial

Update on Preeclampsia and Hypertensive Disorders of Pregnancy

There have been recent advances in the prevention, diagnosis, and management of hypertensive disorders of pregnancy which complicate approximately 16% of pregnancies in the United States. Initiation of low-dose aspirin by 16 weeks' gestation reduces preeclampsia in high-risk women. The Food and Drug Administration approved the use of the soluble fms-like tyrosine kinase 1/placental growth factor ratio for the short-term prediction of preeclampsia. Pregnancy outcomes are improved in women with chronic hypertension when antihypertensives are initiated at a threshold blood pressure of 140/90 mm Hg. Women with prior preeclampsia have increased cardiovascular disease risk and should receive risk reduction counseling.

Pregnancy Outcomes in Women Who Developed Elevated Blood Pressure and Stage I Hypertension after 20 Weeks Gestation

OBJECTIVE

 The American College of Obstetrics threshold for hypertension (≥140/90 mm Hg) differs from those of the American College of Cardiology (ACC) and the American Heart Association (AHA). It is unknown if ACC/AHA hypertension levels are associated with adverse pregnancy outcomes (APOs) after 20 weeks gestation. The purpose of this study is to analyze APOs in women with blood pressure (BP) in the elevated or stage 1 range after 20 weeks gestation.

STUDY DESIGN

 This was a secondary analysis of the nuMoM2b prospective cohort study of 10,038 nulliparous, singleton pregnancies between 2010 and 2014. BP was measured at three visits during the pregnancy using a standard protocol. Women without medical comorbidities, with normal BP by ACC/AHA guidelines (systolic BP [SBP] < 120 and diastolic BP [DBP] < 80 mm Hg) up to 22 weeks, were included. Exposure was BP between 22 and 29 weeks gestation: normal (SBP < 120 and DBP < 80 mm Hg), elevated (SBP: 120-129 and DBP < 80 mm Hg), and stage 1 (SBP: 130-139 or DBP: 80-89 mm Hg). The primary outcome was hypertensive disorder of pregnancy (HDP) at delivery. Secondary outcomes included fetal growth restriction (FGR), placental abruption, preterm delivery, and cesarean delivery. Multivariable-adjusted odds ratio (aORs) and 95% confidence intervals (CIs) were estimated using logistic regression models.

RESULTS

 Of 4,460 patients that met inclusion criteria, 3,832 (85.9%) had BP in the normal range, 408 (9.1%) in elevated, and 220 (4.9%) in stage 1 range between 22 and 29 weeks. The likelihood of HDP was significantly higher in women with elevated BP (aOR 1.71, 95%CI: 1.18,2.48), and stage 1 BP (aOR: 2.79, 95%CI: 1.84,4.23) compared to normal BP (p < 0.001). Stage 1 BP had twice odds of FGR (aOR: 2.33, 95%CI: 1.22,4.47) and elevated BP had three times odds of placental abruption (aOR: 3.03; 95%CI: 1.24,7.39).

CONCLUSION

 Elevated or stage 1 BP >20 weeks of pregnancy are associated with HDP, FGR, and placental abruption.

KEY POINTS

· Elevated and stage 1 BP increases risk for HDP.. · Elevated BP increases risk for placental abruption.. · Stage 1 BP increases risk for FGR..

Case report of a rare cause of secondary hypertension illustrating the importance of cardio-obstetric preconception counselling

Background

Cardiovascular diseases represent a leading cause of maternal morbidity and mortality in industrialized countries. High blood pressure during pregnancy is a major driver of short- and long-term cardiovascular health in both mother and child. Screening and adequate treatment of elevated blood pressure before pregnancy significantly reduce mortality risk to mother and child.

Case summary

A 30-year-old woman with middle aortic coarctation (MAC) previously treated with aortic stenting was referred to our cardio-obstetrics with plans to become pregnant. The clinical examination revealed severe hypertension with a significant blood pressure gradient between the upper and lower limbs. The patient underwent computed tomography angiography showing re-stenosis of the aorta. After the analysis of the benefit risk of all treatment options, percutaneous transluminal aortic in-stent re-stenting was performed. Following the intervention, blood pressure profile significantly improved but remained slightly elevated further necessitating the introduction of an antihypertensive therapy.

Discussion

This clinical case condenses several challenges encountered in the management of hypertension in women who plan to become pregnant. Firstly, it emphasizes the fact that secondary causes of chronic hypertension, including MAC, do not have to be overlooked in childbearing age patient. Secondly, it illustrates the need for a multidisciplinary analysis of all available treatment options in view of a future pregnancy. Finally, it discusses the particular follow-up and potential complications in pregnant women with MAC and aortic stent.

Postpartum subarachnoid hemorrhage - questions on gestational hypertension diagnosis and treatment threshold: A case report

Hypertensive disorders of pregnancy (HDP) are a leading cause of morbidity and mortality for pregnant patients, but how aggressively to address non-severe hypertension in pregnancy remains controversial. The American College of Obstetrics and Gynecology (ACOG) currently recommends a blood pressure treatment threshold of 140/90 mmHg during pregnancy. However, 2017 American College of Cardiology/American Heart Association (ACC-AHA) guidelines define stage 1 hypertension by blood pressures of >130/80 mmHg within the general population. There is now an understudied population of pregnant patients considered to have stage 1 hypertension by ACC-AHA guidelines but who do not meet the treatment threshold by ACOG's standards. This article presents a patient who met ACC-AHA-defined stage 1 hypertension throughout her pregnancy and went on to develop severe hypertension and a postpartum subarachnoid hemorrhage (SAH) secondary to venous hemorrhage. She presented to the emergency department 17 days postpartum complaining of an extreme headache and with a blood pressure of 230/125 mmHg. Magnetic resonance imaging showed SAH in the parietal region adjacent to the superior sagittal sinus. Magnesium and labetalol were administered followed by a clevidipine drip. The patient was continued on antihypertensives and made a full recovery. This article's objective is to draw attention to the urgent need for increased clarity of practice guidelines, consensus between societies, and further study of peripartum health outcomes for pregnant patients defined as having stage 1 hypertension by 2017 ACC-AHA criteria.

Emerging concepts since the Chronic Hypertension and Pregnancy trial

The recent publication of the Chronic Hypertension and Pregnancy (CHAP) trial has already changed the management of pregnant people with mild chronic hypertension. However, similar to any new intervention or change in management, we have encountered confusion regarding the management and implementation of the "Treatment for mild chronic hypertension during pregnancy" trial findings. In this clinical opinion, we addressed the aspects relating to the implementation that cannot be gleaned from the manuscript but were part of the trial conduct. Furthermore, we discussed several clinical questions that may affect the management of a patient with chronic hypertension following the "Treatment for mild chronic hypertension during pregnancy" trial and provided suggestions based on our experience and opinion.

Care plan for individuals at risk for preeclampsia: shared approach to education, strategies for prevention, surveillance, and follow-up

Preeclampsia is a multisystemic disorder of pregnancy that affects 250,000 pregnant individuals in the United States and approximately 10 million worldwide per annum. Preeclampsia is associated with substantial immediate morbidity and mortality but also long-term morbidity for both mother and offspring. It is now clearly established that a low dose of aspirin given daily, beginning early in pregnancy modestly reduces the occurrence of preeclampsia. Low-dose aspirin seems safe, but because there is a paucity of information about long-term effects on the infant, it is not recommended for all pregnant individuals. Thus, several expert groups have identified clinical factors that indicate sufficient risk to recommend low-dose aspirin preventive therapy. These risk factors may be complemented by biochemical and/or biophysical tests that either indicate increased probability of preeclampsia in individuals with clinical risk factors, or more importantly, identify increased likelihood in those without other evident risk. In addition, the opportunity exists to provide this population with additional care that may prevent or mitigate the short- and long-term effects of preeclampsia. Patient and provider education, increased surveillance, behavioral modification, and other approaches to improve outcomes in these individuals can improve the chance of a healthy outcome. We assembled a group with diverse, relevant expertise (clinicians, investigators, advocates, and public and private stakeholders) to develop a care plan in which providers and pregnant individuals at risk can work together to reduce the risk of preeclampsia and associated morbidities. The plan is for care of individuals at moderate to high risk for developing preeclampsia, sufficient to receive low-dose aspirin therapy, as identified by clinical and/or laboratory findings. The recommendations are presented using the GRADE methodology with the quality of evidence upon which each is based. In addition, printable appendices with concise summaries of the care plan's recommendations for patients and healthcare providers are provided. We believe that this shared approach to care will facilitate prevention of preeclampsia and its attendant short- and long-term morbidity in patients identified as at risk for development of this disorder.

Prediction of Pregnancy-Associated Hypertension Using a Scoring System: A Multicenter Cohort Study

This study aimed to develop an early pregnancy risk scoring model for pregnancy-associated hypertension (PAH) based on maternal pre-pregnancy characteristics, such as mean arterial pressure (MAP), pregnancy-associated plasma protein-A (PAPP-A) or neither. The perinatal databases of seven hospitals from January 2009 to December 2020 were randomly divided into a training set and a test set at a ratio of 70:30. The data of a total pregnant restricted population (women not taking aspirin during pregnancy) were analyzed separately. Three models (model 1, pre-pregnancy factors only; model 2, adding MAP; model 3, adding MAP and PAPP-A) and the American College of Obstetricians and Gynecologists (ACOG) risk factors model were compared. A total of 2840 (8.11%) and 1550 (3.3%) women subsequently developed PAH and preterm PAH, respectively. Performances of models 2 and 3 with areas under the curve (AUC) over 0.82 in both total population and restricted population were superior to those of model 1 (with AUCs of 0.75 and 0.748, respectively) and the ACOG risk model (with AUCs of 0.66 and 0.66) for predicting PAH and preterm PAH. The final scoring system with model 2 for predicting PAH and preterm PAH showed moderate to good performance (AUCs of 0.78 and 0.79, respectively) in the test set. "A risk scoring model for PAH and preterm PAH with pre-pregnancy factors and MAP showed moderate to high performances. Further prospective studies for validating this scoring model with biomarkers and uterine artery Doppler or without them might be required".

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.

Antihypertensives in Pregnancy

Hypertensive disorders of pregnancy (HDP) can result in significant maternal morbidity and even mortality. Available data suggest that many antihypertensives can be safely used in pregnant patients, albeit with close supervision of parameters like fetal growth and amniotic fluid volume. This article summarizes current guidelines on the diagnosis and treatment of hypertension in pregnancy and provides an in-depth guide to the available safety and efficacy data for antihypertensives during pregnancy and postpartum.