Determinants of neonatal blood pressure

An Update on Pharmacologic Management of Neonatal Hypotension: When, Why, and Which Medication

Anti-hypotensive treatment, which includes dopamine, dobutamine, epinephrine, norepinephrine, milrinone, vasopressin, terlipressin, levosimendan, and glucocorticoids, is a long-established intervention in neonates with arterial hypotension (AH). However, there are still gaps in knowledge and issues that need clarification. The main questions and challenges that neonatologists face relate to the reference ranges of arterial blood pressure in presumably healthy neonates in relation to gestational and postnatal age; the arterial blood pressure level that potentially affects perfusion of critical organs; the incorporation of targeted echocardiography and near-infrared spectroscopy for assessing heart function and cerebral perfusion in clinical practice; the indication, timing, and choice of medication for each individual patient; the limited randomized clinical trials in neonates with sometimes conflicting results; and the sparse data regarding the potential effect of early hypotension or anti-hypotensive medications on long-term neurodevelopment. In this review, after a short review of AH definitions used in neonates and existing data on pathophysiology of AH, we discuss currently available data on pharmacokinetic and hemodynamic effects, as well as the effectiveness and safety of anti-hypotensive medications in neonates. In addition, data on the comparisons between anti-hypotensive medications and current suggestions for the main indications of each medication are discussed.

Blood pressure normative values in preterm infants during postnatal transition

BACKGROUND

The normative blood pressure values in preterm infants still not well defined during postnatal transition. We aimed to create normative blood pressure (BP) reference values in preterm infants <29 weeks gestational age recorded hourly during the postnatal transition.

METHODS

We included only data from hemodynamically stable newborns. Only BP values measured by umbilical arterial catheter (UAC) were included. The regression model showed that only gestational age and postnatal age in hours determine the BP.

RESULTS

We included 206 out of 547 admitted preterm infants. The BP increases with increasing gestational ages and overtime during the postnatal transition. We constructed 5 BP centile values for each gestational group. BP histograms show that the BP most of the time fluctuated between the 5th and 75th centile values, particularity during day one of life.

CONCLUSIONS

The BP trend values gradually increase in stable preterm infants during the postnatal transition, and preterm infants who do not follow this trend might require hemodynamics assessment.

IMPACT

The normative blood pressure is increasing gradually during the first 3 days after birth and is different with gestational ages. This is first normative blood pressure centile values in stable preterm infant and based on invasive blood pressure monitoring. The data enable more accurate monitoring of hemodynamics in preterm infants during postnatal transition.

Common Clinical Scenarios of Systemic Hypertension in the NICU

Hypertension affects ∼1% to 3% of newborns in the NICU. However, the identification and management of hypertension can be challenging because of the lack of data-driven diagnostic criteria and management guidelines. In this review, we summarize the most recent approaches to diagnosis, evaluation, and treatment of hypertension in neonates and infants. We also identify common clinical conditions in neonates in whom hypertension occurs, such as renal vascular and parenchymal disease, bronchopulmonary dysplasia, and cardiac conditions, and address specific considerations for the evaluation and treatment of hypertension in those conditions. Finally, we discuss the importance of ongoing monitoring and long-term follow-up of infants diagnosed with hypertension.

Caring for the hypertensive newborn: a prospective evaluation of risk factors, clinical profile, management, and predictors of outcome of neonatal hypertension

With the advancement of neonatal care and routine blood pressure monitoring, neonatal hypertension (NHT) has been increasingly recognised over the past few decades. NHT is known to cause target organ damage and risk of renal dysfunction later in life. However, diagnosis and management of NHT remain challenging, and there is a lack of evidence on the persistence of hypertension beyond the neonatal period and factors predicting its severity. This study aimed to identify risk factors, clinical profiles, predictors of the severity of hypertension, and short-term outcomes of NHT. A cohort of neonates diagnosed with hypertension requiring pharmacotherapy from September 2019 to July 2021 was prospectively enrolled. Demographic data, risk factors, the severity of hypertension, target organ damage, and follow-up for the persistence of hypertension at 3, 6, and 12 months of age were recorded. Of 1682 neonates admitted during this period, 34 had hypertension requiring pharmacotherapy, with a hospital incidence rate of 2%. Of these, 19 (55.9%) were preterm, 14 (41.2%) very low birth weight, and 15 (44.1%) were small for gestational age. Malignant hypertension was seen in 29 (85%) cases, moderate hypertension in 5 (15%) cases, and target organ damage (heart, brain, liver) was seen in 10 (29.4%) cases. On univariate and multivariate regression, an increasing total number of postnatal risk factors was an independent predictor of the occurrence of hypertensive crisis (OR = 3.5, p = 0.04; 95% CI 1.06-11.42). A significant positive correlation (p = 0.004) was observed between total number of postnatal risk factors and the duration of hospital stay. Renal causes of hypertension were identified significantly earlier (day 14 vs. 23, p = 0.01, 95% CI 2.5-17) and had shorter hospital stay (24 vs 45 days, p = 0.002, 95% CI 834). At 3 months follow-up, 7 (20.6%) babies were still requiring antihypertensive therapy, and 1 (3%) required antihypertensives at 6 and 12 months of age.  Conclusion: NHT is a clinically important but underrecognised entity. Hypertension was seen in preterm, low birth weight neonates and associated with certain maternal and postnatal risk factors, with majority responding to a single drug. Neonates with multiple comorbid illnesses need careful monitoring for hypertension as they are at a higher risk of developing hypertensive crisis. Most NHT cases were normotensive at the time of discharge and did not require pharmacotherapy beyond the neonatal period. What is Known: • Neonatal hypertension (NHT) is an under-recognised entity, and the spectrum of clinical presentation varies from asymptomatic to severe target organ damage. • Hypertension is commonly seen in preterm, low birth weight neonates and associated with certain maternal and postnatal risk factor. What is New: • NHT is mostly transient, but intrauterine growth retardation, use of antenatal steroids, renal dysfunction due to congenital anomalies, drugs, and chronic lung disease may lead to the persistence of hypertension beyond the neonatal period. • Neonates with multiple comorbid illnesses need careful monitoring for hypertension as they are at a higher risk of developing hypertensive crisis. Three-fourths of hypertensive neonates respond to a single antihypertensive drug, and only one-fourth of patients required an additional drug to control hypertension. Most neonates respond to short duration of treatment, and only a few patients require long-term therapy.

Trajectory of Systemic Blood Pressure in Early Life: A Cohort Study

Objective. To track the BP (blood pressure) trajectory of healthy infants during the first year of life of healthy infants born in Northeast Brazil. Methods. In this cohort study, BP was assessed by oscillometry at the first 24 hours of life and 12 months of age. Results. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) increased with age (P < .001) and were not influenced by gender (SBP: P = .178 and DBP: P = .623) or type of delivery (SBP: P = .827 and DBP: P = .106), when compared between the first 24 hours of life and 12 months of age. Conclusion. The data from the present study increased knowledge about the trajectory of BP during the first year of life. The increase in BP between the first month and the first year of life was not influenced by gender or type of delivery.

Strong Association between Inotrope Administration and Intraventricular Hemorrhage, Gestational Age, and the Use of Fentanyl in Very Low Gestational Age Infants: A Retrospective Study

This was a single center, retrospective cohort study designed to evaluate the association between the administration of inotropes to hypotensive very low gestational age infants (VLGAI) and prenatal and neonatal risk factors. Inpatient medical records were reviewed to identify neonates treated with inotropes (treated group) and a control group for comparison. Two hundred and twenty two (222) VLGAI (less than 32 weeks' gestation) were included in the final analysis and were stratified based on timing of treatment with 83 infants (37.4%) and 139 infants (62.6%) in the treated and control groups, respectively. A total of 56/83 (67%) received inotropes for arterial hypotension during the first 3 days (early treatment subgroup) and 27/83 (32.5%) after 3 days of life (late-treated subgroup). Fentanyl, severe intraventricular hemorrhage (IVH), and gestational age (GA) were the risk factors most significantly associated with the need for inotrope use both during the first 3 days of life and the whole NICU stay, before and after adjustment for confounders. In conclusion, fentanyl, severe IVH, and GA are the risk factors most strongly associated with the need for inotrope treatment in VLGAI. Measures to modify these risk factors may decrease the need for cardiovascular medications and improve outcomes.

Neonatal systemic hypertension across the PHIS database: An update

BACKGROUND

The definition of systemic hypertension in the neonatal population remains elusive given the variability of normative blood pressure measurements. Inadequate literature exists about incidence, therapy and long-term management of systemic hypertension in neonates. We aimed to describe the current incidence of neonatal systemic hypertension, differences in demographic and risk factors data.

METHODS

Retrospective cohort of neonates (≤28 days) admitted to a neonatal intensive care unit participating in Pediatric Health Information System (PHIS) between Jan 2010 and December 2020 with an ICD 9/10 code for hypertension. Patients were excluded if they had congenital heart disease lesions that might contribute to systemic hypertension or had incomplete data.

RESULTS

There were a total of 2494 hypertensive patients among the 432,367 NICU patients meeting the study inclusion criteria, with an incidence of 0.6%. Patients with hypertension were significantly more likely to die before discharge compared to patients without HTN (8.4% versus 3.8%, respectively, p < 0.001). Of the 2494, 52.8% received at least one antihypertensive agent, with hydralazine being the most prescribed agent (29.7%).

CONCLUSION

Diagnosis of Systemic hypertension continues to increase in the neonatal population, despite absence of well-defined criteria necessitating targeted medical management. A consensus guideline which addresses this very important condition is beneficial.

Phthalates cause a low-renin phenotype commonly found in premature infants with idiopathic neonatal hypertension

Since the 1970s, when the initial reports of neonatal hypertension related to renal artery thromboembolism were published, other secondary causes of neonatal hypertension have been reported. Those infants with no identifiable cause of hypertension were labeled with a variety of terms. Herein, we describe such infants as having idiopathic neonatal hypertension (INH). Most, but not all, of these hypertensive infants were noted to have bronchopulmonary dysplasia (BPD). More recently, reports described common clinical characteristics seen in INH patients, whether or not they had BPD. This phenotype includes low plasma renin activity, presentation near 40 weeks postmenstrual age, and a favorable response to treatment with spironolactone. A small prospective study in INH patents showed evidence of mineralocorticoid receptor activation due to inhibition of 11β-HSD2, the enzyme that converts cortisol to the less potent mineralocorticoid-cortisone. Meanwhile, phthalate metabolites have been shown to inhibit 11β-HSD2 in human microsomes. Premature infants can come in contact with exceptionally large phthalate exposures, especially those infants with BPD. This work describes a common low-renin phenotype, commonly seen in patients categorized as having INH. Further, we review the evidence that hypertension in INH patients with the low-renin phenotype may be mediated by phthalate-associated inhibition of 11β-HSD2. Lastly, we review the implications of these findings regarding identification, treatment, and prevention of the low-renin hypertension phenotype seen in premature infants categorized as having INH.

Systemic Hypertension in Infants with Bronchopulmonary Dysplasia

PURPOSE OF REVIEW

Neonatal hypertension is increasingly recognized as improvements in neonatal intensive care have led to increased survival of premature infants. Among infants with bronchopulmonary dysplasia (BPD), the rates of hypertension are much higher than the general neonatal population. However, the etiology and pathophysiology of this increased risk of hypertension in neonates with lung disease remain unclear.

RECENT FINDINGS

Among infants with bronchopulmonary dysplasia, the rates of hypertension are much higher than the general neonatal population. New studies suggest outcomes in neonates with BPD with hypertension are usually good, with resolution of hypertension in most infants with lung disease. Several potential mechanisms of hypertension in this patient population have been recently proposed. This review focuses on the recent epidemiologic data on prevalence of hypertension in neonates with bronchopulmonary dysplasia, reviews the typical clinical course, and discusses available strategies for management of infants with bronchopulmonary dysplasia that develop hypertension.

Neonatal Hypertension

Neonatal hypertension is uncommon but is becoming increasingly recognized. Normative blood pressure data are limited, as is research regarding the risks, treatment, and long-term outcomes. Therefore, there are no clinical practice guidelines and management is based on clinical judgment and expert opinion. Recognition of neonatal hypertension requires proper blood pressure measurement technique. When hypertension is present there should be a thorough clinical, laboratory, and imaging evaluation to promptly diagnose causes needing medical or surgical management. This review provides a practical overview for the practicing clinician regarding the identification, evaluation, and management of neonatal hypertension.

Assessment of the Cardiovascular Risk Profile of Infants Exposed to Pre-eclampsia in-utero: A Prospective Case-Control Study in South African Children of African Ancestry

Background: It has been reported that maternal gestational environment may be programmed to have a significant impact on foetal and offspring health later in life. Studies have shown that children born to pre-eclamptic mothers are prone to obesity, hypertension, and diabetes in their adult life. However, such findings are yet to be established in an African population. This protocol is for a study aiming to investigate the relationship between pre-eclampsia (PE) and cardiovascular risk in children born to pre-eclamptic mothers in a South African population of African descents.

Methods: A prospective case-control design will be employed to recruit pre-eclamptic and normotensive pregnant women and their offspring after birth. Pregnant women will be assessed for cardiovascular risk factors including PE, obesity, haemodynamics, lipids, glycaemic indices, oxidative stress, and vascular function at 30 weeks of gestation. The cardiovascular risk profile of their offspring will be assessed at birth and 6 weeks later. The difference in cardiovascular risk profile between children born to the pre-eclamptic and normotensive mothers will be compared and the correlation between maternal and offspring cardiovascular risks will be investigated.

Discussion: This will be the first prospective study to assess the in-utero effect of cardiovascular risk in offspring born to pre-eclamptic women of African ancestry. It is expected that findings from this study will provide information on the cardiovascular effect of in-utero exposure to PE in a population of African ancestry. This knowledge will advise policy on the management of women with PE with a view of protecting cardiovascular health in offspring.

Antenatal and perinatal factors influencing neonatal blood pressure: a systematic review

OBJECTIVE

A comprehensive understanding of the factors contributing to perinatal blood pressure is vital to ensure optimal postnatal hemodynamic support. The objective of this study was to review existing literature on maternal and perinatal factors influencing blood pressure in neonates up to 3 months corrected age.

METHODS

A systematic search of published literature in OVID Medline, OVID Embase and the COCHRANE library identified publications relating to maternal factors affecting blood pressure of neonates up to corrected age of 3 months. Summary data were extracted and compared (PROSPERO CRD42018092886).

RESULTS

Of the 3683 non-duplicate publications identified, 44 were eligible for inclusion in this review. Topics elicited were sociodemographic factors, maternal health status, medications, smoking during pregnancy, and cord management at birth. Limited data were available for each factor. Results regarding the impact of these factors on neonatal blood pressure were inconsistent across studies.

CONCLUSIONS

There is insufficient evidence to draw definitive conclusions regarding the impact of various maternal and perinatal factors on neonatal blood pressure. Future investigations of neonatal cardiovascular therapies should account for these factors in their study design. Similarly, studies on maternal diseases and perinatal interventions should include neonatal blood pressure as part of their primary or secondary analyses.

Elimination of Intravenous Di-2-Ethylhexyl Phthalate Exposure Abrogates Most Neonatal Hypertension in Premature Infants with Bronchopulmonary Dysplasia

(1) Background: The incidence of hypertension in very low birthweight (VLBW) infants in a single neonatal intensive care unit (NICU) dropped markedly during a 2-year period when the IV fluid (IVF) in both the antenatal unit and the NICU temporarily changed to a di-2-ethylhexyl phthalate (DEHP)-free formulation. The objective of the current report is to document this observation and demonstrate the changes in incidence of hypertension were not associated with the variation in risk factors for hypertension; (2) Methods: The charts of all VLBW infants born in a single NICU during a 7-year span were reviewed. This time includes 32 months of baseline, 20 months of DEHP-free IVF, 20 months of IVF DEHP re-exposure, and two 4-month washout intervals. The group of interest was limited to VLBW infants with bronchopulmonary dysplasia (BPD). Chi-square analysis was used to compare incidence of hypertension among periods. Vermont Oxford NICU Registry data were examined for variation in maternal and neonatal risk factors for hypertension; Results: Incidence of hypertension in VLBW infants with BPD decreased from 7.7% (baseline) to 1.4% when IVF was DEHP-free, rising back to 10.1% when DEHP-containing IVF returned to use. Risk factors for neonatal hypertension were stable across the 3 study periods in the NICU’s group of VLBW infants; (3) Conclusions: Serendipitous removal of IVF containing DEHP resulted in near elimination of hypertension in one NICU—an effect entirely reversed after the same brand of DEHP-containing IVF returned to clinical use. These results suggest that DEHP exposure from IVF plays a major role in neonatal hypertension.

Neonatal blood pressure before and after delayed umbilical cord clamping

OBJECTIVE

To describe values of blood pressure (BP) before and after delayed cord clamping (DCC) in healthy term neonates born to low risk pregnancies, examine differences in the temporal patterns of BP during this transition, and assess potential correlation of these parameters with maternal and perinatal clinical and demographic variables.

METHODS

Prospective observational study of term infants eligible for DCC born vaginally from uncomplicated pregnancies. Neonatal BP was estimated noninvasively before DCC, at 30 min and 24 h of life. Median, minimum, maximum, mean and standard deviation, as well as percentiles for BP values were calculated. Pearson correlation assessed the correlation between demographic and clinical variables and BP measurements. Spearman correlation studied the association between BP parameters prior to DCC and Apgar scores. Repeated measures ANOVA and Tukey post hoc analyses were used to compare BP measurements over time. A p-value of <.05 was considered significant.

RESULTS

A total of 54 patients were included. Mean neonatal birthweight was 3185 g and gestational age 39/3 weeks. The mean values for the systolic, diastolic, and mean BP prior to DCC were 97 ± 24.9 mmHg, 58 ± 21.9 mmHg and 67 ± 27.7 mmHg respectively. A statistically significant difference was detected when comparing BP values obtained before DCC with those measured afterwards (Figure 1). A positive correlation was found between SBP and MAP prior to DCC and Apgar scores at 1 min. [Figure: see text].

CONCLUSION

We describe novel values of BP before DCC in healthy term infants following vaginal delivery. Data suggest that neonates whose cord is clamped in a delayed fashion experience an increase blood pressures immediately after birth, followed by a significant drop within 30 min to levels that remain unchanged at 24 h of life. BP values obtained after DCC in our study are similar to those found by previous authors. Further studies are needed to determine the clinical significance of these findings and assess the potential of BP prior to DCC to evaluate immediate postnatal adaptation.

LIMITATIONS

Results generalizability may have been limited by varying degrees of neonatal resuscitation, inability to perform more than one measurement before cord clamping ensued, as well as an unequal distribution of self-reported race in our cohort. Also, noninvasive BP estimates have proven less accurate that invasive methods. Finally, our cohort was comprised by a relatively small sample and larger studies will be required to corroborate our findings.

The hypertensive neonate

Hypertension in neonates is increasingly recognized because of improvements in neonatal intensive care that have led to improved survival of premature infants. Although normative data on neonatal blood pressure remain limited, several factors appear to be important in determining blood pressure levels in neonates, especially gestational age, birth weight and maternal factors. Incidence is around 1% in most studies and identification depends on careful blood pressure measurement. Common causes of neonatal hypertension include umbilical catheter associated thrombosis, renal parenchymal disease, and chronic lung disease, and can usually be identified with careful diagnostic evaluation. Given limited data on long-term outcomes and use of antihypertensive medications in these infants, clinical expertise may need to be relied upon to decide the best approach to treatment. This review will discuss these concepts and identify evidence gaps that should be addressed.

Intervention and Outcome for Neonatal Hypotension

Many observational studies have shown that infants with blood pressures (BPs) that are in the lower range for their gestational age tend to have increased complications such as an increased rate of significant intraventricular hemorrhage and adverse long-term outcome. This relationship does not prove causation nor should it create an indication for treatment. However, many continue to intervene with medication for low BP on the assumption that an increase in BP will result in improved outcome. Only adequately powered prospective randomized controlled trials can answer the question of whether individual treatments of low BP are beneficial.

Machine Learning to Support Hemodynamic Intervention in the Neonatal Intensive Care Unit

Hemodynamic support in neonatal intensive care is directed at maintaining cardiovascular wellbeing. At present, monitoring of vital signs plays an essential role in augmenting care in a reactive manner. By applying machine learning techniques, a model can be trained to learn patterns in time series data, allowing the detection of adverse outcomes before they become clinically apparent. In this review we provide an overview of the different machine learning techniques that have been used to develop models in hemodynamic care for newborn infants. We focus on their potential benefits, research pitfalls, and challenges related to their implementation in clinical care.

The changing spectrum of hypertension in premature infants

OBJECTIVE

The objective is to document changes in the etiologic spectrum of hypertension in premature infants.

STUDY DESIGN

We reviewed all cases of systemic hypertension (HTN) in premature infants at two centers over 8 years. Infants were sorted into categorical groups as described in 2012 by Flynn. Analyses included frequency of diagnosis, timecourse of HTN, and diagnostics. Phthalate exposure via intravenous fluid and respiratory equipment was compared among groups and centers.

RESULTS

One hundred and twenty-nine infants having 130 episodes of HTN met the inclusion criteria. Sixty-five percent of cases were classified as pulmonary and 16% as miscellaneous. Plasma renin activity (PRA) was undetectable or <11 ng/mL/h in almost all hypertensive infants. Cases categorized as Pulmonary, medications/intoxications, and miscellaneous presented near 40 weeks postmenstrual age, with low PRA and large phthalate exposures.

CONCLUSIONS

High PRA HTN has been replaced by low PRA in most cases, and may be due to phthalate exposure.

Phthalate-associated hypertension in premature infants: a prospective mechanistic cohort study

BACKGROUND

Phthalates are associated with increased blood pressure in children. Large exposures to di-(2-ethylhexyl) phthalate (DEHP) among premature infants have been a cause for concern.

METHODS

We conducted a prospective observational cohort study to determine if DEHP exposures are related to systolic blood pressure (SBP) in premature infants, and if this exposure is associated with activation of the mineralocorticoid receptor (MR). Infants were monitored longitudinally for 8 months from birth. Those who developed idiopathic hypertension were compared with normotensive infants for DEHP exposures. Appearance of urinary metabolites after exposure was documented. Linear regression evaluated the relationship between DEHP exposures and SBP index and whether urinary cortisol/cortisone ratio (a surrogate marker for 11β-HSD2 activity) mediated those relationships. Urinary exosomes were quantified for sodium transporter/channel expression and interrogated against SBP index.

RESULTS

Eighteen patients met the study criteria, nine developed transient idiopathic hypertension at a postmenstrual age of 40.6 ± 3.4 weeks. The presence of urinary DEHP metabolites was associated with prior IV and respiratory tubing DEHP exposures (p < 0.05). Both IV and respiratory DEHP exposures were greater in hypertensive infants (p < 0.05). SBP index was related to DEHP exposure from IV fluid (p = 0.018), but not respiratory DEHP. Urinary cortisol/cortisone ratio was related to IV DEHP and SBP index (p < 0.05). Sodium transporter/channel expression was also related to SBP index (p < 0.05).

CONCLUSIONS

Increased blood pressure and hypertension in premature infants are associated with postnatal DEHP exposure. The mechanism of action appears to be activation of the MR through inhibition of 11β-HSD2.

Neonatal hypertension: an educational review

Hypertension is encountered in up to 3% of neonates and occurs more frequently in neonates requiring hospitalization in the neonatal intensive care unit (NICU) than in neonates in newborn nurseries or outpatient clinics. Former NICU neonates are at higher risk of hypertension secondary to invasive procedures and disease-related comorbidities. Accurate measurement of blood pressure (BP) remains challenging, but new standardized methods result in less measurement error. Multiple factors contribute to the rapidly changing BP of a neonate: gestational age, postmenstrual age (PMA), birth weight, and maternal factors are the most significant contributors. Given the natural evolution of BP as neonates mature, a percentile cutoff of 95% for PMA has been the most common definition used; however, this is not based on outcome data. Common causes of neonatal hypertension are congenital and acquired renal disease, history of umbilical arterial catheter placement, and bronchopulmonary dysplasia. The treatment of neonatal hypertension has mostly been off-label, but as evidence accumulates, the safety of medical management has increased. The prognosis of neonatal hypertension remains largely unknown and thankfully most often resolves unless secondary to renovascular disease, but further research is needed. This review discusses important factors related to neonatal hypertension including BP measurement, determinants of BP, and management of neonatal hypertension.

Neonatal hypertension: cases, causes, and clinical approach

Neonatal hypertension is increasingly recognized as dramatic improvements in neonatal intensive care, advancements in our understanding of neonatal physiology, and implementation of new therapies have led to improved survival of premature infants. A variety of factors appear to be important in determining blood pressure in neonates, including gestational age, birth weight, and postmenstrual age. Normative data on neonatal blood pressure values remain limited. The cause of hypertension in an affected neonate is often identified with careful diagnostic evaluation, with the most common causes being umbilical catheter-associated thrombosis, renal parenchymal disease, and chronic lung disease. Clinical expertise may need to be relied upon to decide the best approach to treatment in such patients, as data on the use of antihypertensive medications in this age group are extremely limited. Available data suggest that long-term outcomes are usually good, with resolution of hypertension in most infants. In this review, we will take a case-based approach to illustrate these concepts and to point out important evidence gaps that need to be addressed so that management of neonatal hypertension may be improved.

Diagnosis, Evaluation, and Management of High Blood Pressure in Children and Adolescents

Systemic hypertension is a major cause of morbidity and mortality in adulthood. High blood pressure (HBP) and repeated measures of HBP, hypertension (HTN), begin in youth. Knowledge of how best to diagnose, manage, and treat systemic HTN in children and adolescents is important for primary and subspecialty care providers.

OBJECTIVES

To provide a technical summary of the methodology used to generate the 2017 "Clinical Practice Guideline for Screening and Management of High Blood Pressure in Children and Adolescents," an update to the 2004 "Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents."

DATA SOURCES

Medline, Cochrane Central Register of Controlled Trials, and Excerpta Medica Database references published between January 2003 and July 2015 followed by an additional search between August 2015 and July 2016.

STUDY SELECTION

English-language observational studies and randomized trials.

METHODS

Key action statements (KASs) and additional recommendations regarding the diagnosis, management, and treatment of HBP in youth were the product of a detailed systematic review of the literature. A content outline establishing the breadth and depth was followed by the generation of 4 patient, intervention, comparison, outcome, time questions. Key questions addressed: (1) diagnosis of systemic HTN, (2) recommended work-up of systemic HTN, (3) optimal blood pressure (BP) goals, and (4) impact of high BP on indirect markers of cardiovascular disease in youth. Once selected, references were subjected to a 2-person review of the abstract and title followed by a separate 2-person full-text review. Full citation information, population data, findings, benefits and harms of the findings, as well as other key reference information were archived. Selected primary references were then used for KAS generation. Level of evidence (LOE) scoring was assigned for each reference and then in aggregate. Appropriate language was used to generate each KAS based on the LOE and the balance of benefit versus harm of the findings. Topics that could not be researched via the stated approach were (1) definition of HTN in youth, and (2) definition of left ventricular hypertrophy. KASs related to these stated topics were generated via expert opinion.

RESULTS

Nearly 15 000 references were identified during an initial literature search. After a deduplication process, 14 382 references were available for title and abstract review, and 1379 underwent full text review. One hundred twenty-four experimental and observational studies published between 2003 and 2016 were selected as primary references for KAS generation, followed by an additional 269 primary references selected between August 2015 and July 2016. The LOE for the majority of references was C. In total, 30 KASs and 27 additional recommendations were generated; 12 were related to the diagnosis of HTN, 13 were related to management and additional diagnostic testing, 3 to treatment goals, and 2 to treatment options. Finally, special additions to the clinical practice guideline included creation of new BP tables based on BP values obtained solely from children with normal weight, creation of a simplified table to enhance screening and recognition of abnormal BP, and a revision of the criteria for diagnosing left ventricular hypertrophy.

CONCLUSIONS

An extensive and detailed systematic approach was used to generate evidence-based guidelines for the diagnosis, management, and treatment of youth with systemic HTN.

Incidence of neonatal hypertension from a large multicenter study [Assessment of Worldwide Acute Kidney Injury Epidemiology in Neonates-AWAKEN]

BACKGROUND

Hypertension occurs in up to 3% of neonates admitted to the Neonatal Intensive Care Unit (NICU), and is a potentially under-recognized condition. The aim of this study was to examine the incidence of documented and undiagnosed hypertension from the 24-center Assessment of Worldwide Acute Kidney Injury Epidemiology in Neonates (AWAKEN) database, and to assess risk factors for hypertension according to gestational age.

METHODS

Diagnosed hypertension was documented if an infant had a discharge diagnosis of hypertension and/or discharged on antihypertensive medications. Undiagnosed hypertension was defined when infants did not have a diagnosis of hypertension, but >50% of the lowest mean, diastolic and systolic blood pressure recordings were >95^th percentile for gestational age.

RESULTS

Of the 2162 neonates enrolled in the study, hypertension was documented in 1.8%. An additional 3.7% were defined as having undiagnosed hypertension. There was a significant correlation with neonatal hypertension and acute kidney injury (AKI). Additional risk factors for neonatal hypertension were hyperbilirubinaemia, Caucasian race, outborn, vaginal delivery, and congenital heart disease. Protective factors were small for gestational age, multiple gestations, and steroids for fetal maturation.

CONCLUSIONS

Neonatal hypertension may be an under-recognized condition. AKI and other risk factors predispose infants to hypertension.

Characteristics of hypertension in premature infants with and without chronic lung disease: a long-term multi-center study

BACKGROUND

Many causes for neonatal hypertension in premature infants have been described; however in some cases no etiology can be attributed. Our objectives are to describe such cases of unexplained hypertension and to compare hypertensive infants with and without chronic lung disease (CLD).

METHODS

We reviewed all cases of hypertension in premature infants referred from 18 hospitals over 16 years. Inclusion criteria were hypertension occurring at <6 months of age and birth at <37 weeks gestation; the main exclusion criterion was known secondary hypertension. Continuous variables were compared using analysis of variance. Nominal variables were compared using chi-square tests.

RESULTS

A total of 97 infants met the inclusion criteria, of whom 37 had CLD. Among these infants, hypertension presented at a mean of 11.3 ± 3.2 chronological weeks of age and a postmenstrual age of 39.6 ± 3.6 weeks. Diagnostic testing was notable for plasma renin activity (PRA) being <11 ng/mL/h in 98% of hypertensive infants. Spironolactone was effective monotherapy in 51 of 56 cases of hypertension. Hypertension resolved in all infants, with an average treatment duration of 25 weeks. Significant differences between the two groups of infants were a 0.4 kg lower birthweight and a 2.5 weeks younger gestational age at birth in those with CLD (p < 0.01, p < 0.01, respectively). Hypertension presented in those with CLD 1.8 weeks later, but at the same postmenstrual age as those without CLD (p < 0.01, p = 0.45, respectively).

CONCLUSION

Premature infants with unexplained hypertension, with and without CLD, presented at a postmenstrual age of 40 weeks with low PRA, transient time course, and a favorable response to spironolactone treatment.

Clinical Practice Guideline for Screening and Management of High Blood Pressure in Children and Adolescents

These pediatric hypertension guidelines are an update to the 2004 "Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents." Significant changes in these guidelines include (1) the replacement of the term "prehypertension" with the term "elevated blood pressure," (2) new normative pediatric blood pressure (BP) tables based on normal-weight children, (3) a simplified screening table for identifying BPs needing further evaluation, (4) a simplified BP classification in adolescents ≥13 years of age that aligns with the forthcoming American Heart Association and American College of Cardiology adult BP guidelines, (5) a more limited recommendation to perform screening BP measurements only at preventive care visits, (6) streamlined recommendations on the initial evaluation and management of abnormal BPs, (7) an expanded role for ambulatory BP monitoring in the diagnosis and management of pediatric hypertension, and (8) revised recommendations on when to perform echocardiography in the evaluation of newly diagnosed hypertensive pediatric patients (generally only before medication initiation), along with a revised definition of left ventricular hypertrophy. These guidelines include 30 Key Action Statements and 27 additional recommendations derived from a comprehensive review of almost 15 000 published articles between January 2004 and July 2016. Each Key Action Statement includes level of evidence, benefit-harm relationship, and strength of recommendation. This clinical practice guideline, endorsed by the American Heart Association, is intended to foster a patient- and family-centered approach to care, reduce unnecessary and costly medical interventions, improve patient diagnoses and outcomes, support implementation, and provide direction for future research.

Applying developmental programming to clinical obstetrics: my ward round

The theory of developmental programming is supported by accumulating evidence, both observational and experimental. The direct application of the principles of developmental programming by clinicians to benefit pregnant women remains an area of limited attention. Examining a selection of inpatients at an obstetric referral center, I searched for situations in which clinical decision making could be driven by the principles of developmental programming. I also looked for situations in which the clinical research agenda could be dictated by these concepts. In the decision to undertake preventive measures to avoid preeclampsia, the offspring’s perspective may support more liberal application of calcium and aspirin. Consideration of the long-term health perspective of the offspring could drive choices in the management of obesity and diabetes in pregnancy. The administration of corticosteroids in women delivering by elective cesarean at term may have modest short-term benefits, but additional trials are necessary to investigate long-term offspring health. The offspring of women suffering hyperemesis gravidarum may benefit from nutritional therapy. The long-term health of the offspring could affect couples’ choice for IVF or expectant management. Applying the principles of developmental programming to the management of pregnant women could drive clinical decision making and is driving the clinical research agenda. Increasingly, developmental programming concepts are becoming an integral part of clinical practice, as well as determining the choice of outcomes in trials in obstetrics and fertility medicine. The presented cases underscore the need for more research to guide clinical practice.

Preeclampsia: effect on newborn blood pressure in the 3 days following preterm birth: a cohort study

Maternal hypertension and preeclampsia are associated with greater risk of hypertension in childhood, and cardiovascular events in adulthood. However, whether preeclampsia affects blood pressure (BP) in the newborn period is unclear. Previous neonatal studies were based on small sample sizes, very low birth weight or gestational age or limited duration (h). To delineate hemodynamic repercussions of maternal preeclampsia on preterm infants (gestational ages ⩾29 weeks) with/without intrauterine growth restriction (IUGR) in the first 3 postnatal days, we conducted a single-centre retrospective cohort study of singleton births at 29-35 weeks of gestation in Montreal, Canada, from 2008 to 2011. Data were obtained from medical charts. Exclusion criteria included congenital anomalies, infections, pre-pregnancy maternal hypertension and gestational diabetes. IUGR was defined as birth weight <10th percentile. Of the 338 eligible neonates, 230 were included: 75 preeclampsia-IUGR, 72 preeclampsia-only and 83 controls. The preeclampsia-IUGR group had longer gestations than the preeclampsia-only or control groups (32.4±1.8 vs. 31.3±1.6 vs. 31.7±1.6 weeks, respectively; P<0.001). Mean BPs increased over the first 3 days for all newborns (P<0.001). Infants with preeclampsia-associated IUGR had the highest systolic and diastolic BPs, even after adjustment for birth weight, and preeclampsia-only the next highest. Systolic BP progression showed significant differences between groups (P<0.05). We conclude that impact of preeclampsia on children blood pressure was manifest within days of birth, over and above coexisting IUGR. Long-term cardiovascular follow-up and targeted preventive strategies are advised for this underrecognized high-risk population.