Risk factors for persistent pulmonary hypertension of the newborn

Risk Factors and Mortality in Newborns with Persistent Pulmonary Hypertension: A Six-Year Single-Center Experience

Objectives

Persistent pulmonary hypertension (PPHT) of the newborn is a disorder of circulatory transition resulting in high pulmonary vascular resistance with extrapulmonary right-to-left shunts causing hypoxemia. In this study, our aim was to evaluate the risk factors, administered treatments, and mortality of patients followed in our neonatal intensive care unit (NICU) due to PPHT over the past six years.

Methods

Patients diagnosed with PPHT and followed in the NICU between January 2017 and November 2022 were included in the study. The sociodemographic characteristics, diagnoses that could lead to pulmonary hypertension, the presence of congenital anomalies, the duration of respiratory support treatment and hospital follow-up, treatments administered for PPHT, and mortality rates were evaluated.

Results

Out of 21 patients diagnosed with persistent pulmonary hypertension, 9 of them (42.9%) were male. The mean gestational age of the patients was 37.6±3.7 weeks, and their birth weight was 3006±819grams. The APGAR scores at 1 and 5 minutes were 4(2-7) and 6(3-8), respectively. Risk factors during the antenatal period included fetal distress (38.1%), oligohydramnios (23.8%), intrauterine growth restriction (23.8%), gestational diabetes (14.3%), preeclampsia (4.8%), and chorioamnionitis (4.8%). The median duration of invasive mechanical ventilation for cases requiring respiratory support was 20.1 days, while the median duration of non-invasive ventilation was 3.7 days. Patients with a diagnosis of persistent pulmonary hypertension were treated with inhaled nitric oxide (iNO) in 76.2% of cases, milrinone in 66.7% of cases, sildenafil in 52.4% of cases, and iloprost in 14.3% of cases. The length of hospital stay for patients was 38.4 days, and 9 (42.9%) patients died. The patients who died had severe PPHT along with fetal inflammatory response syndrome (FIRS), congenital heart disease, pulmonary hypoplasia, pneumothorax, hypoxic-ischemic encephalopathy (HIE), and congenital anomalies.

Conclusion

Persistent pulmonary hypertension, characterized by severe hypoxemia, is a neonatal emergency that necessitates early intervention, effective treatment of the underlying cause to prevent potential short-term and long-term morbidities and mortality. Effective treatment of the underlying cause in patients diagnosed with PPHT could reduce morbidity and mortality. It is inevitable to avoid the loss of patients with major abnormalities, severe comorbidities, and unpreventable organ dysfunctions.

Etiology, Diagnosis and Management of Persistent Pulmonary Hypertension of the Newborn in Resource-limited Settings

Persistent Pulmonary Hypertension of the Newborn (PPHN) is more common in Low and middle income countries (LMICs) due to high incidence of sepsis, perinatal asphyxia and meconium aspiration syndrome. Presence of hypoxic respiratory faillure and greater than 5% difference in preductal and post ductal saturation increases clinical sucipision for PPHN. The availability of Inhaled nitric oxide and extracorporaeal membrane oxygenation is limited but pulmonary vasodilators such as sildenafil are readily available in most LMICs.

Gestational Diabetes Mellitus Impedes Fetal Lung Development Through Exosome-Dependent Crosstalk Between Trophoblasts and Lung Epithelial Cells

Background

Fetal lung underdevelopment (FLUD) is associated with neonatal and childhood severe respiratory diseases, among which gestational diabetes mellitus (GDM) play crucial roles as revealed by recent prevalence studies, yet mechanism underlying GDM-induced FLUD, especially the role of trophoblasts, is not all known.

Methods

From the perspective of trophoblast-derived exosomes, we established in vitro, ex vivo, in vivo and GDM trophoblast models. Utilizing placenta-derived exosomes (NUB-exos and GDMUB-exos) isolated from normal and GDM umbilical cord blood plasma and trophoblast-derived exosomes (NC-exos and HG-exos) isolated from HTR8/SVneo trophoblasts medium with/without high glucose treatment, we examined their effects on fetal lung development and biological functions.

Results

We found that, compared with the NUB-exos group, the exosome concentration increased in GDMUB-exos group, and the content of exosomes also changed evidenced by 61 dysregulated miRNAs. After applying these exosomes to A549 alveolar type II epithelial cells, the proliferation and biological functions were suppressed while the proportion of apoptotic cells was increased as compared to the control. In ex vivo studies, we found that GDMUB-exos showed significant suppression on the growth of the fetal lung explants, where the number of terminal buds and the area of explant surface decreased and shrank. Besides, the expression of Fgf10, Vegfa, Flt-1, Kdr and surfactant proteins A, B, C, and D was downregulated in GDMUB-exos group, whilst Sox9 was upregulated. For in vivo studies, we found significant suppression of fetal lung development in GDMUB-exos group. Importantly, we found consistent alterations when we used NC-exos and HG-exos, suggesting a dominant role of trophoblasts in placenta-derived exosome-induced FLUD.

Conclusion

In conclusion, GDM can adversely affect trophoblasts and alter exosome contents, causing crosstalk disorder between trophoblasts and fetal lung epithelial cells and finally leading to FLUD. Findings of this study will shine insight into the theoretical explanation for the pathogenesis of FLUD.

Echocardiographic Reference Ranges of Non-Invasive Myocardial Work Indices in Newborns

Background: Myocardial work (MCW), estimated using non-invasive pressure-strain loops, is a novel approach for assessing left ventricular function. MCW offers potential advantages over left ventricular ejection fraction and global longitudinal strain (GLS). This study aimed to establish a reference range for MCW in newborns.

Methods and Results: Overall, 113 healthy newborns (mean [±SD] birth weight 3,120±378 g) were included in the study. After entering peripheral systolic and diastolic blood pressure (BP) values, global constructive work (GCW), global work index (GWI), global work efficiency (GWE), and global wasted work (GWW) were calculated using EchoPAC software (version 204). Considering a mean [±SD] GLS of −16.3±2.8%, the mean [±SD] GWI, GCW, GWW, and GWE was 698.7±147.9 mmHg%, 1,008.5±200.1 mmHg%, 58.1±28.1 mmHg%, and 93.1±2.9%, respectively. All MCW parameters in newborns were lower than those previously reported in children and adults. However, GWI and GCW were more closely correlated with BP and GLS, as in adulthood and children. Estimation of the correlation between MCW and the frame rate index revealed no significant correlations among MCW parameters.

Conclusions: Cardiac function in newborns was evaluated by assessing MCW. With the establishment of reference ranges and normative MCW data for newborns, routine clinical use and rotational mechanics are likely to become increasingly common. Future studies are needed to determine whether MCW is useful in screening for cardiac illness among newborns.

Impact of hypertensive disorders of pregnancy on respiratory outcomes in extremely and very preterm infants: A population-based study in Japan

OBJECTIVES

We aimed to evaluate the impact of hypertensive disorders of pregnancy (HDP) on short- and medium-term respiratory outcomes in extremely and very preterm infants using the Neonatal Research Network of Japan database.

STUDY DESIGN

This was a population-based retrospective study of preterm infants weighing ≤ 1500 g born between 22 and 31 weeks of gestation between 2003 and 2017. After 1:1 stratification matching by four factors (maternal age, gestational age, parity, and year of delivery), a total of 5137 infants in each group (HDP and non-HDP groups) were selected.

MAIN OUTCOME MEASURES

The association between HDP and various respiratory outcomes was evaluated using univariate and multivariate logistic regression analyses.

RESULTS

In the multivariate analyses, HDP was associated with higher odds for respiratory distress syndrome (RDS) (odds ratio 1.83, 95% confidence interval [1.65-2.03]), but reduced odds of persistent pulmonary hypertension of the newborn (PPHN) (0.34 [0.26-0.46]) and inhaled nitric oxide use (0.43 [0.33-0.55]). Although HDP was associated with an increased risk of chronic lung disease (CLD) in the univariate analysis, this association was not significant after adjustment for covariates (0.94 [0.83-1.07]). No significant association was found between HDP and home oxygen therapy (HOT) and medium-term oxygen use.

CONCLUSION

The impact of maternal HDP largely differed depending on respiratory disorders and respiratory support. HDP was associated with higher odds of RDS but reduced odds of PPHN. The risks for CLD, HOT, and medium-term respiratory outcomes in the HDP group were comparable to those in the non-HDP group.

Persistent Pulmonary Hypertension: A Look Into the Future Therapy

Persistent pulmonary hypertension (PPHN) of the newborn is a lung parenchymal disorder that causes a wide range of hemodynamic changes in the newborn's systemic circulation. Arising from a multifactorial web of etiology, PPHN is one of the most common reasons for neonatal intensive care unit hospitalization and is associated with increased morbidity and mortality. Historically, multiple treatment modalities have been explored, ranging from oxygen and surfactant therapy to newer upcoming medications like magnesium sulfate and adenosine. This review article has discussed the pathogenesis of PPHN and its relationship with the clinical implications of PPHN, such as heart failure and so on. This article has also explored the diagnostic guidelines and analyzed the existing and the upcoming modalities for treating PPHN.

Clinical Efficacy and Safety of Different Doses of Sildenafil in the Treatment of Persistent Pulmonary Hypertension of the Newborn: A Network Meta-analysis

Objective: To evaluate the efficacy and safety of different doses of sildenafil for persistent pulmonary hypertension of the newborn (PPHN) with Bayesian random effects network meta-analysis.

Methods: We searched Chinese and English databases for randomized controlled trials (RCTs) concerning sildenafil in newborns with persistent pulmonary hypertension from 1998 to December 2020.

Results: Twenty-two RCTs including over 2131 patients were included. Sildenafil was administered by nasal feeding at 0.3–2 mg/kg every 4–6 h. The network meta-analysis revealed that 1.5 mg/kg of sildenafil led to a significant decrease in pulmonary artery systolic pressure (PASP) compared with 0.3 and 0.6 mg/kg (p < 0.05); 1.5 mg/kg was better than 0.3, 0.5, and 1.0 mg/kg at increasing the partial pressure of oxygen (PaO₂) (p < 0.05); 1.5 mg/kg was better than 0.5, 0.6 and 1.0 mg/kg at reducing the partial pressure of carbon dioxide (PaCO₂) (p < 0.05); and 1.2 mg/kg was better than 0.3, 0.5 and 1.0 mg/kg at increasing the arterial oxygen saturation (SaO₂) (p < 0.05). The surface under the cumulative ranking analysis (SUCRA) results showed that 1.5 mg/kg had the best effect in reducing PASP (SUCRA = 92.0%, moderate certainty evidence) and PaCO₂ (91.1%) and increasing PaO₂ (SUCRA = 79.3%, moderate certainty evidence), 2.0 mg/kg had the best effect in increasing SaO₂ (SUCRA = 88.6%, moderate certainty evidence) and total effective rate (SUCRA = 93.5%, low certainty of evidence)). No severe adverse effects were observed with the different doses of sildenafil.

Conclusion: Different doses of sildenafil can significantly improve PPHN, and 1.5 mg/kg of sildenafil has better clinical efficacy and does not increase the probability of adverse reactions.

Pediatric Pulmonary Hypertension: Definitions, Mechanisms, Diagnosis, and Treatment

Pediatric pulmonary hypertension (PPH) is a multifactorial disease with diverse etiologies and presenting features. Pulmonary hypertension (PH), defined as elevated pulmonary artery pressure, is the presenting feature for several pulmonary vascular diseases. It is often a hidden component of other lung diseases, such as cystic fibrosis and bronchopulmonary dysplasia. Alterations in lung development and genetic conditions are an important contributor to pediatric pulmonary hypertensive disease, which is a distinct entity from adult PH. Many of the causes of pediatric PH have prenatal onset with altered lung development due to maternal and fetal conditions. Since lung growth is altered in several conditions that lead to PPH, therapy for PPH includes both pulmonary vasodilators and strategies to restore lung growth. These strategies include optimal alveolar recruitment, maintaining physiologic blood gas tension, nutritional support, and addressing contributing factors, such as airway disease and gastroesophageal reflux. The outcome for infants and children with PH is highly variable and largely dependent on the underlying cause. The best outcomes are for neonates with persistent pulmonary hypertension (PPHN) and reversible lung diseases, while some genetic conditions such as alveolar capillary dysplasia are lethal. © 2021 American Physiological Society. Compr Physiol 11:2135-2190, 2021.

COVID-19 during pregnancy should we really worry from vertical transmission or rather from fetal hypoxia and placental insufficiency? A systematic review

Background

COVID-19 is the largest outbreak to strike humanity. The wide scale of fatalities and morbidities lead to a concurrent pandemic of uncertainty in scientific evidence. Conflicting evidences are released on daily basis about the neonatal outcomes of COVID-19-positive mothers. The aim of this study was to use the relevant case reports and series to determine the percentage of newborns who test positive for COVID-19 who are born to COVID-19-positive mothers. Secondary outcomes included examining laboratory abnormalities among COVID-19-positive neonates, and any depicted placental abnormalities in COVID-19-positive mothers. For this purpose, systematic review was performed on all studies reporting primary data on fetus-mother pairs with COVID-19. Data bases were searched for studies that met our inclusion and exclusion criteria.

Results

Final screening revealed 67 studies, from which the primary data of 1787 COVID-19 mothers were identified and had their pregnancy outcome analyzed. Only 2.8% of infants born to COVID-19-positive mothers tested positive, and this finding is identical to percentages reported in former Coronaviridae outbreaks, whereas 20% manifested with intrauterine hypoxia alongside placental abnormalities suggestive of heavy placental vaso-occlusive involvement.

Conclusions

These findings suggest that while vertical transmission is unlikely, there appears to be an underlying risk of placental insufficiency due to the prothrombotic tendency observed in COVID-19 infection. Guidelines for proper prophylactic anticoagulation in COVID-positive mothers need to be established.

Persistent pulmonary hypertension in neonates with perinatal asphyxia and therapeutic hypothermia: a frequent and perilous combination

OBJECTIVES

(1) To investigate whether neonates with perinatal asphyxia and therapeutic hypothermia more often developed PPHN compared to a control group with perinatal asphyxia not treated with hypothermia; (2) To identify risk factors for severe PPHN during hypothermia and evaluate short-term outcome.

METHODS

This single-center retrospective cohort study included (near-)term neonates with perinatal asphyxia admitted between 2004 and 2016. Neonates with perinatal asphyxia and hypothermia were compared to a historical control group without hypothermia. Primary outcome was PPHN, defined as severe hypoxemia requiring mechanical ventilation and inhaled nitric oxide, confirmed by echocardiography. Short-term adverse outcome was defined as mortality within one month and/or severe brain injury on MRI.

RESULTS

Incidence of PPHN was 23% (26/114) in the hypothermia group and 11% (8/70) in controls. In multivariate analysis, PPHN was 2.5 times more common among neonates with hypothermia. Neonates developing PPHN during hypothermia often had higher fraction of inspired oxygen at baseline. PPHN was not associated with a higher risk of severe brain injury. However, early mortality was higher and three infants died due to severe refractory PPHN during hypothermia.

CONCLUSIONS

In this study PPHN occurred more often since the introduction of therapeutic hypothermia. This was usually reversible and did not lead to overall increased adverse outcome. However, in individual cases with PPHN deterioration occurred rapidly. In such cases the benefits of hypothermia should be weighed against the risk of a complicated, fatal course.

Hypoxia in utero increases the risk of pulmonary hypertension in rat offspring and is associated with vasopressin type‑2 receptor upregulation

Pulmonary hypertension (PH) in newborns and adults is a disease that can lead to right heart failure and result in a shorter lifespan. PH was induced by maintaining pregnant rats in a hypoxic chamber for 4 h twice a day, from days 7–21 of pregnancy. Hypoxia was confirmed by a decrease in the partial pressure of oxygen (PaO₂) and the oxygen saturation (SaO₂) of arterial blood in the aorta. The body weight of newborns from hypoxic rats was ~20% decreased compared with the control newborns of normoxic rats. The vascular wall thickness/vascular diameter values of hypoxia treated pubs were increased compared with that of control newborns 7 days after birth; however, it decreased to similar levels than in the control group after 3 months, and then further decreased to significantly lower levels than in the control group at 6 months after birth. At birth, the lung tissues of newborns from hypoxic rats exhibited an increase in the levels of mRNA and proteins associated with PH such as HIF-1α, HIF-2α, V2R, TGF-β, TNF-α, Ang-2 and α-SMA. At 3 and 6 months after birth, the levels of both V2R mRNA and protein in offspring from hypoxic rats were at least 2-fold higher, whereas the expression of all other factors decreased compared with the control offspring. By contrast, HIF-2α and Ang-2 expression levels were significantly increased in the 6-month-old control offspring from normoxic rats. V2R overexpression in pups induced by hypoxia in maternal rats was sustained until their adulthood. V2R may be a marker for detecting PH.

Full-Term Neonatal Respiratory Distress and Chronic Lung Disease

Respiratory distress occurs in 5% to 7% of live births at term gestation. Most cases are mild and transient and can be attributed to transient tachypnea of the newborn or "wet lung." Severe respiratory distress is often due to nonpulmonary causes such as sepsis or congenital heart disease. Occasionally, term neonatal respiratory distress is associated with an inherited primary lung disease such as primary ciliary dyskinesia or surfactant metabolism defects. These lung diseases have characteristic presentations in the neonatal period and are important to recognize, as they necessitate different management approaches and have lifelong implications. Suspicion for these diseases should prompt referral to a pediatric pulmonologist. [Pediatr Ann. 2019;48(4):e175-e181.].

Hydrops Fetalis and Persistent Pulmonary Hypertension in a Neonate with Anti-E Alloimmunization

Anti-E alloimmunization is the third most common cause of neonatal hemolytic disease, typically causing mild to moderate hemolytic anemia. We report an unusual case of severe hydrops fetalis and persistent pulmonary hypertension (PPHN) in a neonate with anti-E alloimmunization. Our case emphasizes the importance of close surveillance for development of severe fetal hemolytic anemia and possible need for antenatal intervention. These neonates may also need vigilant monitoring for PPHN.

Dynamic changes of pulmonary arterial pressure in perinatal neonates with pulmonary and extrapulmonary acute lung injury/respiratory distress syndrome

This study aims to explore the dynamic changes of pulmonary arterial pressure (PAP) and its clinical significance in prenatal neonates with pulmonary and extra-pulmonary acute lung injury/respiratory distress syndrome (ALI/ARDS).A prospective study was conducted in the Neonate Intensive Care Unit (NICU) between May 2015 and April 2017. A total of 78 prenatal neonates with ALI/ARDS were selected and divided into 2 groups: pulmonary group (n = 37) and extra-pulmonary group (n = 41). These neonates were further divided into 3 groups according to the OSI index: mild, moderate, and severe groups. The dynamic changes of PAP were observed in these neonates. In the moderate and severe groups, PAP was significantly higher in neonates with pulmonary ALI/ADDS (ALI/ARDSp) than in neonates with extrapulmonary ALI/ARDS(ALI/ARDSexp) (62.5 ± 5.4 vs 68.0 ± 6.5, 54.7 ± 5.9 vs 64.2 ± 4.9; t = 3.264, 3.123; P = .004,.039). Furthermore, PAP was higher in neonates with ALI/ADDSp in the severe group, compared with those in the moderate group (t = 2.420, P < .05). There was significant difference among the 3 subgroups of neonates with ALI/ADDSexp (F = 60.100, P = .000). PAP was positively correlated with the OSI index (r = 0.823). The overall dynamic PAP monitoring results revealed that PAP was higher in the pulmonary group than that in the extrapulmonary group, and this exhibited a gradually decreasing trend as the condition of the subject improved.PAP in perinatal neonates with ALI/ARDS increases in varying degrees, and its extent was related to the severity of the illness. PAP was significantly higher in neonates with ALI/ADDSp than in neonates with ALI/ADDSexp. This can be used as a monitoring indicator for the severity of illness.

Maternal-pup interaction disturbances induce long-lasting changes in the newborn rat pulmonary vasculature

The factors accounting for the pathological maintenance of a high pulmonary vascular (PV) resistance postnatally remain elusive, but neonatal stressors may play a role in this process. Cross-fostering in the immediate neonatal period is associated with adult-onset vascular and behavioral changes, likely triggered by early-in-life stressors. In hypothesizing that fostering newborn rats induces long-lasting PV changes, we evaluated them at 14 days of age during adulthood and compared the findings with animals raised by their biological mothers. Fostering resulted in reduced maternal-pup contact time when compared with control newborns. At 2 wk of age, fostered rats exhibited reduced pulmonary arterial endothelium-dependent relaxation secondary to downregulation of tissue endothelial nitric oxide synthase expression and tetrahydrobiopterin deficiency-induced uncoupling. These changes were associated with neonatal onset-increased ANG II receptor type 1 expression, PV remodeling, and right ventricular hypertrophy that persisted into adulthood. The pulmonary arteries of adult-fostered rats exhibited a higher contraction dose response to ANG II and thromboxane A2, the latter of which was abrogated by the oxidant scavenger Tempol. In conclusion, fostering-induced neonatal stress induces long-standing PV changes modulated via the renin-angiotensin system.

Antidepressant use late in pregnancy and risk of persistent pulmonary hypertension of the newborn

IMPORTANCE

The association between selective serotonin reuptake inhibitor (SSRI) antidepressant use during pregnancy and risk of persistent pulmonary hypertension of the newborn (PPHN) has been controversial since the US Food and Drug Administration issued a public health advisory in 2006.

OBJECTIVE

To examine the risk of PPHN associated with exposure to different antidepressant medication classes late in pregnancy.

DESIGN AND SETTING

Cohort study nested in the 2000-2010 Medicaid Analytic eXtract for 46 US states and Washington, DC. Last follow-up date was December 31, 2010.

PARTICIPANTS

A total of 3,789,330 pregnant women enrolled in Medicaid from 2 months or fewer after the date of last menstrual period through at least 1 month after delivery. The source cohort was restricted to women with a depression diagnosis and logistic regression analysis with propensity score adjustment applied to control for potential confounders. EXPOSURES FOR OBSERVATIONAL STUDIES: SSRI and non-SSRI monotherapy use during the 90 days before delivery vs no use.

MAIN OUTCOMES AND MEASURES

Recorded diagnosis of PPHN during the first 30 days after delivery.

RESULTS

A total of 128,950 women (3.4%) filled at least 1 prescription for antidepressants late in pregnancy: 102,179 (2.7%) used an SSRI and 26,771 (0.7%) a non-SSRI. Overall, 7630 infants not exposed to antidepressants were diagnosed with PPHN (20.8; 95% CI, 20.4-21.3 per 10,000 births) compared with 322 infants exposed to SSRIs (31.5; 95% CI, 28.3-35.2 per 10,000 births), and 78 infants exposed to non-SSRIs (29.1; 95% CI, 23.3-36.4 per 10,000 births). Associations between antidepressant use and PPHN were attenuated with increasing levels of confounding adjustment. For SSRIs, odds ratios were 1.51 (95% CI, 1.35-1.69) unadjusted and 1.10 (95% CI, 0.94-1.29) after restricting to women with depression and adjusting for the high-dimensional propensity score. For non-SSRIs, the odds ratios were 1.40 (95% CI, 1.12-1.75) and 1.02 (95% CI, 0.77-1.35), respectively. Upon restriction of the outcome to primary PPHN, the adjusted odds ratio for SSRIs was 1.28 (95% CI, 1.01-1.64) and for non-SSRIs 1.14 (95% CI, 0.74-1.74).

CONCLUSIONS AND RELEVANCE

Evidence from this large study of publicly insured pregnant women may be consistent with a potential increased risk of PPHN associated with maternal use of SSRIs in late pregnancy. However, the absolute risk was small, and the risk increase appears more modest than suggested in previous studies.

Risk factors associated with intracranial hemorrhage in neonates with persistent pulmonary hypertension on ECMO

Background

Up to 40% of infants with persistent pulmonary hypertension (PPHN) remains refractory to conventional therapies, and extracorporeal membrane oxygenation (ECMO) is offered as an effective support for this group. However, ECMO is a highly invasive and risky procedure with devastating complications such as intracranial hemorrhage (ICH). In this study, we aimed to determine the risk factors for ICH in infants with PPHN.

Methods

A case-control study of patients admitted to the pediatric intensive care unit (PICU) with PPHN requiring ECMO support was conducted. The study was carried out at a 25-bed PICU in large urban tertiary care children’s hospital. A total number of 32 subjects were studied. Patients with and without ICH during ECMO were evaluated for activated clotting time (ACT), heparin dosing, platelet count, coagulation profile such as activated partial thromboplastin time (aPTT), prothrombin time (PT), international normalized ratio (INR), fibrinogen level, vital signs including heart rate and mean arterial pressure (MAP), transfusion history, gestational age, and severity of pre-ECMO illness as possible risk factors.

Results

Low fibrinogen level (115 ± 13 mg/dl) and low platelet counts (37.4 ± 18.3 Thousand/μl) were associated with higher incidence of ICH (p = 0.009 and p = 0.005, respectively). Elevated MAP (69 ± 4.34 mmHg) was also noticed in ICH patients (p = 0.006).

Conclusions

Results demonstrated that low fibrinogen level and low platelet count were associated with ICH in PPHN patients on ECMO. While on ECMO support, maintaining fibrinogen and platelet counts within normal ranges seems crucial to prevent ICH in PPHN patients. This is the first report identifying low fibrinogen level among the risk factors for ICH in infants with PPHN on ECMO support.

Molecular physiopathogenetic mechanisms and development of new potential therapeutic strategies in persistent pulmonary hypertension of the newborn

Persistent pulmonary hypertension of the newborn (PPHN) is a cyanogenic plurifactorial disorder characterized by failed postnatal drop of pulmonary vascular resistance and maintenance of right-to-left shunt across ductus arteriosus and foramen ovale typical of intrauterine life. The pathogenesis of PPHN is very complex and can result from functional (vasoconstriction) or structural (arteriolar remodeling, reduced pulmonary vessels density) anomalies of pulmonary circulation. Etiopathogenetic factors heterogeneity can strongly condition therapeutical results and prognosis of PPHN that is particularly severe in organic forms that are usually refractory to selective pulmonary vasodilator therapy with inhaled nitric oxide. This paper reports the more recent acquisitions on molecular physiopathogenetic mechanisms underlying functional and structural forms of PPHN and illustrates the bases for adoption of new potential treatment strategies for organic PPHN. These strategies aim to reverse pulmonary vascular remodeling in PPHN with arteriolar smooth muscle hypertrophy and stimulate pulmonary vascular and alveolar growth in PPHN associated with lung hypoplasia.In order to restore lung growth in this severe form of PPHN, attention is focused on the results of studies of mesenchymal stem cells and their therapeutical paracrine effects on bronchopulmonry dysplasia, a chronic neonatal lung disease characterized by arrested vascular and alveolar growth and development of pulmonary hypertension.

Persistent pulmonary hypertension of the newborn associated with severe congenital anemia of various etiologies

Among the many associated features of persistent pulmonary hypertension of the neonate (PPHN), severe congenital anemia has been described only occasionally and is not included in the list of conditions that may cause PPHN in the neonate. We describe the clinical course of a group of 12 full-term neonates with PPHN and congenital anemia due to congenital dyserythropoietic anemia (7/12), α thalasemia (1/12), Diamond-Blackfan (1/12), and epsilon gamma delta beta thalassemia (3/12). The association of congenital anemia and PPHN is more common than previously thought; it can exist with various etiologies and severity of anemia. Congenital anemia has not been described until now as a cause or risk factor for PPHN; it should be considered as such alone or in combination with other known causes to be recognized early and treated appropriately to improve outcome. In families with known cases of congenital anemia due to the above-mentioned diagnosis, closer prenatal follow-up should be offered to anticipate possible fetal distress and/or fetal anemia and PPHN after birth.

An unusual cause of refractory persistent pulmonary hypertension of the newborn: anomalous origin of one pulmonary artery

Persistent pulmonary hypertension of the newborn is a source of considerable mortality and morbidity. Anomalous origin of one pulmonary artery, an uncommon congenital cardiac malformation, is a rare cause of persistent pulmonary hypertension. Here, we report the case of a patient with an anomalous origin of one pulmonary artery from the innominate artery who presented with persistent pulmonary hypertension refractory to treatment.

[Antiphospholipid syndrome and pregnancy]

Antiphospholipid syndrome is characterized by arterial and venous thromboembolic events and persistent laboratory evidence of antiphospholipid antibodies. Obstetric complications such as recurrent miscarriage, early delivery, oligohydramnios, prematurity, intrauterine growth restriction, fetal distress, fetal or neonatal thrombosis, pre-eclampsia/eclampsia, and HELLP syndrome are also hallmarks of antiphospholipid syndrome. This syndrome is one of the diseases associated with the most severe thrombotic risk. Changes in the hemostatic system during normal pregnancy also result in a hypercoagulable state resulting in elevated thrombotic risk. Thromboembolic events are responsible of the vast majority of maternal and fetal deaths. Administration of appropriate thromboprophylaxis helps prevent thromboembolic complications during pregnancy in women with antiphospholipid syndrome and also give birth to healthy children. It is important to centralize the medication and management of these patients. It helps in the thoughtful care of these pregnant women encountering serious problems.