Increased incidence of respiratory distress syndrome in neonates of mothers with abnormally invasive placentation

Customizing EV-CATCHER to Purify Placental Extracellular Vesicles from Maternal Plasma to Detect Placental Pathologies

Placenta Accreta Spectrum (PAS) is a life-threatening condition in which placental trophoblastic cells abnormally invade the uterus, often up to the uterine serosa and, in extreme cases, tissues beyond the uterine wall. Currently, there is no clinical assay for the non-invasive detection of PAS, and only ultrasound and MRI can be used for its diagnosis. Considering the subjectivity of visual assessment, the detection of PAS necessitates a high degree of expertise and, in some instances, can lead to its misdiagnosis. In clinical practice, up to 50% of pregnancies with PAS remain undiagnosed until delivery, and it is associated with increased risk of morbidity/mortality. Although many studies have evaluated the potential of fetal biomarkers circulating in maternal blood, very few studies have evaluated the potential of circulating placental extracellular vesicles (EVs) and their miRNA contents for molecular detection of PAS. Thus, to purify placental EVs from maternal blood, we customized our robust ultra-sensitive immuno-purification assay, termed EV-CATCHER, with a monoclonal antibody targeting the membrane Placental Alkaline Phosphatase (PLAP) protein, which is unique to the placenta and present on the surface of placental EVs. Then, as a pilot evaluation, we compared the miRNA expression profiles of placental EVs purified from the maternal plasma of women diagnosed with placenta previa (controls, n = 16); placenta lying low in uterus but not invasive) to those of placental EVs purified from the plasma of women with placenta percreta (cases, n = 16), PAS with the highest level of invasiveness. Our analyses reveal that miRNA profiling of PLAP+ EVs purified from maternal plasma identified 40 differentially expressed miRNAs when comparing these two placental pathologies. Preliminary miRNA pathway enrichment and gene ontology analysis of the top 14 upregulated and top nine downregulated miRNAs in PLAP+ EVs, purified from the plasma of women diagnosed with placenta percreta versus those diagnosed with placenta previa, suggests a potential role in control of cellular invasion and motility that will require further investigation.

Periodic breathing in clinically stable very preterm infants

OBJECTIVE

We aimed to investigate the frequency and severity of periodic breathing (PB) in clinically stable very preterm infants and identify infant and maternal factors associated with increased time spent and severity of PB in these infants.

METHOD

Thirty-eight infants (28-32 weeks gestational age) who were ≥3 days off noninvasive respiratory support, were studied for 2-3 h with a daytime sleep study at 31-36 weeks postmenstrual age. Percent total sleep time spent in PB (%TSTPB) and time spent with SpO₂ <90%, <80%, and cerebral oxygenation <55% during PB were calculated. Infant and maternal characteristics were correlated with %TSTPB and hypoxia during PB.

RESULTS

The majority of infants (92%) had at least one episode of PB and infants spent a median 9.1 [interquartile range: 1.2, 15.5] %TSTPB. 80%, 37%, and 37% of infants experienced SpO₂ <90%, <80% and cerebral oxygenation <55%, respectively, during PB. Shorter duration of respiratory support, multigravida, multiparity, and maternal vitamin D deficiency were associated with higher %TSTPB. Multigravida, shorter duration on respiratory support, apnea of prematurity, and resuscitation at birth were associated with hypoxia during PB.

CONCLUSIONS

The majority of very preterm infants exhibited PB when they were off respiratory support and considered clinically stable. The time spent in PB was very variable between infants and was associated with significant hypoxia in some infants. Fewer days spent on respiratory support was associated with both increased frequency and severity of PB. However, the potential contribution of PB to neurocognitive outcomes remains uncertain and warrants further investigations.

Impact of placenta accreta spectrum (PAS) pathology on neonatal respiratory outcomes in cesarean hysterectomies

OBJECTIVE

Placenta accreta spectrum (PAS) is a continuum of disorders characterized by the pathologically adherent placenta to the uterine myometrium. Delivery by cesarean hysterectomy at 34-36 weeks is recommended to mitigate the risks of maternal morbidity. Iatrogenic preterm delivery, has potential neonatal implications; late preterm infants are at risk for significant respiratory morbidity. Neonatal outcomes in PAS neonates are not well described in the literature, we aimed to investigate these outcomes.

METHODS

A case-control study was performed with 107 cases of pathology-confirmed PAS patients with singleton, non-anomalous, viable pregnancies, compared to 76 cases of placenta previa with prior cesarean section who underwent repeat cesarean section. All patients were delivered through our institution's Placenta Accreta Program from 2005 to 2020. Rates of neonatal respiratory morbidity and related outcomes were analyzed.

RESULTS

Maternal characteristics and antenatal complications were similar between groups, as were gestational age, steroid exposure, and emergent delivery. PAS was associated with increased use of general anesthesia (20 vs. 54%, p = .001), larger estimated blood loss (1875 vs. 6077 ml, p = .008), and longer post-operative stays (4.8 vs. 7.3 days, p = .01). PAS was also associated with neonatal increased rates of high flow nasal cannula (HFNC) (41 vs. 58%, p = .02), intubation (17 vs. 37%, p = .008), and duration of respiratory support (0 vs. 2 days, p = .03). There were no differences in rates of continuous positive airway pressure (CPAP)/positive pressure ventilation (PPV) (21 vs. 22%, p = .85), anemia, hyperbilirubinemia, or NICU length of stay. Multivariate analysis adjusting for general anesthesia demonstrated this variable confounded the impact of PAS pathology in respiratory outcomes the risk of the respiratory composite (adjusted odds ratio (aOR) 0.57, 95% CI [0.11, 2.82]), use of HFNC (aOR 0.33, 95% CI [0.08-1.48]), and intubation (aOR 1.29, 95% CI [0.25-6.75]), were no longer significant.

CONCLUSIONS

Based on these results, we conclude that PAS neonates have higher rates of respiratory morbidity and that general anesthesia is a significant contributor to these respiratory outcomes. This is important for the antenatal counseling of cases of PAS, especially if general anesthesia is anticipated or requested. Furthermore, it supports efforts to limit general anesthesia exposure of neonates when necessary.

Effect of anesthesia selection on neonatal outcomes in cesarean hysterectomies for placenta accreta spectrum (PAS)

OBJECTIVES

Optimal treatment for placenta accreta spectrum (PAS) is late-preterm cesarean hysterectomy to minimize maternal morbidity. This study aims to assess the impact of surgical planning during this gestational age on neonates as a key part of the pregnancy dyad.

METHODS

A retrospective cohort analysis was performed of 115 singleton, non-anomalous pregnancies complicated by PAS at the University of Texas Health San Antonio Placenta Accreta program from 2005 to 2020. Univariate and multivariate analyses were performed to identify the individual impact of variables such as anesthesia selection, advancing gestational age and operative characteristics.

RESULTS

With regards to neonatal intubation, on multivariate analysis, neuraxial anesthesia (OR=0.09, [95% CI 0.02, 0.37]) and advancing gestational age (OR=0.49 [95% CI 0.34, 0.71]) were independent protective factors. In addition, NICU length of stay was directly impacted by neuraxial anesthesia (IRR=0.73, [95% CI 0.55, 0.97]) and advancing gestational age (IRR=0.80 [95% CI 0.76, 0.84]), resulting in shorter NICU admissions.

CONCLUSIONS

As gestational age at delivery may not be modifiable in cases of PAS, the utilization of neuraxial anesthesia (as oppose to general anesthesia) presents a modifiable intervention which may optimize neonatal outcomes from cesarean hysterectomy.

The Role and Clinical Value of Optimized Fetal Main Pulmonary Artery Doppler Parameters in the Diagnosis and Prognosis Monitoring of Neonatal Respiratory Distress Syndrome

Objective

A retrospective study was conducted to explore the role and clinical value of optimized fetal main pulmonary artery Doppler parameters in the diagnosis and prognosis monitoring of neonatal respiratory distress syndrome (NRDS).

Methods

Pregnant women admitted to our hospital for delivery from March 2019 to June 2021 were included in the study. There were 372 singleton pregnant women who voluntarily underwent ultrasound and Doppler examinations with informed consent for the study. The AT/ET ratio of the middle segment of the main pulmonary artery, the middle part of the left (or right) pulmonary artery, and the proximal segment of the intrapulmonary artery was measured by ultrasonic Doppler. According to the outcome of the newborn, it was divided into NRDS group (n =90) and non-NRDS group (n =282) to compare the differences of fetal AT/ET ratio at three Doppler sampling locations and the differences of fetal AT/ET ratio in different gestational weeks. Using Pearson's correlation analysis, the correlation among the Doppler parameters of fetal main pulmonary artery, the ratio of AT and AT/ET, gestational weeks, and the efficiency of prenatal prediction of NRDS was evaluated by receiver-operating characteristic (ROC). In addition, the diagnostic efficiency of fetal main pulmonary artery Doppler parameter AT/ET ratio and amniotic fluid method for prenatal prediction of NRDS was compared.

Results

Compared with the non-NRDS group, the gestational age, gestational age at delivery, and birth weight in the NRDS group were significantly lower than those in the non-NRDS group. The 1 min Apgar score of newborns was less than 7, and the proportion of newborns transferred to NICU was significantly higher than that in the control group. Compared with non-NRDS group, AT was significantly shortened, AT/ET ratio was significantly decreased, and ET was significantly prolonged in NRDS group. The fetal aortic blood flow parameters AT, ET, and AT/ET ratio in different gestational weeks were significantly different among the three groups. The AT/ET ratio in the middle segment of the aorta in NRDS group was lower than that in non-NRDS group. The ratio of AT/ET was still correlated with the occurrence of postpartum NRDS. The AUC value of NRDS predicted by AT/ET ratio was 0.984. In the combined determination of amniotic fluid Lh and S ratio and PG, the diagnostic accuracy of prenatal prediction of neonatal respiratory distress syndrome was 100.005%, 98.43%, and 95.56%, respectively. The accuracy of fetal aortic AT/ET ratio in prenatal prediction of neonatal respiratory distress syndrome was 100.005%, 95.28%, and 95.57%, respectively. The order of Kappa coefficient from high to low was amniotic fluid PG/L/S ratio, fetal main pulmonary artery blood flow parameter AT/ET ratio, amniotic fluid L/S ratio, OD650, amniotic fluid PG, and foam test.

Conclusion

Fetal main pulmonary artery Doppler AT/ET ratio may be a very potential parameter for prenatal noninvasive prediction of NRDS. The fetal main pulmonary artery Doppler flow spectrum may be a very potential alternative to amniocentesis to evaluate FLM.

Prediction of extubation readiness using lung ultrasound in preterm infants

We aimed to test the hypothesis that a lung ultrasound severity score (LUS) and assessment of left ventricular eccentricity index of the interventricular septum (LVEI) by focused heart ultrasound can predict extubation success in mechanically ventilated infants. We conducted a prospective study on premature infants less than 34 weeks' of gestation. LUS was performed on postnatal Days 3 and 7 by an investigator who was masked to infants' ventilator parameters. LVEI and pulmonary artery pressure (PAP) were measured at postnatal Day 3. A receiver operator curve was constructed to assess the ability to predict extubation success. Spearman correlation was performed between LVEI and PAP. A total of 104 studies were performed to 66 infants; of them 39 had mild and 65 had moderate-severe lung disease. LUS predicted extubation success with a sensitivity and a specificity of 91% and 69%, respectively. Area under the curve was 0.83 (CI: 0.75-0.91). LVEI did not differ between infants that succeeded and failed extubation. It correlated with PAP during systole (r = .66). We conclude that LUS predicts extubation success in mechanically ventilated preterm infants whereas LVEI correlates with high PAP.

Efficacy comparison of high-frequency oscillatory ventilation with continuous nasal positive airway pressure in neonatal respiratory distress syndrome treatment

OBJECTIVES

To compare the treatment efficacy of high-frequency oscillatory ventilation (HFOV) with nasal continuous positive airway pressure (NCPAP) in the treatment of neonatal respiratory distress syndrome (NRDS) and its effect on the expression of high-mobility group protein B1 (HMGB1).

METHODS

A total of 180 infants with NRDS admitted to our hospital were included and randomly assigned into the HFOV group (receiving conventional therapy and HFOV), the NCPAP group (receiving conventional therapy and NCPAP), and the conventional group (receiving conventional therapy). Qi and blood indicators, heart rate, respiratory frequency, PCO₂, and PaO₂ were observed and recorded before and after treatment, together with complications after treatment. ELISA was performed for HMGB1 Results: A distinctly lower partial pressure of carbon dioxide (PCO₂) but higher arterial partial pressure of oxygen (PaO₂) was observed in the HFOV and NCPAP groups than in the conventional group (P < 0.05), whereas infants in the HFOV group exhibited slight differences in these two indicators from their counterparts in the NCPAP group (P > 0.05). The serum HMGB1 levels in both groups were significantly higher than those in the conventional group (P < 0.05).

DISCUSSION

Both HFOV and NCPAP are feasible in the treatment of NRDS and may play a role in the inhibition of HMGB1.

Effect of pulmonary surfactant on the prevention of neonatal respiratory distress syndrome in premature infants

OBJECTIVE

To investigate the effect of pulmonary surfactant on the prevention of neonatal respiratory distress syndrome (NRDS) in premature infants.

METHODS

A total of 216 premature infants in our hospital were selected. According to the guardian's choice, premature infants were grouped into treatment with pulmonary surfactant (PS) combined with nasal continuous positive airway pressure (NCPAP; the observation group) and treatment with NCPAP alone (the control group). The observation group was further divided into the young gestational age group (group A, 40 cases) and old gestational age group (group B, 74 cases), while the control group was divided into the young gestational age group (group C, 35 cases) and old gestational age group (group D, 67 cases). The incidence of NRDS, the first and second use of PS, the number of cases with mechanical ventilation, use of oxygen time, length of hospital stay and complications were observed.

RESULTS

The incidence of NRDS in the observation group was lower than that in the control group, but the first use rate of PS was higher than in the control group (P<0.05). The incidence of NRDS in group A was lower than that in the other three groups (P<0.001), while the mechanical ventilation rate in group C was higher than that in the other three groups (P<0.001). Use of oxygen time and length of hospital stay in groups A and C were higher than those in groups B and D (P<0.001). The mortality rate of group A was lower than that of group C (P<0.05). There was no difference in complications among patients with different gestational ages (P>0.05).

CONCLUSION

Early use of PS can prevent the incidence of NRDS in preterm infants, significantly reduce the incidence of NRDS in neonates with young gestational age. It can also improve the survival rate of patients with young gestational age without increasing the incidence of complications.

The burden of hyaline membrane disease, mortality and its determinant factors among preterm neonates admitted at Debre Tabor General Hospital, North Central Ethiopia: A retrospective follow up study

BACKGROUND

Hyaline membrane disease (HMD) is a leading cause of morbidity and mortality in preterm newborn babies. Though, there are studies related to Hyaline membrane disease inclusive of all neonates, studies related to the burden among preterm neonates were limited. In addition, increasing neonatal mortality in Ethiopia could be related to increase in the burden of hyaline membrane disease among preterm neonates. Therefore, this study was aimed to assess the burden of hyaline membrane disease, mortality and its associated factors among preterm neonate admitted at neonatal intensive care unit, North Central Ethiopia.

METHODOLOGY

An institution-based retrospective follow-up study was conducted among 535 preterm neonates admitted at neonatal intensive care unit from January 1, 2014-December 30, 2017. Data were entered into EPi-data 4.2.0.0 and transferred to STATA version 14 statistical software for statistical analysis. Binary logistic regression was used for the analysis. All variables with P-value < 0.25 during bi-variable analysis were considered for multivariable logistic regression. Level of statistical significance was declared at P value ≤0.05.

RESULTS

In the current study, proportion of hyaline membrane disease was 40% (95% CI; 35.8, 44.3) of which 49.5% died. Preterm neonate born with Gestational age of less than 34 weeks of age (Adjusted odd ratio (AOR = 2.64; 95 CI: 1.49, 4.66)), 5th minute Apgar score less than 7 (AOR = 2.2; 95% CI: 1.20, 4.07), and newborn with birth weight of less than 1500 gram (AOR = 2.4, 95% CI: 1.3, 4.3) were predictors of hyaline membrane disease.

CONCLUSIONS

The mean gestational age (±) was 33.46 (±2.55) weeks. The incidence of hyaline membrane disease among preterm admissions was high. Preterm neonate born with gestational age of less than 34 weeks of age, asphyxiated newborns and newborn with birth weight of less than 1500 gram were predictors of hyaline membrane disease. So, emphasis should be given on early screening, follow up and timely interventions for preterm neonate.

Risk factors for respiratory assistance in premature infants

Premature infants are prone to dyspnea after birth due to immature development, and some infants require respiratory assistance. However, the risk factors for respiratory assistance in premature infants are rarely reported. The present study enrolled 3,394 premature infants (665 infants had been provided with respiratory assistance and 2,729 had not used respiratory assistance) to retrospectively analyze the risk factors associated with respiratory aid. The multivariate logistic regression analysis demonstrated that placental abnormality [odds ratio (OR)=1.284; P=0.048], the male sex (OR=0.696; P=0.001), delivery via cesarean section (OR=1.538; P<0.001), low 1-min Apgar score (OR=0.727; P<0.001), low birth weight (OR=0.999; P=0.005) and low gestational age (OR=0.616; P<0.001) were independent risk factors for respiratory assistance in premature infants. Overall, a number of risk factors, including placental abnormality, cesarean section, low 1-min Apgar score, low birth weight and small gestational age, were identified for respiratory assistance in premature infants. By conducting a risk assessment of risk factors at birth and using this information to provide timely respiratory assistance, the survival rates of premature infants may increase.