Neonatal morbidity after documented fetal lung maturity in late preterm and early term infants

Prenatal prediction of respiratory distress syndrome by multimodality approach using 3D lung ultrasound, lung-to-liver intensity ratio tissue histogram and pulmonary artery Doppler assessment of fetal lung maturity

OBJECTIVE

Studying the correlation of different lung parameters, using three-dimensional ultrasound (3D US) with fetal lung maturity (FLM) to predict the development of neonatal respiratory distress syndrome (RDS).

METHODS

Three-dimensional ultrasound was done to record the fetal lung volume (FLV), fetal lung-to-liver intensity ratio (FLLIR) and the main pulmonary artery (MPA) blood flow parameters; pulsatility index (PI), resistive index (RI) and acceleration time-to-ejection time ratio (At/Et), to 218 women between 32 and 40 weeks gestational age within 24 h from labor.

RESULTS

Of 218 fetuses examined, final analysis was done for 143 fetuses. Thirty eight (26.5%) were diagnosed with RDS. The MPA PI and RI were significantly higher in fetuses diagnosed with RDS compared with those without (2.51 ± 0.33 and 0.90 ± 0.03 cm/s versus 1.96 ± 0.20 and 0.84 ± 0.01 cm/s; p value < 0.001 and <0.001 respectively). MPA At/Et was significantly lower (0.24 ± 0.04 vs 0.35 ± 0.04; p value < 0.001). FLLIR was significantly lower (1.04 ± 0.07 vs 1.18 ± 0.11; p value < 0.001), and the mean FLV was significantly smaller (28.23 ± 5.63, vs 38.87 ± 4.68 cm³; p value < 0.001).

CONCLUSION

Main pulmonary artery (PI, RI, At/Et ratio), FLIIR, and mean FLV can be used as reliable predictors of neonatal RDS.

ADVANCES IN KNOWLEDGE

3D ultrasound VOCAL technique, ultrasound tissue histogram and pulmonary artery Doppler are reliable tools for prenatal prediction of fetal lung maturity.

Fisioterapia respiratória não altera agudamente os parâmetros fisiológicos ou os níveis de dor em prematuros com síndrome do desconforto respiratório internados em unidade de terapia intensiva

RESUMO Objetivo: avaliar a ocorrência de alterações fisiológicas adversas agudas e a presença de dor em recém-nascidos prematuros com síndrome do desconforto respiratório internados em uma unidade de terapia intensiva neonatal após a fisioterapia respiratória. Métodos: estudo transversal que avaliou 30 neonatos prematuros em três momentos, sendo eles Momento um (M1), antes da fisioterapia, Momento dois (M2), imediatamente após a fisioterapia, e Momento três (M3), 15 minutos após. Consideraram-se alterações fisiológicas as variações da frequência cardíaca (FC), da frequência respiratória (FR), da saturação periférica de oxigênio (SpO2) e da temperatura corporal. A presença de dor foi avaliada pelas escalas neonatal infant pain scale e neonatal facial coding system. Resultados: houve aumento estatisticamente significativo na FC no M2 quando comparados os três momentos, porém com retorno aos valores basais 15 minutos após a fisioterapia. Outras variáveis fisiológicas (FR, SpO2 e temperatura) e a avaliação da dor não apresentaram alterações significativas. Conclusão: parâmetros fisiológicos e comportamentais permaneceram estáveis após a realização da fisioterapia respiratória, com discretas alterações imediatamente após o procedimento, mas com retorno aos valores basais, indicando que a fisioterapia respiratória não alterou agudamente os sinais vitais e os níveis de dor dos neonatos.

Evaluation of an improved tool for non-invasive prediction of neonatal respiratory morbidity based on fully automated fetal lung ultrasound analysis

The objective of this study was to evaluate the performance of a new version of quantusFLM®, a software tool for prediction of neonatal respiratory morbidity (NRM) by ultrasound, which incorporates a fully automated fetal lung delineation based on Deep Learning techniques. A set of 790 fetal lung ultrasound images obtained at 24 + 0–38 + 6 weeks’ gestation was evaluated. Perinatal outcomes and the occurrence of NRM were recorded. quantusFLM® version 3.0 was applied to all images to automatically delineate the fetal lung and predict NRM risk. The test was compared with the same technology but using a manual delineation of the fetal lung, and with a scenario where only gestational age was available. The software predicted NRM with a sensitivity, specificity, and positive and negative predictive value of 71.0%, 94.7%, 67.9%, and 95.4%, respectively, with an accuracy of 91.5%. The accuracy for predicting NRM obtained with the same texture analysis but using a manual delineation of the lung was 90.3%, and using only gestational age was 75.6%. To sum up, automated and non-invasive software predicted NRM with a performance similar to that reported for tests based on amniotic fluid analysis and much greater than that of gestational age alone.

The role of three-dimensional ultrasonography fetal lung volume measurement in the prediction of neonatal respiratory function outcome

BACKGROUND

Respiratory distress is commonly encountered among premature babies immediately after birth resulting in significant neonatal morbidity or mortality.

OBJECTIVES

To evaluate the possible correlation between three dimensional fetal lung volumes (FLVs) and neonatal respiratory outcomes.

STUDY DESIGN

A cohort study included 100 pregnant women who participated in the study and were divided into two groups; group A (n: 50 - women pregnant ±34-37 weeks) and group B (n: 50 - women pregnant ±37⁺¹ to 40 weeks). A three dimensional measurement of the right fetal lung was made using virtual organ computer-aided analysis (VOCAL) software then correlated to neonatal respiratory functions namely Apgar score at birth and the occurrence of respiratory distress syndrome (RDS).

RESULTS

In group A, FLV was negatively correlated with Apgar score and the occurrence of RDS. In group B, FLV showed no statistical correlation with Apgar score and the occurrence of RDS.

CONCLUSIONS

Three dimensional fetal lung volumes might be an accurate noninvasive predictor for the development of RDS among preterm fetuses.

Neonatal outcomes of elective early-term births after demonstrated fetal lung maturity

BACKGROUND

Studies of early-term birth after demonstrated fetal lung maturity show that respiratory and other outcomes are worse with early-term birth (370-386 weeks) even after demonstrated fetal lung maturity when compared with full-term birth (390-406 weeks). However, these studies included medically indicated births and are therefore potentially limited by confounding by the indication for delivery. Thus, the increase in adverse outcomes might be due to the indication for early-term birth rather than the early-term birth itself.

OBJECTIVE

We examined the prevalence and risks of adverse neonatal outcomes associated with early-term birth after confirmed fetal lung maturity as compared with full-term birth in the absence of indications for early delivery.

STUDY DESIGN

This is a secondary analysis of an observational study of births to 115,502 women in 25 hospitals in the United States from 2008 through 2011. Singleton nonanomalous births at 37-40 weeks with no identifiable indication for delivery were included; early-term births after positive fetal lung maturity testing were compared with full-term births. The primary outcome was a composite of death, ventilator for ≥2 days, continuous positive airway pressure, proven sepsis, pneumonia or meningitis, treated hypoglycemia, hyperbilirubinemia (phototherapy), and 5-minute Apgar <7. Logistic regression and propensity score matching (both 1:1 and 1:2) were used.

RESULTS

In all, 48,137 births met inclusion criteria; the prevalence of fetal lung maturity testing in the absence of medical or obstetric indications for early delivery was 0.52% (n = 249). There were 180 (0.37%) early-term births after confirmed pulmonary maturity and 47,957 full-term births. Women in the former group were more likely to be non-Hispanic white, smoke, have received antenatal steroids, have induction, and have a cesarean. Risks of the composite (16.1% vs 5.4%; adjusted odds ratio, 3.2; 95% confidence interval, 2.1-4.8 from logistic regression) were more frequent with elective early-term birth. Propensity scores matching confirmed the increased primary composite in elective early-term births: adjusted odds ratios, 4.3 (95% confidence interval, 1.8-10.5) for 1:1 and 3.5 (95% confidence interval, 1.8-6.5) for 1:2 matching. Among components of the primary outcome, CPAP use and hyperbilirubinemia requiring phototherapy were significantly increased. Transient tachypnea of the newborn, neonatal intensive care unit admission, and prolonged neonatal intensive care unit stay (>2 days) were also increased with early-term birth.

CONCLUSION

Even with confirmed pulmonary maturity, early-term birth in the absence of medical or obstetric indications is associated with worse neonatal respiratory and hepatic outcomes compared with full-term birth, suggesting relative immaturity of these organ systems in early-term births.

The rate of neonatal respiratory distress syndrome/transient tachypnea in the newborn and the amniotic lamellar body count in twin pregnancies compared with singleton pregnancies

BACKGROUND

Whether or not the period of fetal lung maturity differs between twin and singleton pregnancies has not been clarified. We examined whether or not fetal lung maturity and fetal lung absorption are achieved earlier in twin fetuses than in singleton fetuses.

METHODS

We registered 454 singleton pregnancies and 398 twin pregnancies with no congenital abnormalities affecting the respiratory function or neonatal deaths. All patients were delivered by Caesarean section without labor between 24 and 38 gestational weeks. The amniotic fluid samples were analyzed immediately without centrifugation. A multiple logistic regression analysis was performed to explore the relationship between twin pregnancy and neonatal respiratory distress syndrome and transient tachypnea of the newborn (RDS/TTN).

RESULTS

The rate of RDS/TTN in infants was significantly higher and the lamellar body counts (LBCs) significantly lower in singleton pregnancies than that in twin pregnancies (P < .001). According to a multivariate logistic regression analysis, twin pregnancy (odds ratio, 0.34; 95% confidence interval, 0.22-0.55) was a significant preventive factor for neonatal RDS/TTN.

CONCLUSIONS

We showed that twin fetuses experience more rapid lung maturation and lung fluid absorption than singleton fetuses, as confirmed by the higher LBC values in twin fetuses.

The impact of fertility treatment on the neonatal respiratory outcomes and amniotic lamellar body counts in twin pregnancies

BACKGROUND

To elucidate the impact of fertility treatment on neonatal respiratory outcomes and amniotic lamellar body counts (LBCs) in twin pregnancies.

METHODS

One hundred ninety twin pairs, including 99 dichorionic twin (DCT) and 91 monochorionic twin (MCT) pairs were registered at our institutions. All amniotic fluid samples were obtained from each sac at cesarean section. Samples were analyzed immediately after arrival at the laboratory without centrifugation. We divided the patients into 3 groups: the no therapy group (natural conception), the induced ovulation group (with or without intrauterine insemination), and the assisted reproductive technology (ART) group (in vitro fertilization or intracytoplasmic sperm injection).

RESULTS

No statistically significant associations between the fertility treatment and the rates of neonatal RDS/TTN were observed in the whole study population (odds ratio [OR], 0.95; 95% confidence interval [CI], 0.45-2.00), DCT (OR, 0.86; 95%CI, 0.30-2.47), and MCT (OR, 1.45; 95%CI, 0.41-5.11). In addition, there was no association between the fertility treatment and neonatal RDS/TTN in the propensity score analysis of the whole study population (OR, 1.25; 95%CI, 0.57-2.74).

CONCLUSIONS

None of the individual types of fertility treatment had a direct impact on respiratory disorders such as RDS and TTN in twin infants.

Lower respiratory tract disorder hospitalizations among children born via elective early-term delivery

OBJECTIVE

We evaluated the hypothesis that elective early-term delivery increases the risk of childhood lower respiratory tract disorder hospitalization.

METHODS

Children born via early-term elective inductions were compared to full- or late-term elective inductions in a retrospective cohort study using Washington State birth certificate and hospital discharge data. Outcomes were the odds of lower respiratory disorder hospitalization before age five and cause specific odds ratios for asthma, bronchiolitis, bronchitis, and pneumonia. In addition, a subgroup analysis excluding infants with perinatal complications was conducted.

RESULTS

Electively induced early-term children were at significantly increased risk of hospitalization before age five for lower respiratory disorders compared to similar full- or late-term children (adjusted OR: 1.31, 95% CI: 1.11-1.55). Bronchiolitis was the only cause-specific outcome with a statistically significant increase in odds of hospitalization, though comparable increases were found for the less common diagnoses of asthma (adjusted OR: 1.39, 95% CI: 0.93-2.08) and pneumonia (adjusted OR: 1.27, 95% CI: 0.99-1.64). Excluding infants with perinatal complications did not alter the results.

CONCLUSIONS

There was an association between electively induced early-term delivery and hospitalization for lower respiratory tract disorders before age five. This reinforces policies discouraging elective early-term delivery.

Fetal proximal humeral epiphysis as an indicator of term gestation in different ethnic groups. J Matern Fetal Neonatal Med 2016;30:2505-2509. [PMID: 27819180 DOI: 10.1080/14767058.2016.1254184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

OBJECTIVES

Accurate pregnancy dating is critical for appropriate clinical management. Our aim was to determine the time of appearance of proximal humeral epiphysis (PHE), consistency of its appearance among ethnic groups and whether 3D imaging helps with its visualization.

METHODS

A cross-sectional study was done on 360 patients with 563 scans in different ethnic groups between August 2013 and July 2015. Inclusion criteria were singleton pregnancies (34-40+  weeks of gestation), well dated by <20 weeks sonogram.

RESULTS

PHE was not seen at 34 (n = 44) or 35 weeks (n = 36) and was present at gestational ages 36 (n = 3), 37 (n = 126), 38 (n = 96), 39 (n = 100) and 40 weeks (n = 28) in 2%, 12%, 51%, 75% and 100%, respectively. PHE was seen in 20 of 50 (60%) African-Americans, 22 of 61 (64%) south Asians, 41 of 72 (57%) Caucasians, 45 of 86 (48%) Hispanics and 41 of 80 (49%) Asians.

CONCLUSION

Appearance of PHE did increase with gestational age, prior to 40 weeks, it was not uniformly present and was seen as early as 36 weeks independent of ethnic group.

The transition from intra to extra-uterine life in late preterm infant: a single-center study

BACKGROUND

Infants born at 34 to 36 weeks of gestation (late preterm) are at greater risk for adverse outcomes than those born at 37 weeks of gestation or later. Aim of this paper is to examine risk factors for late preterm births and to investigate the complications of the transition period in late preterm infants (LPIs).

METHODS

All consecutive late preterm deliveries, excluded stillbirths, were included. Maternal and neonatal data, need for delivery room resuscitative procedures, temperature at birth (T1) and two hours after the admission (T2) were analyzed in all LPIs stratified by Gestational Age (GA) and divided into three groups (34, 35 and 36 weeks).

RESULTS

Two hundred seventy-six LPIs were analyzed. Pregnancy complications were present in 72 mothers (26.1 %), more frequently at 34 weeks of gestation respect to 35 and 36 weeks (p = 0.008, p = 0.006 respectively). Forty seven LPIs (17.1 %) needed for any resuscitation and 37 (13.4 %) were ventilated at birth. LPIs at 34 weeks were significantly more likely to receive ventilation respect to those at 35 and 36. At T1 the mean temperature resulted lower at 34 weeks respect to 36 weeks (p = 0.03). At T2 respect to T1, the rate of normothermic neonates increased at 35 and 36 weeks (p = 0.003, p = 0.005, respectively). Hypoglicemia rate was similar among the groups; 66.7 % of hypoglicemic neonates were hypothermic at T1. The rate of respiratory diseases and NICU admission decreased with increasing GA. Higher number of neonates ventilated at birth developed respiratory disorders respect to those unventilated (40.5 % vs 8.4 %; p < 0.001).

CONCLUSIONS

Transition period in LPIs may become critical, as resuscitation strategies can be required and heat loss can occur. LPIs, especially at 34 gestational weeks, are higher-risk group needing adequate and targeted management at birth.

Predicting neonatal respiratory morbidity by lamellar body count and gestational age

AIMS

To develop a predictive model for assessing the risk of developing neonatal respiratory morbidity using lamellar body counts (LBCs) and gestational age (GA) to provide a more patient-specific assessment.

METHODS

Retrospective cohort study of patients' ≥32 weeks' gestation who received amniocentesis with LBC analysis over a 9-year period. Respiratory morbidity was defined as respiratory distress syndrome, transient tachypnea of the newborn or oxygen requirement for >24 h. Logistic regression analyses were used to predict the absolute risk and odds of respiratory morbidity as a function of GA and lamellar body count.

RESULTS

Two hundred and sixty-seven mother-infant pairs included in the analysis with 32 cases (12.0%) of respiratory morbidity. When compared to those without respiratory morbidity, neonates with respiratory morbidity had amniocentesis performed at an earlier median GA, had lower mean birthweight and had lower median LBC (P<0.01). The GA specific absolute risks and odds ratios for the presence of respiratory morbidity were calculated. The predicted absolute risks of neonatal respiratory morbidity ranged from 38% at 32 weeks to 6% at 40 weeks when LBC were 35,000/μL.

CONCLUSION

GA specific predicted risk of neonatal respiratory morbidity using LBC provides a statistical model, which can aid clinicians in individually counseling patients regarding the absolute risk of their neonate developing respiratory morbidity.

The respiratory consequences of early-term birth and delivery by caesarean sections

In England and Wales, 19% of live births in 2012 were at 37-38 weeks' gestation, equating to nearly 140 000 early-term births each year. Since caesarean sections (CS) are often performed at early-term gestations, this accounts for some of the increased proportion of the early-term births. Infants born early-term are at an increased risk of neonatal respiratory morbidity particularly if they are delivered by caesarean section. The long term lung function data are limited but available data suggest that early-term delivery is associated with respiratory morbidity in childhood. CS also appears to be associated with increased neonatal morbidity and future development of respiratory symptoms. However, future studies need to confirm the independent effects of caesarean sections and early-term deliveries particularly for long term outcomes as both are likely to affect the respiratory system differently.

Electronic fetal monitoring patterns associated with respiratory morbidity in term neonates

OBJECTIVE

The purpose of this study was to identify electronic fetal monitoring patterns that are associated with neonatal respiratory morbidity.

STUDY DESIGN

In an on-going prospective cohort study of >8000 consecutive term, vertex, nonanomalous singleton pregnancies during labor, we performed this analysis within the first 5000 women as a representative sample. Electronic fetal monitoring patterns in the 30 minutes preceding delivery were extracted by trained obstetrics research nurses, who were blinded to clinical data, using the National Institute of Child Health and Human Development system; the data were compared between those with respiratory morbidity and healthy infants (no morbidities). The primary outcome was neonatal respiratory morbidity, which was defined as either oxygen requirement at ≥6 hours of life or any mechanical ventilation in the first 24 hours. Multivariable logistic regression was used to adjust for confounders.

RESULTS

Of 4736 neonates, 175 (3.4%) experienced respiratory morbidity. Most electronic fetal monitoring patterns were category II (96.6%; n = 4575). Baseline tachycardia (adjusted odds ratio [aOR], 2.9; 95% confidence interval [CI], 1.9-4.4), marked variability (aOR, 2.7; 95% CI, 1.5-5.0), and prolonged decelerations (aOR,2.7; 95% CI, 1.5-5.0) were significantly associated with an increased likelihood of term neonatal respiratory morbidity. Accelerations and persistent moderate variability were both significantly associated with a decreased likelihood of respiratory morbidity.

CONCLUSION

Specific features of category II electronic fetal monitoring patterns make respiratory morbidity more likely in nonanomalous term infants. Tachycardia, marked variability, or prolonged decelerations before delivery can assist providers in anticipating the potential need for neonatal respiratory support.

Systems biology evaluation of cell-free amniotic fluid transcriptome of term and preterm infants to detect fetal maturity

Background

Amniotic fluid (AF) is a proximal fluid to the fetus containing higher amounts of cell-free fetal RNA/DNA than maternal serum, thereby making it a promising source for identifying novel biomarkers that predict fetal development and organ maturation. Our aim was to compare AF transcriptomic profiles at different time points in pregnancy to demonstrate unique genetic signatures that would serve as potential biomarkers indicative of fetal maturation.

Methods

We isolated AF RNA from 16 women at different time points in pregnancy: 4 from 18 to 24 weeks, 6 from 34 to 36 weeks, and 6 from 39 to 40 weeks. RNA-sequencing was performed on cell-free RNA. Gene expression and splicing analyses were performed in conjunction with cell-type and pathway predictions.

Results

Sample-level analysis at different time points in pregnancy demonstrated a strong correlation with cell types found in the intrauterine environment and fetal respiratory, digestive and external barrier tissues of the fetus, using high-confidence cellular molecular markers. While some RNAs and splice variants were present throughout pregnancy, many transcripts were uniquely expressed at different time points in pregnancy and associated with distinct neonatal co-morbidities (respiratory distress and gavage feeding), indicating fetal immaturity.

Conclusion

The AF transcriptome exhibits unique cell/organ-selective expression patterns at different time points in pregnancy that can potentially identify fetal organ maturity and predict neonatal morbidity. Developing novel biomarkers indicative of the maturation of multiple organ systems can improve upon our current methods of fetal maturity testing which focus solely on the lung, and will better inform obstetrical decisions regarding delivery timing.

Electronic supplementary material

The online version of this article (doi:10.1186/s12920-015-0138-5) contains supplementary material, which is available to authorized users.

Chronic inflammation of the placenta: definition, classification, pathogenesis, and clinical significance

Chronic inflammatory lesions of the placenta are characterized by the infiltration of the organ by lymphocytes, plasma cells, and/or macrophages and may result from infections (viral, bacterial, parasitic) or be of immune origin (maternal anti-fetal rejection). The 3 major lesions are villitis (when the inflammatory process affects the villous tree), chronic chorioamnionitis (which affects the chorioamniotic membranes), and chronic deciduitis (which involves the decidua basalis). Maternal cellular infiltration is a common feature of the lesions. Villitis of unknown etiology (VUE) is a destructive villous inflammatory lesion that is characterized by the infiltration of maternal T cells (CD8+ cytotoxic T cells) into chorionic villi. Migration of maternal T cells into the villi is driven by the production of T-cell chemokines in the affected villi. Activation of macrophages in the villi has been implicated in the destruction of the villous architecture. VUE has been reported in association with preterm and term fetal growth restriction, preeclampsia, fetal death, and preterm labor. Infants whose placentas have VUE are at risk for death and abnormal neurodevelopmental outcome at the age of 2 years. Chronic chorioamnionitis is the most common lesion in late spontaneous preterm birth and is characterized by the infiltration of maternal CD8+ T cells into the chorioamniotic membranes. These cytotoxic T cells can induce trophoblast apoptosis and damage the fetal membranes. The lesion frequently is accompanied by VUE. Chronic deciduitis consists of the presence of lymphocytes or plasma cells in the basal plate of the placenta. This lesion is more common in pregnancies that result from egg donation and has been reported in a subset of patients with premature labor. Chronic placental inflammatory lesions can be due to maternal anti-fetal rejection, a process associated with the development of a novel form of fetal systemic inflammatory response. The syndrome is characterized by an elevation of the fetal plasma T-cell chemokine. The evidence that maternal anti-fetal rejection underlies the pathogenesis of many chronic inflammatory lesions of the placenta is reviewed. This article includes figures and histologic examples of all chronic inflammatory lesions of the placenta.

A point of care test for the determination of amniotic fluid interleukin-6 and the chemokine CXCL-10/IP-10

OBJECTIVE

Intra-amniotic inflammation is a mechanism of disease implicated in preterm labor, preterm prelabor rupture of membrane, cervical insufficiency, a short cervix, and idiopathic vaginal bleeding. Determination of interleukin (IL)-6 with immunoassays has been proven for more than two decades to be an excellent method for the detection of intra-amniotic inflammation. However, assessment of IL-6 for this indication has been based on immunoassays which are not clinically available, and this has been an obstacle for the implementation of this test in clinical practice. It is now possible to obtain results within 20 min with a point of care (POC) test which requires minimal laboratory support. This test is based on lateral flow-based immunoassay. The objective of this study was to compare amniotic fluid (AF) IL-6 and interferon-γ - inducible protein 10 (IP-10 or CXCL-10) concentrations determined using lateral flow-based immunoassay or POC test and standard enzyme-linked immunosorbent assay (ELISA) techniques.

MATERIAL AND METHODS

AF samples were collected from patients with singleton gestations and symptoms of preterm labor (n = 20). AF IL-6 and IP-10 concentrations were determined by lateral flow-based immunoassay and ELISA. Intra-amniotic inflammation was defined as AF IL-6 ≥ 2.6 ng/ml. AF IL-6 and IP-10 concentrations between two assays were compared.

RESULTS

(1) Lateral flow-based immunoassay POC AF IL-6 and IP-10 test results were strongly correlated with concentrations of this cytokine/chemokine determined by ELISA (Spearman's ρ = 0.92 and 0.83, respectively, both p < 0.0001); (2) AF IL-6 concentrations determined by the lateral flow-based immunoassay test were, on average, 30% lower than those determined by ELISA, and the median difference was statistically significant (p < 0.0001); and (3) in contrast, AF IP-10 concentrations determined by the lateral flow-based immunoassay test were, on average, only 7% lower than those determined by ELISA, and the median difference was not statistically significant (p = 0.81).

CONCLUSION

AF IL-6 and IP-10 concentrations determined using a lateral flow-based immunoassay POC are strongly correlated with concentrations determined by conventional ELISA. This justifies further studies about the diagnostic indices and predictive values of this POC test.

Risk score comprising maternal and obstetric factors to identify late preterm infants at risk for neonatal intensive care unit admission

AIM

The aim of this study was to develop and validate an antepartum risk score based on maternal and obstetric characteristics to predict the requirement for neonatal intensive care unit (NICU) admission among late preterm infants.

MATERIAL AND METHODS

A chart review was performed of 455 singleton late preterm deliveries at our institution between July 2010 and December 2011. Logistic regression analysis was used to develop a risk score, which was derived from β coefficients of the significant variables. A receiver-operator curve was plotted to determine the optimal cut-off score for predicting NICU admission. Validation of the score was tested in another cohort of 450 women who delivered a singleton late preterm infant between January 2012 and June 2013.

RESULTS

A total of 98 infants (21.5%) in the development cohort were admitted to the NICU. The significant factors for NICU admission included: premature rupture of membranes, antepartum hemorrhage, medical disorders during pregnancy, prenatal estimation of fetal weight, gestational age at delivery, and mode of delivery. These six variables were integrated into a risk-scoring model, which ranged from -2 to 9 points. A cut-off score of ≥1 produced the maximum area under the receiver-operator curve of 0.764. At this cut-off point, the sensitivity was 79.6% and specificity was 73.1%. When the risk score was tested in the validation cohort, similar results were demonstrated.

CONCLUSION

An antepartum risk score was developed to predict the requirement for NICU admission among late preterm infants and was validated in an independent cohort.

Late prematurity: a systematic review

OBJECTIVE

this study aimed to review the literature regarding late preterm births (34 weeks to 36 weeks and 6 days of gestation) in its several aspects.

SOURCES

the MEDLINE, LILACS, and Cochrane Library databases were searched, and the references of the articles retrieved were also used, with no limit of time.

DATA SYNTHESIS

numerous studies showed a recent increase in late preterm births. In all series, late preterm comprised the majority of preterm births. Studies including millions of births showed a strong association between late preterm birth and neonatal mortality. A higher mortality in childhood and among young adults was also observed. Many studies found an association with several neonatal complications, and also with long-term disorders and sequelae: breastfeeding problems, cerebral palsy, asthma in childhood, poor school performance, schizophrenia, and young adult diabetes. Some authors propose strategies to reduce late preterm birth, or to improve neonatal outcome: use of antenatal corticosteroids, changes in some of the guidelines for early delivery in high-risk pregnancies, and changes in neonatal care for this group.

CONCLUSIONS

numerous studies show greater mortality and morbidity in late preterm infants compared with term infants, in addition to long-term disorders. More recent studies evaluated strategies to improve the outcomes of these neonates. Further studies on these strategies are needed.

Fetal lung maturity testing: the end of an era

Respiratory distress syndrome is a major cause of neonatal morbidity and mortality that is most commonly caused by a deficiency in lung surfactant in premature infants. Therefore, laboratory tests were developed to measure the presence and/or concentration of lung surfactant in amniotic fluid in order to estimate maturity of the fetal lung. Although these tests were once widely employed, their utilization by physicians has decreased in recent years. Several studies have shown that demonstration of a mature fetal lung index by antenatal testing does not improve neonatal outcomes. Instead, decreased respiratory and nonrespiratory morbidities are most highly correlated with gestational age of the fetus. Therefore, fetal lung maturity testing may have passed the point of being clinically useful.

Neonatal morbidity occurs despite pulmonary maturity prior to 39 weeks gestation

OBJECTIVE

To compare outcomes among late-preterm or early-term neonates according to fetal lung maturity (FLM) status.

STUDY DESIGN

We conducted a retrospective cohort study of 234 eligible singletons delivered after FLM testing before 39 weeks gestation at our center over a 2-year time period. A primary composite neonatal outcome included death and major morbidities.

RESULT

The overall rate of primary composite morbidity was 25/46 (52.2%) and 61/188 (32.4%) in the immature/transitional and mature groups, respectively. After adjustment for confounders including gestational age, the composite outcome was not significantly different; adjusted odds ratio (aOR)=1.4 (confidence interval (CI)=0.7-3.0). The rate of respiratory distress syndrome was significantly higher in the immature/transitional group; odds ratio=3.4 (CI=1.1-10.3) as expected.

CONCLUSION

FLM status did not correlate with the spectrum of neonatal morbidities in late-preterm and early-term births. Neonatal complications remained common in both groups.

Validation of the joint commission exclusion criteria for elective early-term delivery

OBJECTIVE

To evaluate whether current Joint Commission (JC) exclusion criteria for measure PC-01, "Elective Delivery" before 39 weeks of gestation, accurately identify valid, codeable indications for planned early-term delivery.

METHODS

We performed a review and critical analysis of all cases recorded as noncompliant for the measure in a large health care system during the second half of 2012.

RESULTS

During the study period, of 107,145 total deliveries, 205 cases were reported as noncompliant with PC-01. Ten percent of compliance fallouts (ie, cases coded as noncompliant) resulted from valid indications for delivery identifiable by International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) coding not included on the JC exclusion list; these were primarily unusual or extreme variations of these conditions. Twenty-five percent of fallouts represented valid indications not represented by an ICD-9-CM code. Eight percent of cases were reported as fallouts as a result of imprecise physician charting; only 2% represented chart abstraction errors. Fifty-five percent of cases involved stated indications for early-term delivery not generally recognized as such by the medical community. Compliance rates of 98% are achievable across a large population using the current ICD-9-CM-based metric for compliance assessment used by the JC (PC-01). The current exclusion list does not appear to be amenable to further improvement by inclusion of more or different ICD-9-CM codes. However, given the low volumes generated using the current PC-01 denominator definition, approximately 60% of facilities would have compliance rates below a 95% benchmark with even a single justified outlier if analyzed on a quarterly basis.

CONCLUSION

Our data validate the current JC exclusion criteria for this measure, which identify the vast majority of valid indications for early-term delivery used by obstetrician-gynecologists and identifiable with ICD-9-CM codes.

LEVEL OF EVIDENCE

III.

Respiratory disorders in moderately preterm, late preterm, and early term infants

Even when it is just a few weeks before term gestation, early birth has consequences, resulting in higher morbidity and mortality. Respiratory issues related to moderate prematurity include delayed neonatal transition to air breathing, respiratory distress resulting from delayed fluid clearance (transient tachypnea of the newborn), surfactant deficiency (respiratory distress syndrome), and pulmonary hypertension. Management approaches emphasize appropriate respiratory support to facilitate respiratory transition and minimize iatrogenic injury. Studies are needed to determine the impact of respiratory distress coupled with mild-moderate prematurity on long-term outcome.

Epidemiology of moderate preterm, late preterm and early term delivery

Moderate preterm, late preterm, and early term deliveries represent a major and growing public health concern. These deliveries are associated with significant financial burden and pose serious risks to mothers and newborns. Women who deliver at moderate and late gestational ages in one pregnancy are at increased risk of delivering at these gestational ages, or earlier, in a subsequent pregnancy. Births in moderate preterm and late preterm gestational ages are associated with significant infant morbidity and mortality. Efforts to reduce deliveries in moderate preterm and late preterm gestations and interventions designed to ameliorate the problems in infants delivered at the gestational ages may be targets worthy of future investigation.

Physiologic underpinnings for clinical problems in moderately preterm and late preterm infants

This article highlights some of the important developmental characteristics that underpin common problems seen in moderate and late preterm infants. Preterm birth is associated with an increased prevalence of clinical problems caused by functional immaturities in a wide variety of organ systems, acquired problems, and problems associated with inadequate monitoring and/or follow-up plans. There are variations in the degree of maturation among infants of similar gestational ages because the developmental process is nonlinear. Therefore, different organ systems mature at rates and trajectories that are specific to their functions. A better understanding of these principles can help guide optimal treatment strategies.

Maternal and neonatal complications of elective early-term deliveries

Approximately 10% to 15% of all deliveries in the United States are performed before 39 completed weeks of gestation without a true medical indication for early delivery, despite long-standing recommendations against this practice. Early-term deliveries are those that occur between 3707 and 3867 weeks. It is now recognized that maternal and neonatal complications have increased for deliveries that occur at early- vs late-term gestation. The reasons for the increase in the rate of elective early-term deliveries are unclear but likely involve both patient and physician factors. Various strategies have been used to increase awareness of the morbidities associated with the practice of elective early-term delivery and to reduce its frequency. Insurers and quality accrediting agencies are increasingly holding hospitals accountable for their rates of elective early-term deliveries, and this pressure will likely continue to lead to widespread change in the practice of obstetrics. The interventions to increase adherence to evidence-based medicine guidelines that are described within this review may also be applicable to other areas of medicine.

Amniotic fluid: the use of high-dimensional biology to understand fetal well-being

Our aim was to review the use of high-dimensional biology techniques, specifically transcriptomics, proteomics, and metabolomics, in amniotic fluid to elucidate the mechanisms behind preterm birth or assessment of fetal development. We performed a comprehensive MEDLINE literature search on the use of transcriptomic, proteomic, and metabolomic technologies for amniotic fluid analysis. All abstracts were reviewed for pertinence to preterm birth or fetal maturation in human subjects. Nineteen articles qualified for inclusion. Most articles described the discovery of biomarker candidates, but few larger, multicenter replication or validation studies have been done. We conclude that the use of high-dimensional systems biology techniques to analyze amniotic fluid has significant potential to elucidate the mechanisms of preterm birth and fetal maturation. However, further multicenter collaborative efforts are needed to replicate and validate candidate biomarkers before they can become useful tools for clinical practice. Ideally, amniotic fluid biomarkers should be translated to a noninvasive test performed in maternal serum or urine.

Amniocentesis for fetal lung maturity: will it become obsolete?

AMNIOCENTESIS FOR FETAL LUNG MATURITY HAS HISTORICALLY BEEN PERFORMED FOR MANY REASONS: uterine and placental complications, maternal comorbidities, fetal issues, and even obstetric problems. Even though the risks associated with third trimester amniocentesis are extremely low, complications have been documented, including preterm labor, placental abruptions, intrauterine rupture, maternal sepsis, fetal heart rate abnormalities, and fetal-maternal hemorrhage. This review presents the types of tests for fetal lung maturity, presents the indications and tests utilized, and discusses recommendations for when amniocentesis for fetal lung maturity may be appropriate.

Increased neonatal morbidity despite pulmonary maturity for deliveries occurring before 39 weeks

OBJECTIVE

To compare neonatal outcomes following deliveries <39 weeks after confirmation of fetal lung maturity with scheduled deliveries ≥39 weeks.

METHODS

A retrospective cohort study examining neonatal outcomes of women who were delivered following documented fetal pulmonary maturity at 36, 37, and 38 weeks compared to women undergoing a scheduled delivery at 39, 40, and 41 weeks. The χ(2)-test and Student's t-test were used to compare categorical and continuous data, respectively.

RESULTS

Delivery prior to 39 weeks following fetal pulmonary maturity was associated with a 8.4% composite neonatal morbidity rate as compared to 3.3% for deliveries at 39 weeks or greater (relative risk [RR] 2.9; confidence interval [CI] 2.4-3.6). Neonatal respiratory morbidity was significantly higher (5.4%) for those delivering at less than 39 weeks with documented fetal pulmonary maturity as compared to 2.1% for those delivering at 39 weeks or greater (RR 3.0; CI 2.3-3.9). Increased neonatal morbidity persisted for those delivered prior to 39 weeks even after excluding all diabetics (p < 0.001). Significant increases in neonatal morbidity were noted for deliveries prior to 39 weeks regardless of the mode of delivery.

CONCLUSION

Despite fetal pulmonary maturity, delivery before 39 weeks is associated with significantly increased neonatal morbidity when compared to scheduled deliveries at 39 weeks or greater.

Neonatal respiratory morbidity in the early term delivery

OBJECTIVE

The purpose of this study was to evaluate the risk of respiratory morbidity in neonates delivered at "early term" (37-38 weeks) compared with those delivered at 39 weeks.

STUDY DESIGN

We conducted a retrospective cohort study of singleton deliveries from 37(0/7) to 39(6/7) weeks' gestation. Our primary outcome was composite respiratory morbidity.

RESULTS

Of 2273 deliveries at 37-39 weeks, 51% (n = 1169) delivered in the early term period. Infants delivered at 37-38 weeks had a 2-fold increased risk of respiratory distress syndrome, oxygen use, continuous positive airway pressure use, and composite respiratory morbidity (risk ratio [RR], 2.9; 95% confidence interval [CI], 1.0-7.9; oxygen usage RR, 2.0; 95% CI, 1.4-2.9; continuous positive airway pressure RR, 1.9; 95% CI, 1.1-3.2; composite respiratory morbidity RR, 2.0; 95% CI, 1.4-2.8).

CONCLUSION

The 2-fold increased risk of composite respiratory morbidity of infants in the early term period supports the urgency for limiting nonindicated deliveries to ≥ 39 weeks' gestation.

Should patients with documented fetal lung immaturity after 34 weeks of gestation be treated with steroids?

OBJECTIVE

The purpose of this study was to determine whether corticosteroid administration after 34 weeks of gestation is associated with improved neonatal outcome in the presence of fetal lung immaturity.

STUDY DESIGN

We conducted a retrospective cohort study of women who underwent amniocentesis to determine fetal lung maturity from 34-37 weeks of gestation. Patients with negative results (167 women) received steroids based on physician preference and were categorized into 2 groups: study group treated with betamethasone (n = 83 women) and control group in which patients did not receive betamethasone therapy (n = 84 women). The 2 groups were compared with respect to neonatal outcomes. Composite neonatal morbidity was defined as the presence of respiratory distress syndrome, transient tachypnea of the newborn infant, or the need for respiratory support.

RESULTS

The rate of composite neonatal morbidity was significantly lower among infants who were exposed to steroids compared with the control group (8.4% vs 21%; P = .02). Multiple regression analysis revealed that corticosteroid administration was associated independently with the composite morbidity outcome.

CONCLUSION

Antenatal steroid administration after 34 weeks of gestation is associated with improved neonatal outcome and should be considered when fetal lung immaturity is documented.

Antenatal steroids for treatment of fetal lung immaturity after 34 weeks of gestation: an evaluation of neonatal outcomes

OBJECTIVE

To estimate whether antenatal corticosteroids given after fetal lung immaturity in pregnancies at 34 weeks of gestation or more would improve neonatal outcomes and, in particular, respiratory outcomes.

METHODS

We compared outcomes of 362 neonates born at 34 weeks of gestation or more after fetal lung maturity testing: 102 with immature fetal lung indices were treated with antenatal corticosteroids followed by planned delivery within 1 week; 76 with immature fetal lung indices were managed expectantly; and 184 were delivered after mature amniocentesis. Primary outcomes were composites of neonatal and respiratory morbidity.

RESULTS

Compared with corticosteroid-exposed neonates those born after mature amniocentesis had lower rates of adverse neonatal (26.5% compared with 14.1%, adjusted odds ratio [OR] 0.51, 95% confidence interval [CI] 0.27-0.96) and adverse respiratory outcomes (9.8% compared with 3.3%, adjusted OR 0.33, 95% CI 0.11-0.98); newborns born after expectant management had significantly less respiratory morbidity (1.3% compared with 9.8%, adjusted OR 0.11, 95% CI 0.01-0.92) compared with corticosteroid-exposed newborns.

CONCLUSION

Administration of antenatal corticosteroids after immature fetal lung indices did not reduce respiratory morbidity in neonates born at 34 weeks of gestation or more. Our study supports prolonging gestation until delivery is otherwise indicated.

LEVEL OF EVIDENCE

II.

'The influence of gestational age and socioeconomic status on neonatal outcomes in late preterm and early term gestation: a population based study'

Background

Infants born late preterm (34 + 0 to 36 + 6 weeks GA (gestational age)) are known to have higher neonatal morbidity than term (37 + 0 to 41 + 6 weeks GA) infants. There is emerging evidence that these risks may not be homogenous within the term cohort and may be higher in early term (37 + 0 to 38 + 6 weeks GA). These risks may also be affected by socioeconomic status, a risk factor for preterm birth.

Methods

A retrospective population based cohort of infants born at 34 to 41 weeks of GA was assembled; individual and area-level income was used to develop three socioeconomic (SES) groups. Neonatal morbidity was grouped into respiratory distress syndrome (RDS), other respiratory disorders, other complications of prematurity, admission to a Level II/III nursery and receipt of phototherapy. Regression models were constructed to examine the relationship of GA and SES to neonatal morbidity while controlling for other perinatal variables.

Results

The cohort contained 25 312 infants of whom 6.1% (n = 1524) were born preterm and 32.4% (n = 8203) were of low SES. Using 39/40 weeks GA as the reference group there was a decrease in neonatal morbidity at each week of gestation. The odds ratios remained significantly higher at 37 weeks for RDS or other respiratory disorders, and at 38 weeks for all other outcomes. SES had an independent effect, increasing morbidity with odds ratios ranging from 1.2–1.5 for all outcomes except for the RDS group, where it was not significant.

Conclusions

The risks of morbidity fell throughout late preterm and early term gestation for both respiratory and non-respiratory morbidity. Low SES was associated with an independent increased risk. Recognition that the morbidities associated with prematurity continue into early term gestation and are further compounded by SES is important to develop strategies for improving care of early term infants, avoiding iatrogenic complications and prioritizing public health interventions.

Oversight of elective early term deliveries: avoiding unintended consequences

The national movement to eliminate elective delivery at <39 weeks' gestation has engendered much enthusiasm and is a major step forward in the evolution of perinatal patient safety. Our experience with >1 million births in the past 5 years suggests the existence of a number of potential pitfalls that should be considered in policy development, enforcement, and compliance monitoring. Attention to these details will ensure continued patient benefit from these policies without endangering those fetuses in whom early term delivery is warranted medically.