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At least 19 recordsLinked to original sources
PubMed2000

Endotracheal intubation at birth for preventing morbidity and mortality in vigorous, meconium-stained infants born at term.

BACKGROUND: On the basis of evidence from non-randomised studies, it has been recommended that all babies born through thick meconium should have their tracheas intubated so that suctioning of their airways can be performed. The aim is to reduce the incidence and severity of meconium aspiration syndrome. However, for term babies who are vigorous at birth endotracheal intubation may be both difficult and unnecessary. OBJECTIVES: To determine if endotracheal intubation and suction of the airways at birth in vigorous term meconium-stained babies is more beneficial than routine resuscitation including aspiration of the oro-pharynx. SEARCH STRATEGY: The search was made from Oxford Database of Perinatal Trials, the Neonatal Trials Registry of the Cochrane Neonatal Collaborative Review Group and information obtained from knowledgeable practising neonatologists. SELECTION CRITERIA: Randomised trials which compared a policy of routine vs no (or selective) use of endotracheal intubation and aspiration in the immediate management of vigorous term meconium-stained babies at birth. DATA COLLECTION AND ANALYSIS: Data regarding clinical outcomes including mortality, meconium aspiration syndrome, other respiratory conditions, pneumothorax, need for oxygen supplementation, stridor, convulsions and hypoxic-ischaemic encephalopathy were abstracted and analysed using Revman 3.1.1. MAIN RESULTS: Four randomised controlled trials of endotracheal intubation at birth in vigorous term meconium-stained babies were identified. Meta-analysis of these trials does not support routine use of endotracheal intubation at birth in vigorous meconium-stained babies to reduce mortality, meconium aspiration syndrome, other respiratory symptoms or disorders, pneumothorax, oxygen need, stridor, HIE and convulsions. REVIEWER'S CONCLUSIONS: Routine endotracheal intubation at birth in vigorous term meconium-stained babies has not been shown to be superior to routine resuscitation including oro-pharyngeal suction. This procedure cannot be recommended for vigorous infants until more research is available.

Humans↗
PubMed2000

Amnioinfusion for meconium-stained liquor in labour.

BACKGROUND: Amnioinfusion aims to prevent or relieve umbilical cord compression during labour by infusing a solution into the uterine cavity. It is also thought to dilute meconium when present in the amniotic fluid and so reduce the risk of meconium aspiration. However it may be that the mechanism of effect is that it corrects oligohydramnios (reduced amniotic fluid), for which thick meconium staining is a marker. OBJECTIVES: The objective of this review was to assess the effects of amnioinfusion for meconium-stained liquor on perinatal outcome. SEARCH STRATEGY: The Cochrane Pregnancy and Childbirth Group trials register and the Cochrane Controlled Trials Register were searched. SELECTION CRITERIA: Randomised trials comparing amnioinfusion with no amnioinfusion for women in labour with moderate or thick meconium-staining of the amniotic fluid. DATA COLLECTION AND ANALYSIS: Eligibility and trial quality were assessed by one reviewer. MAIN RESULTS: Ten studies, most involving small numbers of participants, were included. Under standard perinatal surveillance, amnioinfusion was associated with a reduction in the following: heavy meconium staining of the liquor (relative risk 0.03, 95% confidence interval 0.01 to 0.15); variable fetal heart rate deceleration (relative risk 0.47, 95% confidence interval 0.24 to 0. 90); and a trend to reduced caesarean section overall (relative risk 0.83, 95% confidence interval 0.69 to 1.00). No perinatal deaths were reported. Under limited perinatal surveillance, amnioinfusion was associated with a reduction in the following: meconium aspiration syndrome (relative risk 0.24, 95% confidence interval 0. 12 to 0.48); neonatal hypoxic ischaemic encephalopathy (relative risk 0.07, 95% confidence interval 0.01 to 0.56) and neonatal ventilation or intensive care unit admission (relative risk 0.56, 95% confidence interval 0.39 to 0.79); there was a trend towards reduced perinatal mortality (relative risk 0.34, 95% confidence interval 0.11 to 1.06). REVIEWER'S CONCLUSIONS: Amnioinfusion is associated with improvements in perinatal outcome, particularly in settings where facilities for perinatal surveillance are limited. The trials reviewed are too small to address the possibility of rare but serious maternal adverse effects of amnioinfusion.

Amnion↗
PubMed2003

Racial disparity in meconium-stained amniotic fluid and meconium aspiration syndrome in the United States, 1989-2000.

OBJECTIVE: To estimate the prevalence of meconium-stained amniotic fluid and meconium aspiration syndrome, as well as the differences in case fatality from meconium aspiration syndrome, between non-Hispanic black and non-Hispanic white infants. METHODS: We studied non-Hispanic black and non-Hispanic white live births with weights greater than 2.5 kg and gestational ages greater than 35 weeks, using the linked US birth and infant death cohorts for three periods: 1989-1991, 1995-1997, and 1998-2000. We used logistic regression to estimate the risks of meconium-stained amniotic fluid and meconium aspiration syndrome and to estimate the case fatality of meconium aspiration syndrome by maternal race, birth weight, period, and pregnancy complications. RESULTS: Risk of meconium-stained amniotic fluid was 80% higher in non-Hispanic blacks when compared with non-Hispanic whites (birth weight-adjusted odds ratio [OR], 1.81, 95% confidence interval [CI] 1.80, 1.82). The prevalence of pregnancy complications did not explain this racial disparity. Risk of meconium aspiration syndrome in non-Hispanic blacks was 67% higher when compared with non-Hispanic whites (birth weight-adjusted OR 1.67, 95% CI 1.64, 1.70). The case fatality rate of meconium aspiration syndrome was similar between non-Hispanic blacks and non-Hispanic whites in the three periods, with rates of 15.5, 15.2, and 11.2 per 1000 in non-Hispanic blacks and 13.5, 11.2, and 10.1 per 1000 in non-Hispanic whites in 1989-1991, 1995-1997, and 1998-2000, respectively. CONCLUSION: Our results suggest that when compared with non-Hispanic whites, non-Hispanic blacks are at significantly greater risk for meconium-stained amniotic fluid and meconium aspiration syndrome but not for meconium aspiration syndrome case fatality.

Amniotic Fluid↗
PubMed1996

The surface and transport properties of meconium and reconstituted meconium solutions.

Passage of meconium in utero and subsequent pulmonary aspiration of meconium admixed with amniotic fluid is a major cause of neonatal respiratory distress. Airway clearance is the first defense of the lung, and clearance is dependent on the bulk physical (rheologic) as well as the surface properties of airway material. We therefore evaluated the surface adhesive properties and the transport properties of freshly passed meconium and of two dilutions of reconstituted, blended, meconium as used to mimic the effect of meconium passage into the amniotic fluid in animal models of meconium aspiration syndrome. Reconstituted and fresh meconium had similar physical and transport properties, including an extremely high interfacial (adhesion) tension and very poor transportability by either airflow or cilia. The similarities between the freshly passed and reconstituted meconium suggest that the latter is an adequate substitute for use in animal models of meconium aspiration syndrome. The high adhesiveness of meconium suggests a potential role for surfactant administration as an adhesive to improve airway clearance after meconium aspiration.

Adhesives↗
PubMed1999

Meconium stimulates a pro-inflammatory response in peritoneal macrophages: implications for meconium peritonitis.

BACKGROUND/PURPOSE: Although meconium peritonitis is a rare condition, the mortality rate can be as high as 40%. Meconium peritonitis is a result of intestinal perforation in utero, which leads to dense inflammation in the peritoneal cavity. The fetus has relatively immature peritoneal defense mechanisms, so the cause of this dense inflammation is unclear. The peritoneal macrophage is a key cell in the peritoneal inflammatory response in adults. The purpose of this investigation was to determine if sterile meconium had a direct stimulatory effect on the peritoneal macrophage. METHODS: Peritoneal macrophages were harvested from adult C3H/HEN mice. The cells were placed in microtiter wells at 10(5) cells per well. Sterile human meconium was diluted in media and placed in the wells at varying concentrations for 8 hours. Lipopolysaccharide (LPS) (10 microg/mL) served as a positive control. Supernatants were harvested and assayed for tumor necrosis factor alpha (TNF-alpha) using a commercial ELISA kit. Separate cells were assayed for TNF-alpha message using polymerase chain reaction (PCR). In another series of experiments, procoagulant activity (PCA) was determined on freeze-thawed cells using a two-stage amidolytic assay. To test for the role of protein kinase C (PKC) in the PCA response H7, a PKC inhibitor, was used as well. RESULTS: Meconium stimulation resulted in a significant increase in TNF-alpha compared with negative controls with a peak at 0.1% meconium (121 pg/mL v 11 pg/mL, P<.05). There was a significant increase in PCA, with a 10-fold increase with 1% meconium compared with controls (P<.05). This response was limited to less than 5% by PKC inhibition. CONCLUSIONS: Sterile meconium results in a marked proinflammatory response in the peritoneal macrophage with elevations of both PCA and TNF-alpha. The TNF response is likely mediated at a pretranscriptional level because there is a marked increase in TNF mRNA. These data suggest that the PCA response is regulated by a PKC mechanism similar to LPS. Stimulation of the peritoneal macrophage by meconium is a possible cause of the marked inflammation seen in meconium peritonitis.

Animals↗
PubMed2000

Fetal erythropoietin levels in pregnancies complicated by meconium passage: does meconium suggest fetal hypoxia?

OBJECTIVE: We sought to determine whether umbilical cord plasma erythropoietin levels were different in deliveries complicated by meconium passage and to determine whether this response is influenced by gestational age. STUDY DESIGN: Fetal erythropoietin levels were measured in 203 appropriately grown neonates at 37 to 43 weeks of gestation; among those, 70 had passed meconium. RESULTS: Meconium passage in the entire population was associated with elevated fetal erythropoietin levels (68 vs 31 mIU/mL; P <.001). Cord blood gases, pH, base deficit, and PO (2), as well as the 1- and 5-minute Apgar scores, were not different between the meconium and no-meconium groups. Gestational age and birth weights were significantly higher in the meconium group. Stepwise multiple regression analysis with meconium and gestational age used as the independent variables showed both meconium and gestational age to be independently associated with fetal erythropoietin levels (r = 0.356, F = 14.5; meconium, P <.001; gestational age, P <.01). CONCLUSIONS: These results suggest that meconium passage can be associated with chronic fetal hypoxia as demonstrated by elevated fetal erythropoietin levels, independent of gestational age.

Apgar Score↗
PubMed2002

Albumin mixed with meconium attenuates pulmonary dysfunction in a newborn piglet model with meconium aspiration.

We hypothesized that lipids and bile acids in meconium may induce pulmonary insufficiency in newborns. Because albumin may bind these components we studied the effect of albumin on meconium-induced lung injury in piglets. We measured concentration of FFA in the meconium (110 mg dry weight/mL) and added albumin to provide a molar FFA to albumin ratio of 1:1. Newborn piglets, 0-2 d of age, artificially ventilated and exposed to hypoxemia by ventilation with 8% O2, were randomized to group A receiving meconium (n = 12) or group B receiving meconium + albumin (n = 12), 3 mL/kg intratracheally. The animals were reoxygenated for 8 h. Reoxygenation was started when mean blood pressure was <20 mm Hg or base excess was <-20 mM. Pulmonary function was assessed in parallel with pulmonary hemodynamics. From the start of reoxygenation and the next 8 h we found a significant difference (by ANOVA) between the two groups in oxygenation index (p = 0.005), with an increase from 1.6 +/- 0.2 to 6.1 +/- 6.8 (p = 0.04) in the meconium group and from 1.8 +/- 0.3 to 3.1 +/- 3.1 (NS) in meconium + albumin group. There were also significant differences (by ANOVA) between the groups in favor of the treatment group concerning need of inspired fraction of O2, mean airway pressure, dynamic compliance of the respiratory system, time constant, ventilation index, and pulmonary vascular resistance. In conclusion, albumin given concurrently with meconium significantly reduced detrimental effects of meconium aspiration in the lungs of newborn piglets.

Albumins↗
PubMed2000

Chemotactic activity for polymorphonuclear leukocytes: meconium versus meconium-stained amniotic fluid.

PROBLEM: Our previous study indicated that meconium-stained amniotic fluid (turbid AF) possessed a potent chemotactic activity for leukocytes, which may be dependent on interleukin-8. It is not known, however, whether meconium itself possesses this chemotactic activity. METHOD OF STUDY: Meconium samples were collected from mature neonates with and without turbid AF. A 5% meconium suspension in phosphate buffered saline was prepared and measured for its chemotactic activity for leukocytes using the blind well chamber technique. Concentrations of IL-8, TNFalpha and IL-1beta were also measured with ELISA. RESULTS: The number of leukocytes that migrated to the meconium suspension (35 +/- 27) was comparable with that of the clear AF (31 +/- 37), but was significantly lower than that of the turbid AF (184 +/- 62, P < 0.0001). The meconium suspension contained much lower levels of IL-8, TNFalpha and IL-1beta than the turbid AF. CONCLUSIONS: Meconium itself exhibits a lower chemotactic activity for polymorphonuclear leukocytes than turbid AF in vitro. The leukocyte chemotactic activity of turbid AF does not originate from meconium itself.

Amniotic Fluid↗
PubMed2003

[Management of meconium peritonitis: a remarkable case of idiopathic meconium peritonitis diagnosed antenatally].

Meconium peritonitis is an inflammatory peritonitis induced by meconium extruding into the peritoneal cavity through a perforation of the fetal intestine. Antenatal diagnosis is possible. Prognosis depends on the pathology having caused perforation. This is often unknown. The objectives of this article are to analyze the contribution of antenatal investigations to estimating neonatal prognosis of meconium peritonitis, and to define optimal management. We describe a case of meconium peritonitis diagnosed in utero with particularly severe ultrasound presentation suggesting a potentially lethal course for the neonate. An eutrophic infant was delivered vaginally after preliminary aspiration of the meconium ascites. The neonate presented with a very distended abdomen and responded well to neonatal resuscitation. Laparotomy exploration confirmed the diagnosis of meconium peritonitis. No cause was identified. No obvious perforation was found. The postsurgery period was uneventful. At later follow-up the infant was doing well, free of further problems notably of any digestive disorder. Antenatal ultrasound features suggestive of severe meconium peritonitis are distended fetal bowel loops, huge cystic masses, major meconium ascites, and polyhydramnios. These neonates have a high risk of obstruction and intestinal perforation. Intestinal resection is frequently required. Cardiopulmonary resuscitation is necessary more often in these neonates with a higher risk of fatal outcome due to respiratory distress syndrome or surgery complications. Prognosis remains good after antenatal diagnosis for neonates free of cystic fibrosis, providing delivery takes place in a center with adequate technical facilities.

Adult↗
PubMed2001

Variables associated with meconium aspiration syndrome in labors with thick meconium.

OBJECTIVE: To examine the possible maternal and fetal variables associated with meconium aspiration syndrome in labors with thick meconium. STUDY DESIGN: The fetal heart rate tracings, cord pH, Apgar scores and maternal risk factors were evaluated in singleton pregnancies with vertex presentation and thick meconium in labor. The study included 33 consecutive fetuses which developed a moderate or severe meconium aspiration syndrome and 104 consecutive fetuses which had a favorable outcome. RESULTS: Significant differences between fetuses with meconium aspiration syndrome and healthy fetuses were found in the following parameters: baseline FHR (154+/-17 vs. 136+/-10, P<0.0001), small accelerations/30 min (1.47+/-1.52 vs. 3.04+/-1.2, P<0.0001), large accelerations/30 min (1.46+/-1.96 vs. 3.5+/-2.31, P<0.0003), decelerations/30 min (4.9+/-3.9 vs. 2.4+/-2.1, P<0.0034), number of fetuses with reduced beat-to-beat variability (9/33 vs. 0/104, P<0.0001), cord pH (7.21+/-0.09 vs. 7.33+/-0.08, P<0.0013) and Apgar scores at 1 min (5+/-2 vs. 8+/-1, P<0.0001) and Apgar scores at 5 min (8+/-2 vs. 9.7+/-0.6, P<0.0001). Maternal risk factors were found in two of 33 sick infants and in 13 of 104 healthy infants. CONCLUSION: Thick meconium by itself is not associated with adverse fetal outcome. However, the incidence of meconium aspiration syndrome increases in cases of a non-reassuring FHR.

Apgar Score↗
PubMedDate not supplied

Chronic intrauterine meconium aspiration causes fetal lung infarcts, lung rupture, and meconium embolism.

Three neonates with chronic intrauterine meconium aspiration are reported. All had distinctive subpleural plate-infarcts of the lungs caused by meconium-induced vasoconstriction of peripheral preacinar arteries. These vessels showed plexogenic arteriopathy with medionecrosis and obliterative hyaline sclerosis. Organized thrombi and systemic-pulmonary arterial anastomoses were numerous. The infarcts contained inspissated meconium with a granulomatous reaction. In one case, lung rupture occurred, causing meconiumthorax and meconium embolism to hilar lymphatics and lymph nodes; this suggests that particulate meconium may enter the circulation. This fetus had rubella and probable acute twin-twin transfusion following the intrauterine death of the co-twin. The cause of the hypoxia that led to intrauterine passage of meconium in the other cases is unknown. Meconium-stained amniotic fluid was noted in only one case.

Chronic Disease↗
PubMed2001

Risk factors for meconium aspiration syndrome in infants born through thick meconium.

OBJECTIVE: To determine risk factors for meconium aspiration syndrome (MAS). METHOD: A cohort study was conducted of 70 consecutive singleton pregnancies complicated with thick meconium-stained amniotic fluid delivered at > or = 37 weeks' gestation. Cases were randomized either for elective abdominal delivery or spontaneous vaginal delivery after 20 min of external fetal heart rate (FHR) monitoring. Risk estimation analysis for MAS was performed calculating relative risks (RR) and odds ratios (OR). RESULTS: The presence of meconium below the vocal cords (RR=7.3, 95% CI=2.6-20.3), non-reassuring FHR tracings (RR=3.0, 95% CI=1.2-7.5), Apgar score < or = 6 at 5 min (RR=3.8, 95% CI=1.7-8.4) and an umbilical cord plasma erythropoietin (UCPer) level > 50 mlU/ml (RR=5.0, 95% CI=2.1-12.0) were found to be significant risk factors for MAS. The presence of meconium below the vocal cords (OR=33.4, 95% CI=3.6-303.7) and non-reassuring FHR tracings (OR=12.2, 95% CI=1.3-111.7) remained as significant risk factors at the end of the multivariate analysis. CONCLUSION: Non-reassuring FHR tracings and the presence of meconium below vocal cords are associated with an increased risk for MAS in infants born through thick meconium.

Adult↗
PubMed1988

Delivery room management of meconium staining of the amniotic fluid and the development of meconium aspiration syndrome.

A 1-year prospective survey of obstetric and pediatric management of meconium staining of the amniotic fluid in 464 patients was undertaken. Pharyngeal suctioning before delivery was performed using bulb syringe (N = 130), De Lee suction catheter (N = 186), or both (N = 98); endotracheal intubation after delivery was also done in 413 instances. Using any of the three suctioning techniques, no differences were seen in Apgar scores, respiratory rates, presence or absence of meconium on or below the vocal cords, or development of meconium aspiration syndrome (MAS). If meconium was present on the vocal cords, it was present below the vocal cords in 76% of the cases. If no meconium was visualized, it was found below the vocal cords in only 7% of the cases. Of the 142 infants with meconium below the vocal cords, 10% developed MAS and all 14 survived.

Amniotic Fluid↗
PubMed1992

Meconium peritonitis: extrusion of meconium and different sonographical appearances in relation to the stage of the disease.

By chance, we had the opportunity to make serial sonographic observations of the extrusion of meconium in a case of meconium peritonitis. Inflammation leads to exudative processes and production of fluid (ascites) in the fetal abdomen. Sonography at that stage of the disease may lead to a misdiagnosis such as 'fetal ascites' or 'non-immune hydrops'. After bowel perforation and extrusion of meconium, the latter appears as a solitary mass inside fetal ascites or as disseminated echogenic masses distributed subdiaphragmatically or perihepatically. Within a couple of days, in most cases the echogenicity of the masses increases. Calcifications lead to distinct shadowing. These calcifications are often the only visible signs of a previous meconium peritonitis. Serial sonograms are essential for the management of pregnancies with meconium peritonitis. If the amount of fetal ascites does not increase and no signs of cardiovascular stagnation appear, no invasive intrauterine diagnostic and therapeutic steps are required. In none out of the nine cases was a cause found.

Adult↗
PubMed1975

Studies in meconium: disaccharidase activities in meconium from cystic fibrosis patients and controls.

Meconium ileus represents the earliest clinical manifestation of cystic fibrosis. The differences found in the composition and amount of protein, mucoprotein, mucopolysaccharides, and reducing sugars in meconium from newborns with cystic fibrosis might be of significance relative to the pathogenesis and early diagnosis of this disease. We studied the enzymatic activity of disaccharidases (lactase, sucrase, maltase, and palatinase) in meconium of infants with cystic fibrosis and controls. We found an increase in the specific activity of these enzymes in the meconium from infants with cystic fibrosis as compared to the specific activity in meconium from normal infants. The increase in the activities, expressed as micromols per gram of protein per minute was: lactase, 100 times higher; sucrase, 18 times; maltase, 4.8 times, and palatinase, 8.9 times.

Cystic Fibrosis↗