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Query: UNIPROT:P01178 (oxytocin)
 15,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The respiratory distress syndrome is believed to be due to insufficient surfactant. It is known that there is a greater incidence of the respiratory distress syndrome among infants delivered by cesarean section before labor than among those delivered after labor at the same gestational age. The purpose of this study was to determine the effect of labor on the production of pulmonary surfactant. We measured the phospholipid content of lung lavage in newborn rabbits delivered by cesarean section before labor at 29, 30, and 31 (full-term) days gestation and after oxytocin-induced labor at 31 days. We also measured the activities of pulmonary cholinephosphate cytidylyltransferase and choline-phosphotransferase, enzymes involved in the de novo synthesis of phosphatidylcholine, the major component of surfactant. There was a two- to fourfold increase in the amount of lung lavage phospholipid during the first 6 h after birth. This was not dependent upon gestational age at delivery. There was a further two- to fourfold increase in the next 18 h which was, however, dependent upon gestational age. Labor increased the amount of lavage phospholipid from rabbits delivered at full term by 132%, 177%, and 50% at 3, 6, and 24 h after birth, respectively. There was a postnatal increase in the activity of cholinephosphate cytidylyltransferase. This was almost linear with time during the first 12 h, by which time essentially adult values were attained. Choline-phosphate cytidylyltransferase was not affected by labor. There was also a postnatal increase in the activity of cholinephosphotransferase but this was stimulated 86%, 59%, and 21% by labor at 0, 1, and 24 h after birth, respectively. These studies suggest that labor stimulates both the synthesis and secretion of surfactant in the immediate postnatal period and thus may be an important factor in the prevention of the respiratory distress syndrome of the newborn.
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PMID:Stimulation of surfactant production by oxytocin-induced labor in the rabbit. 19 22

To ensure an optimum result in pregnancy it is essential that the physician be alert in the antenatal period to recognize those women and their babies who are at risk during labour. Premature labour, with its attendant risk of respiratory distress syndrome in the newborn, continues to be an important factor in perinatal morbidity and mortality. Early recognition of predisposing factors and the judicious use of myometrial inhibiting agents have helped to reduce the incidence of fetal prematurity in these cases. A long interval between rupture of the membranes and delivery continues to be a danger to both mother and fetus. Delivery is recommended when gestation is beyond 36 weeks or when there are signs of incipient infection, and once labour has begun antibiotics should be used prophylactically. Failure of labour to progress should be recognized and managed aggressively in its early stages. Amniotomy and oxytocin infusion have reduced considerably the incidence of prolonged labour and its risks to both mother and fetus. The role of intrapartum monitoring of the fetal heart rate, measurement of the pH in the fetus's scalp blood and assessment of amniotic fluid is discussed, as is the monitoring of maternal well-being.
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PMID:Labour: when to worry. 63 Apr 88

A prospective investigation of 114 pregnant women compared 54 with consistently negative oxytocin challenge tests to 60 women who did not have oxytocin challenge tests but did have fetal monitoring during labor. Despite more high risk factors in the OCT group, there were no significant differences noted in the offspring. Specifically, extensive behavioral testing during the first 12 hours of life and at 3 days of age did not show any abnormalities. Furthermore, jaundice and respiratory distress were not seen more often after oxytocin exposure. These data argue that the OCT itself is without demonstrable adverse effects on the otherwise healthy fetus.
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PMID:Clinical and neurobehavioral effects of repeated intrauterine exposure to oxytocin: a prospective study. 70 69

While the modern approach to management of diabetic pregnancy has reduced the perinatal mortality significantly, the neonatal morbidity remains high. This study has investigated factors which may account for the persisting high neonatal morbidity when birth trauma has been virtually eliminated and the incidence of respiratory distress syndrome (RDS) considerably reduced. Major congenital malformations emerge not only as the leading cause of perinatal losses but also as an important cause of morbidity. Delivery before 37 weeks increased the incidence of RDS and hypocalcemia, and it is suggested that, when strict metabolic control is used and with the help of facilities to monitor the fetus closely in the last weeks of pregnancy, the number of infants delivered at this early date can be further reduced. The present study also indicates that normoglycemia should also be encouraged on the day of delivery as maternal hyperglycemia at this stage increases the incidence of neonatal hypoglycemia. Jaundice, which very commonly affects newborn infants of diabetic mothers, is influenced by the use of oxytocin for vaginal delivery and by infant overweight (greater than 90th percentile) at birth, factors which are not beyond control. Finally, route of delivery per se may not be important in relation to neonatal morbidity.
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PMID:Neonatal morbidity among infants of diabetic mothers. 72 47

From 1985 to 1988 we analyzed two hundred puerperas with term pregnancies and live newborns which pregnancy ended by vaginal route. One hundred of them received oxytocin during the labor and one hundred didn't receive it. The results showed that the use of oxytocin produces and increase in the cervical and vaginal tears; the Apgar score of the newborns was lower with a longer period in the incubator, and a high rate of complications regarding to respiratory distress and jaundice. These results were statistically significant according ti Chi square test with p less than 0.05.
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PMID:[Oxytocin. Use and abuse]. 186 Jun 78

Although there is no doubt that antepartum corticosteroid treatment is effective in reducing the incidence of respiratory distress syndrome (RDS), the potential benefits cannot be fully realised for several reasons. Many patients deliver within 24 hours of the start of treatment because tocolytic treatment is withheld or ineffective. In other patients, contraindications to delayed delivery may exist. In addition, corticosteroids are relatively ineffective in the group of infants at greatest risk (less than 28 weeks). Marked improvements in benefit will be achieved by improved tocolytics (perhaps indomethacin and/or oxytocin analogues), by more precise methods of predicting and diagnosing preterm labour, and by methods that enhance the response to corticosteroids at very early gestational ages. In regard to the latter, there is encouragement from experimental work showing synergism of antepartum steroids with simultaneous TRH treatment and with neonatal instillation of surfactant.
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PMID:Can the benefits of antepartum corticosteroid treatment be improved? 268 Jun 75

Synthetic glucocorticoids have become an important clinical tool with which to advance fetal lung maturation in women at risk of early preterm birth, and this has succeeded in reducing neonatal mortality and morbidity from respiratory distress syndrome. Although previous studies have shown that glucocorticoids have deleterious consequences on fetal development, there is little information regarding the effects of clinically relevant repeated maternal doses of glucocorticoids on fetal growth and hypothalamic-pituitary-adrenal (HPA) function. We hypothesised that repeated prenatal exposure to increased concentrations of glucocorticoids would alter fetal growth and HPA axis development. Pregnant ewes were injected with betamethasone (0.5 mg/kg) or vehicle at 104, 111 and 118 days of gestation (term 150 days). Animals were sacrificed at 125 and 146 days of gestation, at which time fetal weights were recorded. Maternal and fetal blood samples were gathered and fetal tissue collected. Maternal oestradiol concentrations were significantly greater than those in controls at 125 days of gestation, but were not different at 146 days. Maternal plasma progesterone concentrations were similar between groups at both 125 and 146 days of gestation. Weight at birth was significantly reduced by 23% at 125 days and 19% at 146 days of gestation (P<0.05) after exposure to glucocorticoid. Cord plasma ACTH concentrations were not significantly different between groups at day 125, but were significantly increased in day 146 fetuses of ewes that had received betamethasone (P<0.05). Cord plasma cortisol concentrations followed the same trend, although differences were not statistically significant. Cord plasma corticosteroid binding capacity (CBC) was significantly increased at 125 days of gestation in fetuses of betamethasone-treated animals (P<0.05), but not at 146 days of gestation. To examine the mechanisms regulating the increase in cord plasma ACTH of 146-day fetuses, we used in situ hybridisation to determine the distribution and levels of mRNA encoding key pituitary and hypothalamic neuropeptides of the HPA axis. In pituitaries of 146-day fetuses, there were no significant differences in the regional pattern of distribution or amounts of pro-opiomelanocortin (POMC) mRNA between betamethasone-treated animals and controls, in either the pars intermedia or the inferior and superior regions of the pars distalis. Neither prohormone convertase (PC)-1 nor PC-2 mRNA levels in pituitaries of 146-day fetuses were significantly different between treatment groups. After maternal betamethasone, immunoreactive ACTH peptide content in the fetal pars distalis was not different but glucocorticoid receptor (GR) mRNA levels in the pars distalis were increased significantly (P<0.05). No significant difference in distribution pattern or concentrations of corticotrophin-releasing hormone (CRH) mRNA, GR mRNA, oxytocin mRNA and pre-proenkephalin mRNA were found in hypothalami from fetuses at 146 days of gestation after betamethasone treatment. We conclude that antenatal betamethasone given to pregnant sheep in a manner similar to that used in human obstetric practice results in reduced weight at birth at 125 and 146 days, and altered basal cord levels of plasma ACTH and corticosteroid binding capacity, but these changes are not reflective of changes in steady state concentrations of POMC and CRH mRNA in the fetal pituitary or hypothalamus.
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PMID:Effects of repeated maternal betamethasone administration on growth and hypothalamic-pituitary-adrenal function of the ovine fetus at term. 1075 38

We tested the hypothesis that labor-induced epinephrine release would stimulate alveolar fluid clearance in preterm fetuses. Preterm fetuses were obtained by cesarean section from timed-pregnant guinea pigs at 61-69 days postconception. Fetal guinea pigs were euthanized and placed on continuous positive airway pressure oxygenation, and an isosmolar 5% albumin solution was instilled. Alveolar fluid clearance was measured over 1 h. The fetal lung began to absorb fluid at 64-66 days postconception, and at birth, alveolar fluid clearance quadrupled. Baseline alveolar fluid clearance when present was sensitive to propranolol inhibition and depended on beta-adrenergic stimulation. Measurements of plasma epinephrine in fetal animals confirmed high epinephrine levels in 66- to 69-day postconception fetuses. Prenatal alveolar fluid clearance when present was highly amiloride sensitive, suggesting that amiloride-sensitive Na+ channels were critical. Oxytocin-induced labor initiated an amiloride- and propranolol-sensitive net alveolar fluid clearance in 61-day-gestation animals. Moreover, oxytocin induced significant epinephrine release in all fetuses. These results have clinical implications for infants delivered by cesarean section before the onset of labor. Use of pharmacological agents to induce labor may reduce the occurrence and severity of perinatal respiratory distress.
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PMID:Alveolar fluid clearance in late-gestational guinea pigs after labor induction: mechanisms and regulation. 1123 99

Obstetrical and perinatal outcomes in newborns of diabetic pregnant women depend on metabolic control and fetal surveillance during pregnancy. The effects of fetal surveillance on perinatal mortality and morbidity was analyzed in diabetic pregnant women with appropriate glucose control in our regional center for diabetes and pregnancy. 480 deliveries complicated by frank or gestational diabetes occurred in our Department in the period of 1988-1999. Perinatal mortality and morbidity, prevalence of premature deliveries, methods of fetal surveillance, options for respiratory distress syndrome (RDS) profilaxis, cesarean section rate, timing of delivery and its indications and occurrence of malformations have been analyzed. It was found that malformation rate and perinatal mortality may be reduced to even lower level than that of in healthy pregnant women by appropriate glucose control and by using the latest methods of intrauterine fetal surveillance including cardiotocography (non stress test and oxytocin challenge test), doppler fetal artery velocimetry and fetal pulse oximetry. Timing of delivery was needed in 35% of the cases with IDDM and 15% of gestational diabetes due to chronic placental insufficiency. If labour induction was needed before the 38 weeks, amniocentesis was performed to test fetal lung maturity. Direct fetal glucocorticoid administration was used to enhance fetal lung maturation in 14 cases. C-section rate was slightly higher than that of in non diabetic pregnant women. Our perinatal morbidity data (macrosomia, hyperbilirubinemia, hypoglycemia, injuries, infections) are comparable with the data from the literature. Although perinatal mortality with the help of thorough fetal surveillance is even better in diabetic pregnant women than in non diabetic patients, future eye should be focused on factors affecting perinatal morbidity, because it is still higher than in newborns of healthy mothers.
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PMID:Improvement of perinatal outcome in diabetic pregnant women. 1175 14

Preterm birth is associated with up to 90% of perinatal deaths. In spite of numerous clinical and preclinical research programs, its incidence has not changed throughout the past decade. An observation that the oxytocin antagonist atosiban delays preterm labor and is significantly more potent than vasopressin(1a) receptors gave rise to research on the role of vasopressin blockade in tocolysis and vasopressin itself in preterm labor. Successful tocolysis allows the introduction of intrauterine steroid treatment of the fetus, which reduces the chance of developing infant respiratory distress syndrome and intracranial hemorrhage. Fetal membranes, decidua and placenta are considered a possible site of initiation of parturition, both term and preterm. Research on the biology of these tissues may shed new light on current concepts of the pathophysiology of preterm labor. We here present a short review on the role of oxytocin, oxytocin receptor blockade and fetal membranes in preterm labor.
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PMID:Oxytocin and fetal membranes in preterm labor: current concepts and clinical implication. 1285 35


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