Absence Of Uterine Contractions Research Articles

The impact of clinical management type on maternal and neo-natal outcome following pre-labour rupture of membranes at term

To investigate the impact of home compared to hospital conservative management on maternal and neonatal outcome on women with pre-labour rupture of membranes (PROM) at term. A randomised, controlled trial, participants were randomly allocated to one of the following two arms of clinical intervention, hospital management group (N = 27) or home management group (N = 29). The dependent variables were established clinical indices of maternal and neonatal outcome. 56 women admitted to the maternity unit of a north east England maternity hospital with confirmed PROM. All participants were over 37 weeks gestation (mean 39.08, SD 1.08), with a singleton pregnancy of cephalic presentation and no apparent medical or obstetric contra-indications and absence of uterine contractions. No significant differences were found between groups in maternal high vaginal swab infection rates, neonatal infection screen or Apgar scores. No other statistically significant differences between groups were observed on any of the key clinical outcome maternal or neonatal indices. This study provides empirical evidence that women allowed home for the period of expectant management are at no greater risk from adverse maternal or neonatal outcomes than their counterparts who remained in hospital. This has important clinical implications for the management of PROM at term. The direction of future research in this area is indicated.

Autonomic modulation of insulin levels in foetal sheep

The autonomic nervous system plays an important part in metabolic and circulatory adaptation of the foetus to changes in its intrauterine environment and after delivery. Foetal and neonatal glucose metabolism and insulin secretion are influenced by changes in humoral catecholamine levels as they may occur during asphyxia. To assess the role of neuronal and humoral sympathetic activity in foetal endocrine pancreatic regulation, chronically catheterized foetal sheep near term were chemically sympathectomized with 6-hydroxydopamine. Experiments were carried out in unanaesthetized foetal sheep in utero in the absence of uterine contractions. Insulin and glucose levels, blood gases, acid-base status and catecholamines were measured before, during and after a 2 min occlusion of uterine blood flow caused by mechanical constriction of the maternal aorta. Pancreatic blood flow was determined using radioactive labelled microspheres. During normoxaemia, insulin levels, pancreatic blood flow and glucose transport to the organ in sympathectomized foetuses were elevated compared with intact animals, whereas glucose concentrations did not show any significant differences. After the onset of asphyxia humoral catecholamine levels rose significantly in both groups. Insulin concentrations in the plasma of both intact and sympathectomized foetuses were no longer different indicating both indirect (blood flow and humoral catecholamine related) and direct (neurally mediated) sympathetic effects on pancreatic beta cells.

A Comparison of Syntocinon Infusion with Prostaglandin Vaginal Pessaries When Spontaneous Rupture of the Membranes Occurs Without Labour After 34 Weeks Gestation

In a prospective randomized trial of 106 patients who had spontaneously ruptured their membranes greater than or equal to 4 hours in the absence of labour, vaginal prostaglandin E2 pessaries and intravenous Syntocinon were compared. There was no significant difference in the treatment to delivery times between the 2 groups. The number of operative deliveries in each group were comparable. No untoward side-effects were noted. The use of vaginal prostaglandin E2 tablets appears to be a safe alternative to Syntocinon for induction of labour when spontaneous rupture of membranes has occurred in the absence of uterine contractions.

Preterm ruptured membranes, no contractions

SummaryIn a random prospective trial the prophylactic me of oral ritodrine or cephalexin was found to be of no advantage to the newborn with preterm premature rupture of the membranes in the absence of uterine contractions.

Cervical softening in late pregnant sheep by infusion of prostaglandin E-2 into a cervical artery.

Cervical softening was induced in late pregnant sheep by infusion of PGE-2 into a cervical artery. The effect of this treatment was assessed by measurement of the extensibility in vitro of a strip of cervical tissue. After infusion of a saline/ethanol mixture extensibility was 2.84 X 10(-3) +/- 0.3 X 10(-3) min-1 (mean +/- s.e.m., N = 5); after infusion of PGE-2 it increased significantly (P less than 0.02) to 8.6 X 10(-3) +/- 1.8 X 10(-3) min-1 (N = 6). Infusion of PGE-2 did not increase uterine activity, and there was no significant change in the concentration of progesterone in the maternal jugular venous plasma. These data suggest that PGE-2 might act as a mediator of cervical softening in vivo and show that the cervix can soften in the absence of uterine contractions.

Multiple dose extraamniotic prostaglandin gel for second trimester termination of pregnancy.

Multiple doses of PGF2 alpha gel were administered into the extraamniotic space in 30 patients to induce mid-trimester termination of pregnancy. In 18 of these patients, repeat doses of gel were given only in the absence of uterine contractions and in 12 patients the gel was administered every 4 hours, irrespective of uterine activity. The mean time to abortion in all patients was 13.9 hours; no benefit seemed to accrue from using routine 4-hourly doses and it is recommended that repeat doses are given only when contractions are absent. The latter technique compares favourably with the use of other natural prostaglandins and prostaglandin analogues.

Antepartum fetal heart rate monitoring. II. Deceleration patterns.

Fetal heart rate was studied during the antepartum period in 246 patients, yielding a total of 1964 recordings. The following parameters were evaluated and correlated: --the semi-quantitative assessment of fetal heart rate instability (as expressed by the percentage of duration of flat traces); --the presence of decelerations and their relationship to the presence or absence of uterine contractions; --the neonatal condition. Overall, 50% of the patients exhibited uterine contractions while 30% contained decelerations patterns either occurring spontaneously or in association with uterine contractions. A definite relationship was observed between the presence of severe decelerations (irrespective of the time relationship with any uterine contraction) and poor neonatal outcome. A relationship does exist between the presence of severe decelerations and flattening in the recording, which, as demonstrated in the previous part of the paper also exhibited a strong positive relationship with the neonatal outcome. When one considers the different degrees of flattening, it appears that a further correlation between decelerations and neonatal state is demonstrable only in the case of a 10--50% flat recording. Here the probability of a distressed baby is 20% in the absence of decelerations, but 43.4% in the presence of decelerations. In other cases (i.e., less than a 10% or more than a 50% flat recording) the pronostic significance of the instability of the record is not significantly modified by he presence or absence of decelerations. These results indicate that consideration of decelerations is only advisable in these cases where instability is moderately affected (flattening in 10-50% of the record) and that the use of the oxytocin challenge test OCT may be reserved for such cases, when these are neither spontaneous contractions nor decelerations and not contraindications present.

The flow resistance of the spiral artery and the related intervillous space in the rhesus monkey placenta.

Uteroplacental arteries of 4 rhesus monkeys were cannulated at their myometrical portions and perfused with dextran solutions and blood. Pressure-flow curves were obtained for the spiral artery and the related intervillous space, i.e. for the functional cotyledonary unit of the haemochorial villous placenta. For a flow of 3 ml.min-1, which is probably the normal rate of flow through the spiral artery, the pressure at the entry of the spiral artery was found to be 13--18 mm Hg (1.7--2.4kPa) during uterine relaxation (uterine diastole). There was a direct proportional relationship between the spiral artery flow and the pressure difference between the spiral artery and the amniotic fluid; the pressure difference per flow (the resistance of the cotyledonary unit) was found to be 1--3 mm Hg . ml-1 . min (8--24kPa . ml-1 . s). It is concluded that the spiral artery and the related intervillous space do not offer a limiting resistance to maternal blood flow in the absence of uterine contractions.

The effect of beta-receptor-stimulating agents on the utero-placental blood flow.

The influence of salbutamol, a beta-2-receptor-stimulating agent, on the blood flow through the utero-placental unit was evaluated in the human. Serial placenta scintigrams were analysed quantitatively, after injection of 0.5 mCi Indium-113m, by means of a gamma-camera connected on line to a computer. The examinations were performed in the third trimester of pregnancy. No sedation was used. Uterine contractions were not present. Salbutamol caused an increase in activity over the placental region, corresponding to a 15% increase in blood volume. The rise time of the initial phase of isotope accumulation (calculated from 5 to 95% of final activity) was prolonged by 100% during salbutamol infusion. As the rise time is proportional to the volume/flow ratio of blood in the uteroplacental region, our data indicate that salbutamol infusion causes a decrease in blood flow in the absence of uterine contractions.

Epidural anesthesia in the normotensive pregnant ewe: Effects on uterine blood flow and fetal acid-base status.

Lumbar epidural anesthesia was administered to 12 normotensive pregnant ewes. Blood pressure was maintained by intravenous fluid infusion. Six ewes received anesthesia with 1.5 per cent 2-chloroprocaine with 1:100,000 epinephrine and the remaining six received 1.5 per cent 2-chloroprocaine without epinephrine. The sensory level of anesthesia was between the umbilicus and xiphisternum. Except for a transient 14 per cent decrease in uterine blood flow in the ewes receiving 2-chloroprocaine with epinephrine, uterine blood flow remained near control values and was sufficient at all times to maintain stable fetal acid-base and blood gas values. Provided blood pressure and uterine blood flow were stable, the percentage of uterine blood flow distributed to the placenta in the absence of uterine contractions was not altered by epidural anesthesia or by addition of epinephrine to the anesthetic solution.

Hypofibrinogenemia in the dead fetus syndrome treated with aminocaproic acid

A case of dead fetus syndrome with hyperfibrinogenemia and increased fibrinolytic activity has been presented. A profound clotting failure occurred in this patient even in the absence of uterine contractions where presumably thromboplastin and fibrinolytic substances are rapidly extruded into the maternal circulation. The patient was observed for 6 weeks prior to delivery, and the erythroblastotic fetus was found to have been dead for approximately 5 weeks. The thrombin time test and the blood clot lysis test are satisfactory, but the “Fi” test is recommended as an aid to diagnosis. An adequate fibrinogen level was not necessarily synonymous with effective hemos tasis until the addition of aminocaproic acid decreased the elevated fibrinolytic activity. A case of dead fetus syndrome with hyperfibrinogenemia and increased fibrinolytic activity has been presented. A profound clotting failure occurred in this patient even in the absence of uterine contractions where presumably thromboplastin and fibrinolytic substances are rapidly extruded into the maternal circulation. The patient was observed for 6 weeks prior to delivery, and the erythroblastotic fetus was found to have been dead for approximately 5 weeks. The thrombin time test and the blood clot lysis test are satisfactory, but the “Fi” test is recommended as an aid to diagnosis. An adequate fibrinogen level was not necessarily synonymous with effective hemos tasis until the addition of aminocaproic acid decreased the elevated fibrinolytic activity.