Effect of Propranolol on Exercise Tolerance of Patients with Atrial Fibrillation

Six patients with atrial fibrillation who were taking digitalis were exercised before and after 30 mg. of propranolol twice daily. Though there was a lower pulse rate at rest and on exercise in all patients, three suffered deterioration of exercise tolerance. It is concluded that propranolol does not improve the exercise tolerance of patients with atrial fibrillation whose resting ventricular rate is controlled with digitalis.     

Severe Adverse Maternal Outcomes among Women in Midwife-Led versus Obstetrician-Led Care at the Onset of Labour in the Netherlands: A Nationwide Cohort Study

ObjectiveTo test the hypothesis that it is possible to select a group of low risk women who can start labour in midwife-led care without having increased rates of severe adverse maternal outcomes compared to women who start labour in secondary care.ResultsNulliparous and parous women who started labour in midwife-led care had lower rates of SAMM, postpartum haemorrhage and manual removal of placenta compared to women who started labour in secondary care. For SAMM the adjusted odds ratio’s and 95% confidence intervals were for nulliparous women: 0.57 (0.45 to 0.71) and for parous women 0.47 (0.36 to 0.62).ConclusionsOur results suggest that it is possible to identify a group of women at low risk of obstetric complications who may benefit from midwife-led care. Women can be reassured that we found no evidence that midwife-led care at the onset of labour is unsafe for women in a maternity care system with a well developed risk selection and referral system.     

Outcome of planned home births in an inner city practice.

OBJECTIVE--To assess the outcome of pregnancy for women booking for home births in an inner London practice between 1977 and 1989. DESIGN--Retrospective review of practice obstetric records. SETTING--A general practice in London. SUBJECTS--285 women registered with the practice or referred by neighbouring general practitioners or local community midwives. MAIN OUTCOME MEASURES--Place of birth and number of cases transferred to specialist care before, during, and after labour. RESULTS--Of 285 women who booked for home births, eight left the practice area before the onset of labour, giving a study population of 277 women. Six had spontaneous abortions, 26 were transferred to specialist care during pregnancy, another 26 were transferred during labour, and four were transferred in the postpartum period. 215 women (77.6%, 95% confidence interval 72.7 to 82.5) had normal births at home without needing specialist help. Transfer to specialist care during pregnancy was not significantly related to parity, but nulliparous women were significantly more likely to require transfer during labour (p = 0.00002). Postnatal complications requiring specialist attention were uncommon among mothers delivered at home (four cases) and rare among their babies (three cases). CONCLUSIONS--Birth at home is practical and safe for a self selected population of multiparous women, but nulliparous women are more likely to require transfer to hospital during labour because of delay in labour. Close cooperation between the general practitioner and both community midwives and hospital obstetricians is important in minimising the risks of trial of labour at home.     

Effects of social support during parturition on maternal and infant morbidity.

Because continuous social support during labour is a component of care in many societies but inconsistent in our own, the clinical effect of support during labour on maternal and neonatal morbidity were studied. Social support was provided by female companions. Four hundred and sixty five healthy primigravidous women were enrolled using a randomised design. Compared with 249 women undergoing labour alone 168 women who had supportive female companions throughout labour had significantly fewer perinatal complications (p less than 0.001), including caesarean sections (7% v 17%, p less than 0.01) and oxytocin augmentation (2% v 13%, p less than 0.001), and fewer infants admitted to neonatal intensive care (p less than 0.10). Of the women who had an uncomplicated labour and delivery requiring no interventions, those with a companion had a significantly shorter duration of labour (7.7 hours v 15.5 hours, p less than 0.001). This study suggests that constant human support may be of great benefit to women during labour.     

Progesterone and oestradiol levels and cytoplasmic receptor concentrations in the human myometrium at term, before labour and during labour

Progesterone (P) and oestradiol (E2) cytoplasmic receptor levels in the myometrium of 12 women, who underwent cesarean section at term were determined by means of an exchange assay. Six of the women had an elective cesarean section, and the other six were in active labour when the operation was performed. Both the P and the E2 receptor concentrations were significantly higher in the myometrium of those women who were in labour. The plasma P and E2 levels did not change before labour and during labour. The myometrial E2 concentrations were also similar in both groups. The myometrial P concentration was lower in the labour group, but the difference was not statistically significant. This study is the first which compares the steroid receptor levels at term before labour and during labour in human myometrium, although only the unbound and the cytosol receptor levels were determined. The change of levels in receptor concentrations could be a sign of the decrease of the P dominance in the myometrium during labour.     

Perineal massage in labour and prevention of perineal trauma: randomised controlled trial

ObjectiveTo determine the effects of perineal massage in the second stage of labour on perineal outcomes.DesignRandomised controlled trial.ParticipantsAt 36 weeks'' gestation, women expecting normal birth of a singleton were asked to join the study. Women became eligible to be randomised in labour if they progressed to full dilatation of the cervix or 8 cm or more if nulliparous or 5 cm or more if multiparous. 1340 were randomised into the trial.InterventionMassage and stretching of the perineum during the second stage of labour with a water soluble lubricant.ResultsRates of intact perineums, first and second degree tears, and episiotomies were similar in the massage and the control groups. There were fewer third degree tears in the massage group (12 (1.7%) v 23 (3.6%); absolute risk 2.11, relative risk 0.45; 95% confidence interval 0.23 to 0.93, P<0.04), though the trial was underpowered to measure this rarer outcome. Groups did not differ in any of the secondary outcomes at the three assessment points.ConclusionsThe practice of perineal massage in labour does not increase the likelihood of an intact perineum or reduce the risk of pain, dyspareunia, or urinary and faecal problems.

What is already known on this topic

Perineal trauma during vaginal birth and its sequelae, including urinary and faecal incontinence, dyspareunia, and persistent pain, have a negative impact on the sexuality, self esteem, and quality of life of countless women each yearPerineal massage conducted antenatally has some benefit in reducing the risk of perineal traumaPerineal massage in the second stage of labour has been promoted and practised without sound evidence of its effectiveness

What this study adds

Perineal massage in the second stage of labour did not have any effect on the likelihood of an intact perineum, perineal trauma, pain, or subsequent sexual, urinary or faecal outcomes but was not harmfulThe results support midwives in following their usual practice while taking account of the preferences of individual women     

Severity of labour pain: influence of physical as well as psychologic variables.

The role of physical factors in the severity of labour pain has been neglected. The amount of cervical dilation, the frequency of the contractions, the woman''s height and usual weight before the pregnancy and other physical factors were therefore examined in relation to the intensity of labour pain in 141 primiparous and 99 multiparous women. In general, pain increased gradually during labour in both groups of women, though the severity of the pain was lower in the women who had received prepared childbirth training than in those who had not. Although the average pain scores in this study were high, there were striking individual differences, some women having extremely severe pain and others having almost none. The pain scores in both groups of women were significantly correlated with the ratios of the women''s usual weight to height. In the multiparous women the scores were also correlated with the woman''s usual weight and the baby''s weight but not with the woman''s weight gain during pregnancy. Thus, the results show that physical as well as psychologic factors contribute to the severity of labour pain.     

Appearance of Prostaglandin F2α in Human Blood during Labour

Blood samples from over 70 pregnant women have been examined for the presence of four prostaglandins. Samples obtained from women not in labour at different gestation periods and at term contained no detectable amounts of prostaglandins. Prostaglandin F_2α was present in samples of blood obtained during normal spontaneous labour. The appearance of this substance in the blood preceded the uterine contraction. Whether prostaglandins play a part in the process of normal labour is still conjectural.     

Psychosocial stress in pregnancy and its relation to the onset of premature labour.

A modified life events inventory was presented over a four-month period to 132 consecutive women going into spontaneous labour in Hull and Manchester. Three study groups were identified according to the duration of pregnancy. The levels of psychosocial stress in pregnancy were found to be particularly high in the mothers whose babies were born preterm. Stressful events may precipitate preterm labour in some women. The concept of antenatal care may have to be broadened if the incidence of premature labour and resulting perinatal mortality are to be reduced.     

Midwife managed delivery unit: a randomised controlled comparison with consultant led care.

OBJECTIVE--To examine whether intrapartum care and delivery of low risk women in a midwife managed delivery unit differs from that in a consultant led labour ward. DESIGN--Pragmatic randomised controlled trial. Subjects were randomised in a 2:1 ratio between the midwives unit and the labour ward. SETTING--Aberdeen Maternity Hospital, Grampian. SUBJECTS--2844 low risk women, as defined by existing booking criteria for general practitioner units in Grampian. 1900 women were randomised to the midwives unit and 944 to the labour ward. MAIN OUTCOME MEASURES--Maternal and perinatal morbidity. RESULTS--Of the women randomised to the midwives unit, 647 (34%) were transferred to the labour ward antepartum, 303 (16%) were transferred intrapartum, and 80 (4%) were lost to follow up. 870 women (46%) were delivered in the midwives unit. Primigravid women (255/596, 43%) were significantly more likely to be transferred intrapartum than multi-gravid women (48/577, 8%). Significant differences between the midwives unit and labour ward were found in monitoring, fetal distress, analgesia, mobility, and use of episiotomy. There were no significant differences in mode of delivery or fetal outcome. CONCLUSIONS--Midwife managed intrapartum care for low risk women results in more mobility and less intervention with no increase in neonatal morbidity. However, the high rate of transfer shows that antenatal criteria are unable to determine who will remain at low risk throughout pregnancy and labour.     

Delivery after caesarean section: review of 2176 consecutive cases.

A total of 2176 consecutive patients who had had one previous caesarean section were studied retrospectively. A repeat elective caesarean section was performed in 395 (18.2%). Labour started spontaneously in 1363 patients, 301 of whom were given oxytocin to accelerate inert labour, and was induced by amniotomy and infusion of oxytocin in 418 women; 1618 of these 1781 patients (90.8%) delivered vaginally. Patients who had had a previous vaginal delivery were more likely to deliver vaginally again. Those women in whom the initial caesarean section had been performed during labour before the cervix was 4 cm dilated were less likely to deliver vaginally than those who had progressed further in labour or those who had had an elective caesarean section. Similarly, those who received oxytocin to stimulate inert labour were more likely to require a repeat caesarean section than those who did not. The uterine scar ruptured in only eight (0.45%) of the 1781 patients allowed into labour. The risk of rupture of the scar was not increased by the use of oxytocin alone either to induce or to accelerate labour. The combination of oxytocin to accelerate labour and epidural analgesia to provide pain relief, however, was associated with an increased incidence of scar rupture. Labour may be safely allowed in women who have had a previous caesarean section, most of whom will deliver vaginally. Induction of labour does not increase the risk of either a repeat caesarean section or rupture of a uterine scar.     

Expression of scaffolding, signalling and contractile-filament proteins in human myometria: effects of pregnancy and labour

Successful parturition requires the co-ordination of numerous myometrial signalling events to allow for timely and efficient uterine contractions. Late pregnancy and labour onset in humans may be associated with changes in the expression of myometrial proteins implicated in such uterine contractile signal integration. Accordingly, in myometria from non-pregnant women and pregnant women, not in labour or in labour, we examined the content of putative plasmalemmal scaffolding proteins (caveolin-1 and -2) and compared these to the proportions of signal transducing rho-associated kinases (ROKalpha and beta) and contractile filament-associated proteins alpha-actin, myosin regulatory light chain (MLC(20)) and h-caldesmon. There was no effect of pregnancy or labour on the proportion of caveolin, ROK betaor alpha-actin. However, pregnancy was associated with a decrease in ROKalpha and MLC(20) such that ROK alpha: alpha-actin and MLC(20): alpha-actin ratios were reduced compared to myometria of non-pregnant women. In contrast, h-caldesmon was up-regulated in pregnancy resulting in an elevated h-caldesmon: alpha-actin ratio. There were, however, no further significant changes in ROK alpha, MLC(20) or h-caldesmon expression with spontaneous or oxytocin-induced labour. These data suggest that the mechanism(s) integrating myometrial signalling events with the onset of human labour does not involve differential alterations of the cellular expressions of caveolins, ROK, alpha-actin, MLC(20) or h-caldesmon.     

Association of the positive inotropic action of ouabain with a second species of digitalis receptors

Studies were conducted to determine whether Na-K ATPase or a second species of digitalis receptors in canine cardiac sarcolemma membrane preparations is associated with the positive inotropic action of nontoxic concentrations of ouabain. [3H]ouabain association and dissociation experiments using highly enriched sarcolemma preparations from canine ventricle indicate the presence of two species of ouabain binding receptors. Ouabain binding to Na-K ATPase of the sarcolemma preparation requires supporting ligands and is characterized by fast association and very slow dissociation in vitro. The second species of digitalis receptor does not require supporting ligands for ouabain binding and is characterized by slow association and fast dissociation. To determine which species of digitalis receptor is associated with the positive inotropic action of digitalis, ouabain washout experiments were conducted using various isolated canine myocardial preparations. Washout of the positive inotropic effects of 1.2-2.4 X 10(-7) M ouabain gave half-life values of 1.5-2.0 h for the various myocardial preparations. [3H]ouabain dissociation from the second species of digitalis receptors gave half-life values of 1.7-1.8 h, whereas dissociation from the sarcolemma Na-K ATPase gave half-life values of 8.9-9.3 h for the various sarcolemma preparations utilized. Therefore, based on similarities in half-life values between ouabain inotropy and [3H]ouabain dissociation from the second class of digitalis receptors, it is postulated that the positive inotropic action of digitalis glycosides is associated with the second species of digitalis receptors in the sarcolemma and not with the digitalis inhibitory receptor of Na-K ATPase for nontoxic concentrations of digitalis.     

Liquid membrane phenomenon in the actions of digitalis

The liquid membrane phenomenon in the actions of digitalis glycosides (digitoxin, digoxin and ouabain) has been studied. Formation of liquid membranes, in series with a supporting membrane, by digitalis alone and by digitalis in association with lecithin and cholesterol has been demonstrated. The results obtained on the transport of relevant permeants, viz. sodium, potassium and calcium ions and dopamine, adrenaline, noradrenaline and serotonin, in the presence of the liquid membrane generated by digitalis in association with lecithin and cholesterol indicate that the liquid membrane barrier to transport may have a relevance with the biological actions of digitalis.     

Are isolated maternity units run by general practitioners dangerous?

A retrospective survey was carried out of women admitted in labour to an isolated maternity unit run by general practitioners in Penrith. In the five years 1980-4, 1267 women began labour in Penrith, of whom 1153 (91%) never required help from a consultant unit. Ninety required transfer during labour. Ten mothers and four neonates required transfer during the early puerperium, all to one receiving unit in Carlisle. There were six perinatal deaths during the five years; five occurred in babies delivered after transfer. The perinatal mortality was 4.7/1000. The low mortality, the low level of intervention, and the preference of women all support the retention of isolated units.     

Immunophenotyping and activation status of maternal peripheral blood leukocytes during pregnancy and labour,both term and preterm

The onset of labour in rodents and in humans is associated with physiological inflammation which is manifested by infiltration of activated maternal peripheral leukocytes (mPLs) into uterine tissues. Here, we used flow cytometry to immunophenotype mPLs throughout gestation and labour, both term and preterm. Peripheral blood was collected from non‐pregnant women and pregnant women in the 1st, 2nd and 3rd trimesters. Samples were also collected from women in active labour at term (TL) or preterm (PTL) and compared with women term not‐in‐labour (TNIL) and preterm not‐in‐labour (PTNIL). Different leukocyte populations were identified by surface markers such as CD45, CD14, CD15, CD3, CD4, CD8, CD19 and CD56. Their activation status was measured by the expression levels of CD11b, CD44, CD55, CD181 and CD192 proteins. Of all circulating CD45+ leukocytes, we detected significant increases in CD15+ granulocytes (i) in pregnant women versus non‐pregnant; (ii) in TL women versus TNIL and versus pregnant women in the 1st/2nd/3rd trimester; (iii) in PTL women versus PTNIL. TL was characterized by (iv) increased expressions of CD11b, CD55 and CD192 on granulocytes; (v) increased mean fluorescent intensity (MFI) of CD55 and CD192 on monocytes; (vi) increased CD44 MFI on CD3+ lymphocytes as compared to late gestation. In summary, we have identified sub‐populations of mPLs that are specifically activated in association with gestation (granulocytes) or with the onset of labour (granulocytes, monocytes and lymphocytes). Additionally, beta regression analysis created a set of reference values to rank this association between immune markers of pregnancy and to identify activation status with potential prognostic and diagnostic capability.     

Inducing labour with vaginally administered prostaglandin E2.

In 50 consecutive pregnant women at a 125-bed community hospital with 1000 deliveries annually, labour was induced with prostaglandin E2 administered intravaginally. There were no stillbirths or neonatal deaths, and complications in the mothers were few. In nine women (18%) oxytocin was subsequently administered because of a failure of labour to progress; in spite of this, cesarean section was required in two (4%) of the patients. The overall cesarean section rate was 6%. Prostaglandins have been used routinely to induce labour in the United Kingdom for several years. This noninvasive method is safe, effective and well received by women in a community hospital setting, including those wanting "natural childbirth".     

Randomised controlled trial of cardiotocography versus Doppler auscultation of fetal heart at admission in labour in low risk obstetric population

ObjectiveTo compare the effect of admission cardiotocography and Doppler auscultation of the fetal heart on neonatal outcome and levels of obstetric intervention in a low risk obstetric population.DesignRandomised controlled trial.SettingObstetric unit of teaching hospitalParticipantsPregnant women who had no obstetric complications that warranted continuous monitoring of fetal heart rate in labour.InterventionWomen were randomised to receive either cardiotocography or Doppler auscultation of the fetal heart when they were admitted in spontaneous uncomplicated labour.ResultsThere were no significant differences in the incidence of metabolic acidosis or any other measure of neonatal outcome among women who remained at low risk when they were admitted in labour. However, compared with women who received Doppler auscultation, women who had admission cardiotocography were significantly more likely to have continuous fetal heart rate monitoring in labour (odds ratio 1.49, 95% confidence interval 1.26 to 1.76), augmentation of labour (1.26, 1.02 to 1.56), epidural analgesia (1.33, 1.10 to 1.61), and operative delivery (1.36, 1.12 to 1.65).ConclusionsCompared with Doppler auscultation of the fetal heart, admission cardiotocography does not benefit neonatal outcome in low risk women. Its use results in increased obstetric intervention, including operative delivery.

What is already known on this topic

The admission cardiotocogram is a short recording of the fetal heart rate immediately after admission to the labour wardOpinion varies about its value in identifying a potentially compromised fetusIn low risk women, the incidence of intrapartum fetal compromise is low

What this study adds

Compared with Doppler auscultation of the fetal heart, admission cardiotocography has no benefit on neonatal outcome in low risk womenAdmission cardiotocography results in increased obstetric intervention, including operative delivery     

Women's views on the impact of operative delivery in the second stage of labour: qualitative interview study

Objective To obtain the views of women on the impact of operative delivery in the second stage of labour.Design Qualitative interview study.Setting Two urban teaching hospitals in the United Kingdom.Participants Purposive sample of 27 women who had undergone operative delivery in the second stage of labour between January 2000 and January 2002.Key themes Preparation for birth, understandings of the indications for operative delivery, and explanation or debriefing after birth.Results The women felt unprepared for operative delivery and thought that their birth plan or antenatal classes had not catered adequately for this event. They emphasised the importance of maintaining an open mind about the management of labour. They had difficulty understanding the need for operative delivery despite a review by medical and midwifery staff before discharge. Operative delivery had a noticeable impact on women''s views about future pregnancy and delivery.Conclusions Women consider postnatal debriefing and medical review important deficiencies in current care. Those who experienced operative delivery in the second stage of labour would welcome the opportunity to have a later review of their intrapartum care, physical recovery, and management of future pregnancies.     

Dissociation of Na+,K+-ATPase inhibition from digitalis inotropy.

Recent findings from our laboratory as well as those of other laboratories do not support the postulation that the mechanism of the positive inotropic action of digitalis is due to inhibition of NA,K-ATPase. Using short-acting digitalis steroids and drug washout experiments, in isolated myocardial preparations, it has been demonstrated that Na,K-ATPase isolated from such preparations is still significantly inhibited, whereas the positive inotropic effect is no longer present. Also, based on kinetic measurements the two exponential rate constants observed for drug half-life, a rapid and slow phase, were found to be associated, respectively, with the very short inotropic half-life and the very long enzyme inhibition half-life. In addition, a dissociation of the transient inotropic effects of digitalis was observed from the long lasting cardiotoxic effects of digitalis during drug washout. Moreover, a temporal correlation was noted between the persistent inhibitory effects of digitalis on Na,K-ATPase and the persistent cardiotoxic effects of digitalis. Therefore, it is concluded that inhibition of Na,K-ATPase is not responsible for the positive inotropic action of digitalis, but may be the mechanism, at least in part, for certain cardiotoxic effects of digitalis.