Uterine contractility in spontaneous and induced labour

Contractility parameters (uterine activity, contraction interval, amplitude, and frequency of contractions) were analyzed quantitatively during the active phase of first-stage of labour in 60 clinically normal term nulliparae with spontaneous or induced labour. Inductions were surgical (amniotomy alone) or by amniotomy combined with either intravenous oxytocin or prostaglandin administered intravenously (PGF 2alpha or PGE 2) or orally (PGE 2).     

Plasma prostaglandin metabolite concentrations in normal and dysfunctional labour

OBJECTIVE: To determine the concentrations of the metabolites of prostaglandin E2 (PGEM) and of prostaglandin F2 alpha (PGFM) prior to the onset of labour and during spontaneous labour, and to correlate the changes in concentrations of these metabolites with labour outcome. DESIGN: Longitudinal study throughout labour. SETTING: Labour ward of a large maternity unit. SUBJECTS: Seven primigravid and 11 parous women in the late third trimester with no signs of labour, and 17 primigravid and 11 parous women in spontaneous labour. INTERVENTIONS: Six of the primigravid women required augmentation with oxytocin because of dysfunctional labour. RESULTS: Before labour, parous women had significantly higher concentrations of both PGEM (P < 0.007) and PGFM (P < 0.006) compared with primigravid women. During labour, PGFM concentrations were significantly higher in both primigravid (P < 0.0002) and parous (P < 0.0001) women compared with the concentrations of these metabolites in women not in labour; the same was true for PGEM in primigravid (P < 0.003) but not in parous (P = 0.1) women. There was a small but significant increase (P < 0.02) in PGEM as labour progressed in both the normal groups. Amniotomy was associated with a significant increase in PGFM in primigravid and parous women (P < 0.002 and P < 0.009, respectively). The concentration of PGFM one hour following amniotomy correlated inversely with the amniotomy to delivery interval in both the normal primigravid (r = -0.624; P = 0.04) and the parous (r = 0.745; P = 0.021) groups. Women with dysfunctional labour showed no significant rise in PGEM or PGFM. Their PGFM concentrations were significantly lower than those seen in normal labour (P < 0.05). The concentration of PGFM in cord blood was significantly higher (P < 0.0001) in the parous women who laboured than in women delivered by elective caesarean section. There was no difference in the corresponding concentrations of PGEM (P = 0.9). CONCLUSIONS: These data show that spontaneous labour is associated with increased concentrations of prostaglandin metabolites in the maternal plasma, and are consistent with PGF2 alpha being an important stimulator of uterine contractility, with a relative deficiency of PGF2 alpha being associated with dysfunctional labour.     

A comparison of intravaginal misoprostol and intracervical prostaglandin E2 gel for ripening of unfavorable cervix and labor induction

OBJECTIVE: To study the effectiveness of single application of intravaginal misoprostol versus intracervical prostaglandin E2 gel for ripening the unfavorable cervix and labor induction. METHOD: One hundred and ten patients with indications for induction of labor with unfavorable cervices were randomized to receive either 100 microgram tablets of misoprostol placed in the posterior vaginal fornix or prostaglandin E2 1.5 mg in gel placed into the endocervix. Those, who were not in active labor after 24 hours, had labor induced with amniotomy and oxytocin. RESULTS: Among 110 patients recruited, 60 received misoprostol and 50 received prostaglandin E2 gel. The average interval from start of induction to vaginal delivery was 19.14 +/- 10.64 hours in misoprostol group and 21.37 +/- 13.09 hours in the prostaglandin E2 group (p = 0.33). Five patients (8%) in the misoprostol group had induction of labor after 24 hours of the treatment compared with 13 patients (26%) in the PGE2 group. The difference was significant (p = 0.03). Oxytocin augmentation was 35% in the misoprostol group and 34% in the prostaglandin E2 group (p = 0.86). There were no significant differences between routes of delivery. Nineteen patients (31%) in misoprostol group and 16 patients (32%) in the PGE2 gel group had cesarean deliveries. There was one case (1.7%) of uterine hyperstimulation in the misoprostol group and none in the PGE2 gel group. There were no significant difference in Apgar scores < 7 at 1 and 5 minutes, or admission to the neonatal intensive care unit between the 2 groups. CONCLUSION: Vaginal misoprostol is an effective agent for cervical ripening and induction of labor. Complications associated with prostaglandin administration were not statistically different between the 2 groups, but hyperstimulation occurred more in misoprostol group.     

Changing trends in the management of phaeochromocytoma

Sixty-one women making slow progress in the active phase of spontaneous labour with intact membranes were randomised to oxytocin and amniotomy, amniotomy only or expectant management. The data show that oxytocin significantly increases the rate of cervical dilatation and shortens prolonged labour, when compared with amniotomy alone and expectant management (P = 0.0144 and 0.0006, respectively). The impact on the operative delivery rate and neonatal outcome is difficult to assess due to the small number of relevant adverse outcomes. Women reported higher satisfaction score in the two groups where intervention followed the diagnosis of dysfunctional labour.     

Prostaglandins compared with oxytocin for induction of labour at term (author's transl)

12 cases of induction of labour with prostaglandin F2 alpha and 8 with prostaglandin E2 were compared with 14 cases in which induction was undertaken with oxytocin. All inductions were successful, the induction--delivery intervals being slightly shorter in the prostaglandin groups than in the oxytocin group. Both with prostaglandin F2 alpha and with prostaglandin E2 the cardiotocogram showed uterine hyperactivity in most of the cases with an unexpected, episodically-occurring increase in basal uterine tone and remarkable tachysystoly. Uterine hyper-activity led to fetal heart rate alterations of the "dip 2" type in about 50% of the cases. According to these results prostaglandins cannot be considered superior to oxytocin for the induction of labour at term.     

Relationship between quality of life instruments, health state utilities, and willingness to pay in patients with asthma

OBJECTIVES: To estimate the effects among nulliparae of early augmentation with amniotomy and oxytocin on caesarean delivery, and on other indicators of maternal and neonatal morbidity including transfusion. Apgar score < 7 at 5 minutes, and admission to the special care nursery. DESIGN: Meta-analysis. METHODS: Published studies were identified through manual and computerised searches. Two unpublished studies were identified through direct communication with the investigators. Twelve trials were identified which compared a policy of early labour augmentation including amniotomy followed by oxytocin with a less active form of management. Two methodologically unacceptable studies were excluded. Studies were grouped according to whether they admitted only women with abnormal progress (therapy trials: n = 3) or accepted women with normal labour (prevention trials: n = 7). RESULTS: Unstratified analysis did not provide support for the hypothesis that early augmentation reduces the risk of caesarean section (typical odds ratio [OR] 0.9; 95% CI 0.7-1.1). The typical odds ratio for prevention trials was similar to that obtained in the unstratified analysis (typical OR 0.9, 95% CI 0.7-1.2). Although only a small number of women have been randomised in therapy trials, a trend toward a reduction in the rate of caesarean section with early intervention was seen in this group (typical OR 0.6, 95% CI 0.2-1.4). CONCLUSIONS: Early augmentation does not appear to provide benefit over a more conservative form of management in the context of care of nulliparous women with mild delays in the progress of labour. In the context of established delay in labour, an active policy of augmentation may reduce the risk of caesarean section. However, only three small trials have been performed in this context, and they do not have adequate power to allow firm conclusions to be drawn.     

Can deliveries at risk be selected at smaller delivery units?

In order to explore the possibility of converting a delivery unit at a small hospital to a maternity home, we examined the medical records of those women who delivered by Caesarean section, forceps or vacuum extraction at Lofoten hospital during 1995. How many of these women might it have been necessary to transfer to an obstetrical department if Lofoten hospital had been a maternity home caring for low risk deliveries (primipara and multipara)? Out of a total of 271 deliveries (primiparas 98), 49 women delivered by Caesarean section (n = 35), forceps (n = 5) or vacuum extraction (n = 9). Using risk assessment, 22 women (45%) would have been selected for antenatal transfer, and 20 (41%) for intrapartum transport. For seven women no transfer would have been possible. These women would have delivered locally by vacuum extraction. Primipara versus multipara had a relative risk of 2.8 for Caesarean section or assisted vaginal delivery. It is estimated that 8-9% of the women would be selected prenatally for planned delivery at a hospital unit and that 7-8% would be transferred in labour if primiparas delivered at the maternity home. If primiparas were excluded, the proportions would be 41% and 1-2% respectively. In 1997 the delivery unit at Lofoten hospital was temporarily converted to a maternity home for a period of two years.     

Costs of intrapartum care in a midwife-managed delivery unit and a consultant-led labour ward

OBJECTIVE: to investigate whether there are differences between the cost of intrapartum care for women at low obstetric risk in a midwife-managed labour and delivery unit and that in a consultant-led labour and delivery ward. DESIGN: cost analysis based on the findings of a randomised controlled trial comparing two alternative types of intrapartum care. SETTING: Aberdeen Maternity Hospital, Grampian. SUBJECTS: the number of women 'booked' for care in the Midwives' Unit in a standard year and a comparable group of women cared for in the consultant-led labour ward. PRIMARY OUTCOME MEASURE: the cost 'outcome' is the extra (or reduced) cost per woman resulting from the introduction of a midwife-managed delivery unit. FINDINGS: the baseline extra cost of the introduction of the Midwives' Unit was found to be 40.71 pounds per woman. Depending on the scenario used, this ranged from a cost saving of 9.74 pounds per woman to an additional cost of 44.23 pounds per woman. CONCLUSIONS: this study has shown that, in terms of costs incurred during the intrapartum period, the marginal cost of caring for women at low obstetric risk alongside women at high obstetric risk in a standard labour ward is small. However, the impact of establishing a separate midwife-managed delivery unit, requiring an increase in midwifery staffing levels, can be significant.     

Induction of labor by intracervical prostaglandin gel and oxytocin infusion in primigravid women with unfavorable cervix

The rate of Cesarean Section for failed induction of labor and maternal and fetal compilations are high when labor is induced in a nulliparas women with an unripe cervix by amniotomy and oxytocin infusion. Prostaglandins (PG) in different forms have been used for ripening the cervix with an aim of reducing these problems. A prospective randomized trial was performed on one hundred primigravid women between 37 and 42 weeks of gestation with singleton pregnancy, cephalic presentation and unfavorable cervix (Modified Bishop Score < or = 5) in the department of Obstetrics & Gynaecology of Institute of Postgraduate Medicine & Research from 1st May 1996 to 30th April 1997. In this study the efficiency of prostaglandin E2 intracervical (PGE2 IC) gel in induction of labor in a group of primigravid women with unripe cervix was assessed and compared with another group with similar characteristics using oxytocin infusion and artificial rupture of membrane (ARM). The Modified Bishop Score (MBS), interval between IOL and onset of labor and the duration of labor after insertion of PGE2 gel was significantly different from those of oxytocin infusion group. But the Apgar Score at 1 & 5 min had shown no statistically significant difference. Any significant difference could also not be detected in the mode of delivery between the two induction group. The proportion of emergency Cesarean Section (CS) was high in the oxytocin infusion group than that of in the prostaglandin group. There was also no significant difference regarding the acceptability of both the induction methods.     

Prostaglandin E2 for cervical ripening: a randomized comparison of Cervidil versus Prepidil

OBJECTIVE: Our purpose was to compare the efficacy and safety of two standardized preparations of prostaglandin E2, Prepidil and Cervidil, for ripening of the cervix and initiation of labor. STUDY DESIGN: This was a prospective randomized study. Subjects in whom induction of labor was indicated were randomly assigned to receive either Prepidil (n = 36), an intracervical prostaglandin E2 gel, or Cervidil (n = 37), a controlled-release hydrogel pessary, as a cervical ripening agent. Inclusion criteria included (1) a Bishop score of < or = 7, (2) a cervix < 4 cm dilated, and (3) < or = 2 cm of cervical dilatation if effacement was > 70%. Each agent was administered according to the manufacturer's recommendations. RESULTS: There was no difference in Bishop scores between the two groups at the completion of the ripening process. The following mean times were shorter for the pessary group than for the gel group: (1) insertion of the ripening agent to vaginal delivery (20.6 vs 26.4 hours, p = 0.017), (2) time to achieve cervical ripening (11.1 vs 15.2 hours, p < 0.001), (3) time to achieve active labor (18.3 vs 25.5 hours, p = 0.019), and (4) hospital stay (3.7 vs 4.4 days, p = 0.03). Labor was initiated without the use of oxytocin in 24% of patients in the pessary group versus 3% of those in the gel group (p = 0.014). CONCLUSION: Both prostaglandin E2 agents are effective in achieving cervical ripening; however, the controlled-release pessary achieves ripening over a shorter time period. Furthermore, because time to achieve vaginal delivery and length of stay are shorter, the use of oxytocin is less frequent, and there is no increase in complications, the overall cost is expected to be less with the use of Cervidil as compared with Prepidil.     

Linkage mapping of Lims1l, the murine homolog of the human LIM domain gene PINCH, to mouse chromosome 10

In order to compare the efficacy of immediate intravenous oxytocin administration and intracervical prostaglandin E2 gel application in premature rupture of membranes with unfavorable cervices at term, 45 term pregnant patients with premature rupture of membranes were randomized into two groups. Twenty women received immediate intravenous oxytocin after cleansing enema while the rest were treated with intracervical prostaglandin E2 gel. Means of maternal age, gestational age, Bishop score at admission and the rates of nulliparity did not show any significant differences between the two groups (p > 0.05). The mean rupture to delivery time was 12.6 +/- 4.4 hours in the oxytocin group and 16.5 +/- 4.5 hours in the prostaglandin group (p < 0.01). Mean birth weights and Apgar scores were insignificant. Cesarean section rates were 24% in the oxytocin group and 5% in the other (p < 0.05). No infectious morbidity was seen in any case. In conclusion, although delivery is delayed with the intracervical prostaglandin approach, cesarean section rate is lowered without an increase in infectious morbidity.     

A breech delivery and induction with prostaglandin E2

Induction of labour with local application of PgE2 in breech presentation is still a much discussed problem. We aimed at studying the effect of local application of PgE2 (Prostin E2--3 mg) vaginal tablets for induction of labour in breech presentation. 15 pregnancies were studied and induced--8 for postdate, 6 for prae-eclampsia and 1 for fetal demise. Sonographic biometry and cardiotocographic examinations were conducted as well as a precise bishop score. Labour began within the interval of 3-13 hours after the application on the first tablet. The length of delivery was 4-24 hours. Effective labour was instituted in 93.33% on the parturiens, while in 1 (6.67%) there was a need for augmentation with oxytocin. There were no cases of hyperstimulation. Vaginal delivery was accomplished in 100% of the patients among which the breech was delivered with the classical manoeuvre in 10 cases and by the Bracht manoeuvre in 5 cases. Our results show, despite is small case number, that with favourable pelvic scores and absence of cephalopelvic disproportion and fetal distress PgE2 induction can be done locally even for breech presentation.     

Alcaligenes eutrophus as a bacterial chromate sensor

OBJECTIVE: Our purpose was to evaluate whether inserting prostaglandin E2 gel at the time of scheduled nonstress tests in patients with postdate pregnancies can decrease rates of intervention. STUDY DESIGN: A multicenter pilot study enrolled women with postdate pregnancies with Bishop score < or = 6 who were undergoing antepartum fetal heart rate testing. Patients were randomized in a double-blind fashion to receive either a prostaglandin E2 intracervical gel (Prepidil) or a placebo gel after each of their scheduled nonstress tests. RESULTS: There were no significant differences in the number of antepartum tests, labor inductions, or cesarean sections, the maximum oxytocin dosage, or the interval from admission to delivery in the prostaglandin E2 gel and placebo gel groups (n = 90). In the subset of patients with a Bishop score between 3 and 6 (63 patients), there were fewer inductions in the prostaglandin E2 group (30% vs 55%, P < .05). CONCLUSION: Application of prostaglandin E2 gel at the time of scheduled antepartum testing in patients with postdate pregnancies with unfavorable cervices decreased the induction rate only among patients with intermediate Bishop scores.     

Premature rupture of membranes at term with an unfavorable cervix: comparison of expectant management, vaginal prostaglandin, and oxytocin induction

BACKGROUND: Our objective was to determine the best treatment for parturients at term with an unfavorable cervix and premature rupture of membranes (PROM). METHODS: In this prospective study, 96 women with PROM and an unfavorable cervix were randomized into one of three treatment groups: oxytocin induction, vaginal prostaglandin E2 gel followed by oxytocin, or expectant management. RESULTS: Length of labor, cesarean section rate, and maternal/neonatal morbidity were not significantly different. In contrast, the interval from PROM until delivery and length of hospital stay were significantly longer in the expectantly managed group than in the other groups. Four of the patients who received expectant management required delivery because of nonreassuring fetal assessments. CONCLUSIONS: Expectant management of PROM at term significantly prolongs hospital stay without decreasing the incidence of abdominal delivery or infectious morbidity. There appears to be potential for cord compression in patients managed expectantly without continuous electronic fetal surveillance.     

A review and economic evaluation of bronchodilator delivery methods in hospitalized patients

BACKGROUND: Bronchodilator delivery by metered dose inhaler (MDI) to treat airflow obstruction is considered to be less expensive and as effective as nebulized therapy. OBJECTIVES: To document the utilization of bronchodilator delivery methods in a tertiary care Canadian university teaching hospital and to perform an economic evaluation. METHODS: A prospective 6-week audit of 4 preselected hospital wards (respiratory, thoracic surgery, general surgery, and a general internal medicine clinical teaching unit) and a cost-minimization economic evaluation were performed. Bronchodilator (salbutamol and ipratropium bromide) doses, frequency, and delivery methods, either MDI or wet nebulizer (WN), were recorded for 95 patients treated with aerosolized bronchodilators. Direct costs for medications and hourly wages including benefits and equipment were obtained. Time and motion studies identified time allocated to MDI and WN delivery. We used sensitivity analyses to test assumptions that could significantly affect treatment costs, especially assumptions about medications, labor, and spacer devices. Costs are expressed in Canadian dollars (Can$1 = US$0.75). RESULTS: Sixty-seven patients (70.5%) were treated with WN, 6 (6.3%) with MDI, and 22 (23.2%) with both WN and MDI. Self-administration of salbutamol by MDI was the least expensive: $1.27 for 200-microgram doses and $1.73 for 400-microgram doses compared with $2.62 for a 2.5-mg dose delivered by WN. The difference in cost between equivalent treatments (400-microgram MDI vs 2.5-mg WN) is only $0.89. Sensitivity analyses showed that MDI was the least expensive therapy when self-administration was possible and for all levels of supervision if more than 4 minutes was needed to administer a WN treatment. CONCLUSIONS: Bronchodilator delivery by WN is commonly prescribed for hospitalized patients despite evidence for equivalency of effect using MDI and in the absence of substitution protocols. Previous studies have estimated a far greater cost differential based on unrealistic labor estimates. We found that supervision of patients using MDIs minimized the differential cost between WN and MDI therapy and that cost savings are maximal in patients who can self-administer MDI therapy. Methodologically sound economic evaluations can better identify true cost savings and variables that need further study.     

A comparison of oral prostaglandin E2 and intravenous oxytocin for induction of labor in normal and high-risk pregnancies

The efficacy of oral prostaglandin E2 (PGE2) for induction of labor has been compared to that of intravenous oxytocin. There were 49 patients in each series. The over-all success rate with PGE2 is 82 per cent; with oxytocin, 65 per cent. PGE2 is at least as effective as oxytocin regardless of Bishop score or gravidity. There was no difference in the duration of labor in successful inductions with PGE2 or oxytocin. Nausea and diarrhea are more common with PGE2 but in only one case was this severe enough to warrent discontinuing the medication. One case of uterine hypertonus occurred in each series. No serious harmful effects on mother or fetus were noted with PGE2. These data support the concept that oral PGE2 administration is a safe and effective alternative to intravenous oxytocin for induction of labor in normal and high-risk pregnancies.     

Comparison of misoprostol and ricinus oil meal for cervical ripening and labor induction

OBJECTIVE: To compare the safety and efficacy of intravaginal prostaglandin E1, misoprostol with ricinus oil meal for labor induction. METHODS: Sixty patients with an indication for induction of labor were randomly assigned to two groups (30 cases each) induction with misoprotol, 50 micrograms intra-vaginally every 3 hours until active labor, or with that ricinus oil meal was taken. RESULTS: The time from start of induction to vaginal delivery was significantly shorter in the misoprostol group (12.2 vs 18.1, P < 0.05), and fewer patients in the misoprostol group required oxytocin augmentation (10.0% vs 40.0%, P < 0.05). The mean change in the Bishop score was significantly higher in those receiving misoprostol (5.5 vs 3.1, P < 0.05). Uterine tachysystole occurred more frequently in patients in the misoprostol group (16.7%) than in the ricinus oil meal group (3.0%). No significant differences were noted in the mode of delivery and patients of successful labor induction. CONCLUSIONS: Vaginally administered misoprostol is an effective agent for the cervical ripening and induction of labor.     

A randomized comparison of 15- and 40-minute dosing protocols for labor augmentation and induction

OBJECTIVE: To compare two low-dose oxytocin protocols in terms of fetal distress, uterine hyperstimulation, cesarean delivery rate, maximum dose of oxytocin, and length of labor. METHODS: We randomized 865 patients into 15-minute (incremental dose 1 mU/minute until 5 mU/minute, then 1 or 2 mU/minute) or 40-minute (incremental dose 1.5 mU/minute until 7 mU/minute, then 1.5 or 3.0 mU/minute) low-dose protocols. Before oxytocin use, all subjects were stratified according to parity and purpose of oxytocin, ie, for induction or augmentation of labor. RESULTS: The 40-minute dosing protocol had a significantly lower maximum dose of oxytocin (augmentation, 6.5 versus 8.2 mU/minute, P < .001; induction, 11.5 versus 14.5 mU/minute, P < .001), a lower incidence of uterine hyperstimulation (augmentation, 18.8 versus 31.8%, P < .001; induction, 19.1 versus 33.0%, P < .002), and less fetal distress (augmentation, 15.5 versus 26.1%, P < .005). No significant differences were found in the cesarean rate or length of labor. CONCLUSION: A dosing interval of 40 minutes led to lower incidences of uterine hyperstimulation and fetal distress, and decreased the maximum dose of oxytocin, without affecting the length of labor or the cesarean rate.     

Three methods of oxytocin-induced parturition and their effects of foals

OBJECTIVE: To compare effects of 3 oxytocin-based induction techniques on fetal and neonatal foals. DESIGN: Prospective randomized controlled trial. ANIMALS: 16 pregnant mares. PROCEDURE: Parturition was induced in mares by use of 3 treatments: group 1, 75 U of oxytocin, IM; group 2, 15 U of oxytocin, IM, q 15 minutes, for a maximum of 75 U; group 3, 75 U of oxytocin in 1 L of 0.9% NaCl solution IV (1 U/min), for a maximum of 75 U. Blood gas values and indices of vitality were measured in foals, and variables describing parturition were measured in mares. RESULTS: Group-3 mares had a shorter interval from administration of oxytocin to rupture of the chorioallantois (OTCA) than group-2 mares. More foals were abnormal when the interval from oxytocin administration to delivery of the foal (OTDE) was > or = 60 minutes. Arterial blood gas values, measurements of vitality, and plasma cortisol concentrations did not differ among foals in various treatment groups. Increased interval for OTCA and OTDE resulted in higher neonatal PaCO2, and a longer interval for OTCA resulted in lower arterial pH. Time required for birth was shorter in mares with a dilated cervix. More abnormal foals than normal foals were delivered after premature placental separation or dystocia. Abnormal foals took longer to stand and suckle than normal foals. Interval from delivery to suckling was positively correlated with OTCA, OTDE, and PaCO2. CLINICAL IMPLICATIONS: Method of oxytocin-induced parturition did not impact neonatal outcome. Interval from induction until parturition, degree of cervical dilatation, and intrapartum complications influenced induction success.     

Relation of umbilical vein cortisol to neonatal bilirubin concentrations

Umbilical vein (UV) plasma cortisol levels were assayed at delivery after spontaneous labour, oxytocin-induced labour, prostaglandin E2-induced labour and after delivery by elective Caesarean section. Higher mean UV cortisol levels were observed after vaginal delivery than after delivery by elective Caesarean section. The highest mean UV cortisol level was observed in the PGE2 group which accords with the known ability of prostaglandins to increase steroid production. The significance of these findings is discussed.