Effect of epidural analgesia on labor times and mode of delivery: a prospective study

PURPOSE

To assess changes in labor times and delivery outcome in low-risk women requesting pain relief and undergoing epidural analgesia, according to the epidural analgesia schemes.

MATERIALS AND METHODS

Prospective observational study of 499 low-risk women with epidural analgesia. Speed of dilatation (SD) (centimeters of dilatation / hours), speed of lowering of the fetal head through maternal pelvis (SL) (centimeters in lowering / hours), time of active phase of labor (TA), cesarean section (CS), vacuum application (VA) were dependent variables in multivariable linear and logistic regressions.

RESULTS

Dilution of ropivacain, fentanyl amount, and volume of the first dose of epidural analgesia did not seem to affect labor times. Epidural analgesia with schemes used in this study favored both the dilatation and the fetal head lowering through maternal pelvis. Every five minutes from the first dose of epidural to the last top-up, SD decreased by about 13% (p=0.002), SL decreased by about 14% (p<0.001), and TA increased by about 40% (p<0.001). Additionally, every five minutes from the first dose of epidural to the last top-up, the odds of an operative vaginal birth (vacuum) increased by 0.7% (p<0.001). Increasing of number of top-ups independently caused a reduction in odds of undergoing CS (odds ratio 0.434; C.I. 95% 0.219-0.859, p=0.017), without influencing labor times.

CONCLUSION

Epidural analgesia in patients requesting pain relief favors normal course of labor if it is not discontinued or delayed.

Does vaginal pH affect the efficacy of dinoprostone in cervical ripening/labor duration?

BACKGROUND

Prostaglandins are effective in the ripening of the cervix and facilitating labor induction. Vaginal pH is probably an important factor in the effectiveness of vaginal prostaglandins. The aim of this study was to evaluate the effect of vaginal pH on the function of prostaglandin vaginal tablet during labor.

METHODS

This is a double-blinded clinical trial study of 147 pregnant primigravid trated in the Yahyanejad Hospital of Babol (Iran) from January 2006 to December 2007. Initial pH was measured during vaginal examination with nitrazin paper and the Bishop score was determined. All women received vaginal dinoprostone inserted in the posterior fornix of the vagina for cervical ripening and the second dose was administered if the uterine contractions were inadequate. Reassessment of the Bishop score after 12 hours, duration of latent and active phases, and also the duration of the second stage of labor were compared between the two groups with low or high vaginal pH.

RESULTS

The incidence of Cesarean section was lower in women with high vaginal pH but was not statistically significant. The Bishop score after 12 hours, latent phase, and second stage durations were not different in the two groups of high or low vaginal pH, but active phase duration in patients with high pH was significantly shorter than those with low pH (p = 0.019).

CONCLUSION

High vaginal pH influences the function of prostaglandin tablet as a reduction in duration of the active phase of labor.

[Effects of 15 mcg intrathecal clonidine added to bupivacaine and sufentanil for labor analgesia]

BACKGROUND

For the combined spinal epidural analgesia for labour, 30 mcg of subarachnoid clonidine has proved its effectiveness to extend the analgesia, but increased severe hemodynamic effects.

AIM

To assess the effectiveness and the safety of 15 mcg intra thecal clonidine for labour analgesia.

METHODS

Four months, prospective, randomised, simple blind Study, including ASA I or II women, with mono foetal pregnancy. Patients were randomised in 2 groups: SB Group received intra thecal isobaric bupivacaine 2.5 mg and sufentanil 5 mcg and SBC Group received 15 mcg clonidine added to the same doses of bupivacaïne and sufentanil. Epidural analgesia was used when VAS is more than 30. Studied parameters were: delay of installation, duration of analgesia, VAS score, hemodynamic parameters and the incidence of maternal and neonatal side effects.

RESULTS

Sixty pregnant women were included (27 in SBC Group and 33 in SB group). The duration of initial analgesia was significantly longer in the SBC group (145 ± 43 min) compared with the SB group (98 ± 28 min). The delay of analgesia, sensory level and motor block level were similar. There was neither significant increase of the low incidence of blood pressure nor of the ephedrine consumption. The abnormalities of fetal heart rate, the mode of delivery and the incidence of side effects were also similar.

CONCLUSION

The addition of 15 mcg intra thecal clonidine to the bupivacaine and the sufentanil during combined spinal epidural analgesia for obstetrical labour results in extended significantly duration of analgesia without increasing side effects.

A novel optical method to assess cervical changes during pregnancy and use to evaluate the effects of progestins on term and preterm labor

OBJECTIVE

The purpose of this study was to determine whether optical methods can estimate cervix function during pregnancy and whether progestins modify this process.

STUDY DESIGN

Photos of the external cervix of timed-pregnant rats were taken every other day from day 13 until postpartum day 5 after daily treatments with vehicle (controls) or progestin treatments (progesterone, subcutaneously or vaginally; 17-alpha-hydroxyprogesterone caproate [17P] and RU-486 subcutaneously, once on day 16). The surface area of the cervix was estimated from photos.

RESULTS

The surface area of cervix increases throughout pregnancy and reverses after delivery in controls. In the progesterone subcutaneously or 17P subcutaneously groups, increases in surface area are lower (17P group until day 19 only; P < .05). Vaginal progesterone does not prevent surface area increases. Only the progesterone subcutaneously blocked delivery. RU-486 increases the surface area of the cervix (P < .05) during preterm delivery.

CONCLUSION

An optical method is useful for quantitative assessment of the cervix and evaluation of agents that modify cervical function.

Anti-inflammatory activity of oleanolic acid in rats and mice

Oleanolic acid displayed anti-inflammatory activity in carrageenan and dextran-induced oedema in rats. It elicited marked anti-arthritic action in adjuvant-induced polyarthritis in rats and mice and in formaldehyde-induced arthritis in rats. Oleanolic acid checked the inflammation-induced increased serum transaminase levels. It reduced exudate volume and inhibited leucocyte infiltration in carrageenan-induced pleurisy in rats. It is devoid of any analgesic, antipyretic or ulcerogenic action. Oleanolic acid did not affect the parturition time in pregnant rats or castor oil-induced diarrhoea in rats. Oral LD50 was found to be greater than 2 g kg−1 in mice and rats.

The Latent Phase of Labor: Diagnosis and Management

The latent phase of labor is complex and not completely understood by modern science. Studies often ignore evaluation of this phase of labor because determination of onset is subjective. In this article, the definition and time parameters of latent phase labor are discussed, and generalized distinctions between prelabor and labor are evaluated. Outpatient relief measures for latent phase as well as inpatient medical interventions for prolonged latent phase of labor are reviewed. Recommendations for policy development are included along with a discussion about the need to consider the significance of time limits. For optimal outcomes, clinicians are encouraged to individualize a management plan that is made in collaboration with the laboring woman.

A Review of Factors Associated With Dystocia and Cesarean Section in Nulliparous Women

The primary indication for cesarean section in nulliparous women continues to be clinical diagnoses that fall under the rubric of dystocia. These diagnoses account for approximately two-thirds of all cesareans experienced by otherwise healthy nulliparous women. Contemporary research evidence suggests that this clinical phenomenon is complex and multifactorial. This review explores factors associated with the phenomenon of dystocia in the context of a conceptual model that considers women's physical and psychological characteristics, fetal factors, intrapartum care and interventions, assessments and clinical decision-making of health care providers, the sociopolitical environment, and the social and physical environment of childbirth. Clinical recommendations include emphasis on the maintenance of normal weight and weight gain during pregnancy, delaying the admission of nulliparous women to the hospital until active labor is established, avoiding elective induction for nulliparous women, keeping women well-hydrated and well-fed during labor, providing high-quality supportive care during labor, staying the course with effective treatment when dystocia is encountered, and a renewed emphasis on the psychobehavioral preparation of nulliparous women for the realities of labor.

Comparison between amniotomy, oxytocin or both for augmentation of labor in prolonged latent phase: a randomized controlled trial

BACKGROUND

A prolonged latent phase is independently associated with an increased incidence of subsequent labor abnormalities. We aimed to compare between oxytocin augmentation, amniotomy and a combination of both on the duration of labor among women with a prolonged latent phase.

METHODS

Women with a singleton fetus in cephalic presentation who have a prolonged latent phase, were randomly allocated to amniotomy (group 1), oxytocin (group 2) or both (group 3). A group of women who progressed spontaneously without intervention composed the control group (group 4). The primary outcome was the duration of time from initiation of augmentation until delivery.

RESULTS

A total of 213 women were consented and randomized to group 1 (70 women), group 2 (72 women) and group 3 (71 women). Group 4 was composed from additional 70 women. A mean reduction of 120 minutes in labor duration was observed among group 3 compared to group 1 (p = 0.08) and 180 minutes compared to group 2 and 4 (p = 0.001). Women in group 3 had a shorter length of time from augmentation until the beginning of the active phase and a shorter first stage of labor than group 1 (p = 0.03), group 2 (p = 0.001) and group 4 (p = 0.001). Satisfaction was greater among group 3 and 4. Mode of delivery and neonatal outcome were comparable between the groups.

CONCLUSION

Labor augmentation by combined amniotomy and oxytocin among women with a prolonged latent phase at term seems superior compared to either of them alone.

[Efficacy and delivery outcomes of women underwent double-catheter epidural block during labor]

OBJECTIVE

To investigate the efficacy and pregnancy outcomes of women receiving double-catheter epidural block in labor analgesia, and compare the results with single-catheter epidural block.

METHODS

A double-blind clinical trial was conducted on 206 full-term singleton primiparas, aged 25 - 35 and at the 37 - 42 weeks of gestation who delivered at the Department of Obstetrics, Qingdao Municipal Hospital from August 2006 to December 2008, which were randomly divided into two groups: double-catheter epidural block (group D, n = 103) and single-catheter epidural-block (group S, n = 103). Women in group D were given mixture of 0.1% repivacaine hydrochloride and 0.5 mg/L sufentinil 4 - 6 ml as initial dose. Patient control epidural analgesia pump (PCEA) was connected with the upper catheter after 45 minutes. A bolus dose of 4 - 6 ml analgesia mixture was infused according to the condition through the lower catheter. Women in group S received analgesia mixture 10 - 15 ml as initial dose and PCEA pump was connected after 45 minutes. Oxytocin was infused in both groups according to uterine contraction after 30 minutes. The following indexes was observed: (1) visual analogue scales (VAS); (2)modified Bromage Scores; (3) the total dose of analgesia mixture, the percentage of oxytocin infusion, duration of labor and duration of the second stage of labor; (4) fetal birth weight and Apgar scores (1, 5 minutes); (5) mode of delivery; (6) the concentration of plasma cortisol and angiotension II at the beginning of regular uterine contraction and at the time when cervical dilated to 4 cm and 10 cm and fetal disengagement; (7) anesthesia-related complications.

RESULTS

(1) The neonatal birth weight and Apgar scores (1, 5 minutes) of group D were (3456 ± 468) g, 9.8 ± 0.6 and 9.9 ± 0.7, respectively, while (3399 ± 569) g, 9.8 ± 0.5 and 9.9 ± 0.7 in group S (P > 0.05). No motor function block was reported in any group and the modified Bromage score was zero. (2) The total dose of analgesia mixture in group D was similar to that in group S [(57 ± 9) ml vs. (58 ± 11) ml, P > 0.05]. However, the percentage of women received oxytocin in group D was smaller [59.2% (61/103) vs. 81.6% (84/103), P < 0.01], and the total time of labor and the duration of second stage of labor in group D were shorter [(532 ± 140) minutes vs. (608 ± 150) minutes; (46 ± 31) minutes vs. (60 ± 34) minutes, P < 0.05]. (3) There were no significant differences in VAS at 30 minutes after initial dose and in the first stage of labor between group D and S (1.2 ± 1.1 vs 1.2 ± 1.1, 1.1 ± 1.1 vs. 1.2 ± 1.0, P > 0.05). VAS at the second stage of labor stage was lower in group D than in group S (1.2 ± 1.1 vs. 4.5 ± 2.2, P < 0.01). (4) The rate of cesarean section, instrumental delivery and episiotomy in group D were lower than in group S (7.8% vs. 17.5%, 7.8% vs. 15.5%, 10.7% vs. 18.4%, P < 0.05). The incidence of fetal distress and meconium-stained amniotic fluid as the indication of cesarean section were similar between the two groups (P > 0.05). Lower incidence of fetal malpresentation and arrested second stage of labor were shown in group D than in group S (2.9% vs. 9.7%, 1.0% vs. 5.8%, P < 0.05). (5) The concentration of plasma cortisol and angiotension II were lower in group D than in group S [(86 ± 25) ng/L vs. (100 ± 20) ng/L, (278 ± 53) nmol/L vs. (311 ± 53) nmol/L, P < 0.05] only at the end of second stage of labor, but not at any other times (P > 0.05). (6) No serious anesthesia-related complications were reported in any groups. Some light backache around the puncture point were complained by 29.1% (30/103) of the women in group D and 31.1% (32/103) in group S (P > 0.05).

CONCLUSION

Double-catheter epidural block can provide better analgesia effect during labor than single-catheter epidural block, without any adverse influence on delivery outcomes.

Epidural analgesia with ropivacaine and sufentanil is associated with transient fetal heart rate changes

AIM

Fetal heart rate (FHR) changes have been reported after regional labor analgesia. In this prospective single-blinded study, we aimed to assess whether epidural analgesia with ropivacaine and sufentanil is associated with significant changes in fetal heart rate.

METHODS

Fetal heart rate traces from 120 women in active labor requesting epidural analgesia were recorded and analyzed by two reviewers 90 minutes before and after epidural analgesia for baseline fetal heart rate, accelerations, decelerations and long-term variability.

RESULTS

A significantly decreased number of fetal heart rate accelerations (ANOVA P=0.0001) and a higher percentage of segments with decelerations (P<0.05) were observed in the three segments after analgesia as compared to the three preceding segments. The minimum number of accelerations occurred during the 30 minutes immediately after analgesia was initiated. The reviewers were concordant in finding a significant change from the 60 minutes before to the 60 minutes after analgesia, a period in which there

CONCLUSION

Epidural analgesia with ropivacaine and sufentanil is associated with fetal heart rate changes. These modifications are transient and should be considered when evaluating fetal heart rate monitoring during labor to prevent inappropriate obstetric management decisions to proceed with operative labor.

Impact of the medicalization of labor on mode of delivery

AIMS

To evaluate whether routine medical interventions during labor (oxytocin augmentation, induction, amniotomy, epidural analgesia) condition the outcome of delivery independently of each other and of obstetric risk (calculated in an objective manner). Moreover, to evaluate whether there is an ideal window for initiating such interventions.

METHODS

Prospective, observational study with 1,047 patients enrolled.

RESULTS

Medical interventions were high, whether in low-, medium- or high-risk pregnancies. Oxytocin augmentation (odds ratio 4.678) labour induction (odds ratio 1.717) amniotomy (odds ratio 1.403) and obstetric risk (intermediate-risk odds ratio 1.889, high-risk odds ratio 2.008) increase the probability of an operative delivery. Oxytocin augmentation increases both the probability of a Cesarean delivery and vacuum extraction. Epidural analgesia reduces the probability of cesarean delivery and increases the probability of vacuum extraction. The greater the cervical dilation when oxytocin infusion is initiated, the lower the probability of an operative delivery. The more advanced the cervical dilation and the lower the station when amniotomy or epidural analgesia are carried out, the lower the probability of an operative delivery. Obstetric risk and oxytocin augmentation appear to increase the probability of operative delivery in patients who have undergone amniotomy or epidural analgesia. In addition, labor induction in patients who undergo epidural analgesia increases the risk of operative delivery.

CONCLUSIONS

Medical interventions during labor are high and cause a rise in operative delivery. Therefore, practitioners should defer it as much as possible. The exception is epidural analgesia because it seems to reduce the number of cesarean sections.

Detection of EETs and HETE-generating cytochrome P-450 enzymes and the effects of their metabolites on myometrial and vascular function

Cytochrome P-450 (CYP450) enzymes of the CYP2 and -4 family in humans metabolize arachidonic acid to generate bioactive epoxyeicosatrienenoic acids (EETs) and hydroxyeicosatetrenoic acids (HETEs). We report significantly higher levels of CYP 2J2 protein expression following the onset of labor (n = 6, P < 0.05), implying increased EET-generating capacity within the uterus. Myometrial relaxation to 8,9-EET and 5,6-EET was observed, with the latter being inhibited by preincubation with 1 muM paxilline and is supported by whole cell recordings showing a modest effect of 5,6-EET on myometrial outward-current density (n = 4, P < 0.05). Only 5,6-EET of the EETs tested affected vascular reactivity (n = 6). Both 12- and 20-HETE (n = 5-6) caused vasoconstriction of partially depolarized blood vessels, with glibenclamide (n = 5) enhancing the effect of 12-HETE alone. Our findings signify a role for CYP2C9/19, -2J2, and -4A11/22 in late pregnancy, possibly related to the synthesis of lipid metabolites and downstream effects on vascular remodeling in the term pregnant uterus. The presence of CYP4A11/22 and their resultant procontractile metabolites could argue either a role in the control and initiation of labor and/or modification of the vascular delivery system to influence blood flow to the laboring uterus. The differential effects of the EETs and HETEs in the pregnant human uterus identify the CYP pathway as a novel modulator of myometrial and vascular physiology during late pregnancy.

[Obstetric outcomes in oxytocin-related and spontaneous deliveries--analysis of 2198 cases]

AIM

The aim of the work was to compare labour courses, ways of delivery, condition of the newborns in spontaneous and oxytocin-related labours and to analyse the indications for oxytocin administration.

MATERIAL AND METHODS

2198 full-term deliveries (pregnant women qualified for elective caesarean section were excluded from the study) at the Provincial Hospital in Przemyśl, Poland.

STUDY GROUP

Labours with the adjunctive oxytocin infusion--1102 women.

CONTROL GROUP

spontaneous labours (without oxytocin administration)--1096 women. The analysis of the compatibility of measured traits was carried out by the Chi2 test, p < 0.05 was assumed as statistically significant level.

RESULTS

I. Indications for the oxytocin administration: secondary hypokinetic contractions of the uterus (642 labours--58.25%), premature rupture of membranes (176 labours - 15.97 %). II. Deliveries by caesarean section: 1. study group--187 women (16.97%). 2. control group--97 women (8.85%). Ch2 = 32.192; df = 1; p = 0.0000. III. Newborns after vaginal labours scored 7 or below according to the Apgar in the first minute after the delivery. 1. study group--35 newborns (8.7%); 2. control group--18 newborns (1.8%) ch2 = 5.493; df = 1; p = 0.0190. IV. Newborns hospitalised for over 48 hours: 1. study group--346 (31.39%); 2. control group--216 newborns (19.70%). Chi2 = 39.454; df = 1; p = 0.0000.

CONCLUSIONS

(1) Hypokinetic uterine contractions were the most frequent indication for oxytocin administration during labour. (2) Oxytocin administration increases twice the risk of delivery by the caesarean section. (3) Newborns after vaginal oxytocin-related labours scored 7 or below on the Apgar score in the first minute after the birth when compared to the newborns after spontaneous labour. (4) Oxytocin administration during parturition elongates the time of newborns hospitalisation.

A randomized, double-blinded, controlled trial comparing parenteral normal saline with and without dextrose on the course of labor in nulliparas

OBJECTIVE

The objective of the study was to compare intravenous normal saline with and without dextrose on the course of labor in nulliparae.

STUDY DESIGN

In a double-blinded, controlled trial, term, nulliparae with singletons in active labor were randomized into 1 of 3 groups receiving either normal saline (NS), NS with 5% dextrose (D5NS), or NS with 10% dextrose (D10NS) at 125 mL/h. The primary outcome was total length of labor from onset of study fluid in vaginally delivered subjects. Maternal and neonatal outcomes were also analyzed.

RESULTS

Of 300 subjects enrolled, 289 met inclusion criteria and completed the study. In vaginally delivered subjects, significant differences were noted in the second stage (P = .01) and total length of labor (P = .02). No significant differences were observed in the cesarean section rates between the groups (P = .21). No differences were noted in maternal or neonatal secondary outcomes.

CONCLUSION

Administration of a dextrose solution, regardless of concentration, was associated with a shortened labor course in term vaginally delivered nulliparae subjects in active labor.

Hemodynamic changes during vaginal delivery in a parturient with no labor pain

This is the case of a 35-year-old woman who had an induction for vaginal delivery because of severe pre-eclampsia. This case demonstrates the hemodynamic changes during the second stage of labor in a patient with epidural analgesia and complete pain relief during delivery.

Endocrine and pharmacological factors which influence the onset of labour in rhesus monkeys

Indomethacin administration in late pregnancy prolonged gestation in caged rhesus monkeys and inhibited premature labour and postponed delivery in chronically catheterized monkey fetuses. Chronic indomethacin treatment was associated with a reduction in the urinary excretion of a prostaglandin metabolite, a potent inhibitory effect on myometrial cyclic AMP phosphodiesterase, and severe oligohydramnios in pre-term and post-term fetuses. Experimental anencephaly (functional hypophysectomy) of the rhesus fetus results in lowered concentrations of maternal oestradiol and loss of the precise control of gestational length, with 40% of fetuses delivering beyond term. Corticotropin (ACTH) infused into the fetus results in raised concentrations of fetal and maternal cortisol, progesterone and oestrogens. Progesterone concentrations in peripheral blood apparently have little bearing on uterine quiescence in the rhesus monkey, since the concentrations of progesterone in maternal and fetal blood vary directly with uterine activity. The results of chronic infusion of corticotropin in the fetal monkey support the theory that in the monkey parturition is mediated by increased oestrogen production by the fetoplacental unit and by a rise in the concentrations of oestrone and prostaglandin in the amniotic fluid.

Fetal cortisol and the initiation of labour in the human

The role of the fetal adrenal activity in the initiation of parturition in the human has been investigated. Women were studied in the last trimester of pregnancy during treatment with betamethasone for prevention of the idiopathic respiratory distress syndrome. Although betamethasone caused a considerable drop in the cortisol concentrations of fetal plasma and amniotic fluid, the time to spontaneous delivery in this group was similar to that in matched controls. Moreover, cortisol in fetal scalp blood at the onset of parturition in untreated women did not differ between those with spontaneous and those with induced labour. Evidence is given that increase of circulating cortisol in the fetus during the course of parturition predominantly reflects a rise in maternal cortisol under the influence of labour. The strain of labour seems to partly override the betamethasone-induced inhibition of maternal cortisol release. The possible ability of the fetal adrenals to respond to stimuli is illustrated by comparison of cortisol concentrations in cord plasma after various forms of complicated deliveries.

The role of prostaglandins in parturition, with special reference to the rat

The evidence which suggests a role for prostaglandins in parturition is reviewed, with special reference to experimental observations on the rat. The pregnant uterus can both synthesize and metabolize prostaglandins. The biosynthetic capacity of the rat uterus increases as pregnancy proceeds. This increase, which is especially marked during the last few days of pregnancy, may be oestrogen-controlled. During pregnancy the tissue levels of the major prostaglandin-metabolizing enzyme, 15-hydroxyprostaglandin dehydrogenase (EC 1.1.1.141) is greatly increased. This may prevent aberrant production of prostaglandins from terminating the pregnancy prematurely. The capacity for prostaglandin metabolism begins to fall (perhaps under hormonal control) as the expected day of delivery approaches; this, coupled with an augmented biosynthesis, produces a net increase in uterine prostaglandins which contribute to the process of parturition by causing a decrease in progesterone concentration, increasing the muscular tone of the uterus, and altering uterine haemodynamics. Agents which block either prostaglandin synthesis or metabolism delay or accelerate the parturition process in the rat.

Pharmacokinetics of oral zidovudine administered during labour: a preliminary study

OBJECTIVES

The aim of this study was to determine whether oral zidovudine (ZDV) given during labour would provide a similar systemic exposure to the established intravenous regimen used to prevent mother-to-child transmission in HIV-infected pregnant women.

METHODS

ZDV pharmacokinetic parameters following oral administration during labour were determined in 10 HIV-infected pregnant women in active labour. All subjects were converted to intravenous ZDV prior to delivery.

RESULTS

In cohort 1 (n=6), subjects received 300 mg oral ZDV every 3 h for three doses. Oral therapy was well tolerated but plasma ZDV concentrations were substantially lower than previously reported with continuous intravenous therapy. Based on the pharmacokinetic results from cohort 1, women in cohort 2 (n=4) received an initial 600 mg dose followed by two 400 mg doses every 3 h. ZDV area under the curve and concentrations in cohort 2 increased approximately in proportion to the increase in dose but varied 6-7-fold. In both cohorts, ZDV pharmacokinetic parameters suggested erratic absorption.

CONCLUSIONS

While ZDV exposure improved with the increased dosing regimen, our sample size was small and larger studies are needed to establish whether oral ZDV administration during labour can consistently provide equivalent exposure to intravenous administration.

Infusion of oxytocin induces successful delivery in prostanoid FP-receptor-deficient mice

The dramatic increase of oxytocin (OT) receptor (OTR) in the myometrium as well as circulating progesterone withdrawal has been thought to be the most important factor in the induction and accomplishment of parturition since delivery fails in prostaglandin F2alpha receptor (FP) knockout (FP KO) mice. The expression levels of OTR mRNA/protein were not dramatically increased in the near-term uteri of FP KO mice. However, OT-induced myometrial contractions and the concentration-response curves in FP KO in vitro were almost similar to those in wild-type (WT) mice. OT-infusion (0.3 U/day) enabled FP KO mice to experience successful delivery, and furthermore the duration until the onset was hastened by a higher dose of OT (3 U/day). The plasma progesterone levels of FP KO females were maintained at high levels, but decreased during labor by OT-infusion (3 U/day). These results suggest that OT has potentials to induce strong myometrial contractions in uterus with low expression levels of OTR and luteolysis in ovary, which enabled FP KO females to undergo successful delivery.

Contractility and calcium signaling of human myometrium are profoundly affected by cholesterol manipulation: implications for labor?

The authors elucidate cholesterol's effect on human uterine contractility and calcium signaling to test the hypotheses that elevation of cholesterol decreases uterine activity and that oxytocin cannot augment contraction when cholesterol is elevated. The effects of cholesterol extraction with methyl beta-cyclodextrin and enrichment with low-density lipoproteins and cholesterol on contractile activity and intracellular calcium signaling in spontaneous or oxytocin-stimulated myometrium are determined. Force occurring spontaneously and with oxytocin is significantly increased by cholesterol extraction. Cholesterol enrichment profoundly inhibits force production in a dose-dependent manner and could reverse the effects of cholesterol extraction. Qualitatively similar results are found for nonpregnant and pregnant laboring and non-laboring myometrium. These contractile changes are related to changes in intracellular Ca2+ . Thus, elevated cholesterol is deleterious to contractility and Ca2+ signaling in human myometrium. Cholesterol may contribute to uterine quiescence but could cause difficulties in labor in obese/dyslipidemic women, consistent with their increased cesarean delivery rates.

[Transient neurological symptoms in puerperas after epidural analgesia during labor]

The investigation was undertaken to elucidate the impact of epidural analgesia (EA) during labor on the incidence of transient neurological symptoms (TNS). By the agreement of a local ethics committee, an informed consent was obtained from 90 healthy puerperas enrolled in the investigation. The patients were randomized into 3 groups, with 30 patients in each. At the beginning of labor, an epidural catheter was inserted in all the puerperas. For EA, 1% lidocaine solution and 0.2% ropivacaine solution were used in Groups 1 and 2, respectively; Group 3 was control in which EA was not performed. Two days after labor, an independent observer asked the females about possible neurological symptoms, by using the standard questionnaire. TNS included symmetric pain and/or dysesthesia in the buttocks, lower lumbar region, and/or legs. The patients who presented problems were proposed to indicate the degree of discomfort by a 10-score verbal scale. The findings were statistically processed using the U-test and X-test (p < 0. 05). A total of TNS occurred in 22 (25%) patients, including 7 (27%), 8 (27%), and 7 (23%) in Groups 1, 2, and 3, respectively. This difference was not statistically significant. The duration of TNS was generally short; in all the patients, the symptoms were completely resolved after 24-72 hours. Labor EA is not a cause of TNS. The type of a local anesthetic (lidocaine, ropivacaine) does not affect the incidence of TNS in puerperas after labor EA.

Medical potential of plants used by the Q'eqchi Maya of Livingston, Guatemala for the treatment of women's health complaints

Investigation on the medical ethnobotany of the Q'eqchi Maya of Livingston, Izabal, Guatemala, was undertaken in order to explore Q'eqchi perceptions, attitudes, and treatment choices related to women's health. Through participant observation and interviews a total of 48 medicinal plants used to treat conditions related to pregnancy, childbirth, menstruation, and menopause were collected and identified followed by the evaluation of 20 species in bioassays relevant to women's health. Results of field interviews indicate that Q'eqchi cultural perceptions affect women's health experiences while laboratory results (estrogen receptor and serotonin receptor binding assays) provide a scientific correlation between empirical medicinal plant use among the Q'eqchi and the pharmacological basis for their administration. These data can contribute to Guatemala's national effort to promote a complementary relationship between traditional Maya medicine and public health services and can serve as a basis for further pharmacology and phytochemistry on Q'eqchi medicinal plants for the treatment of women's health conditions.

Determination of the ED95 for intrathecal plain bupivacaine combined with fentanyl in active labor

BACKGROUND

Combined spinal-epidural (CSE) analgesia is an effective technique for pain control in labor and is particularly useful in the active phase. Excessive doses of intrathecal bupivacaine may be associated with adverse effects. This study is designed to estimate the ED95 for intrathecal plain bupivacaine with fentanyl 15 microg in labor.

METHODS

Forty healthy women in active labor (cervical dilatation > or = 5 cm and verbal numeric pain score > or = 6/10) were given CSE for labor analgesia with intrathecal plain bupivacaine and fentanyl 15 microg. The initial dose of bupivacaine was 1.75 mg. Doses were varied in a 0.25-mg testing interval according to a method of sequential allocation designed to cluster the dose around the ED95. Effectiveness was defined as a verbal numeric pain score < or = 1 within 10 min of intrathecal injection.

RESULTS

There was a 100% response rate to the 1.75-mg dose (95% CI 84.6-100.0%) and an 85.0% response rate to 1.50 mg (95% CI 64.0-95.8%). The ED95 for intrathecal plain bupivacaine with fentanyl 15 microg in active labor was 1.66 mg (95% CI 1.50-482.5 mg). The incidence of fetal bradycardia was 7.5%. The incidence of pruritus was 55%. No patient experienced motor block.

CONCLUSIONS

This is the first dose-finding study specifically designed to estimate the ED95 of intrathecal bupivacaine combined with a fixed amount of fentanyl for analgesia in active labor. The combination of bupivacaine 1.75 mg with fentanyl 15 microg rapidly and reliably alleviated pain in the active phase of labor.

Epidural clonidine added to a bupivacaine infusion increases analgesic duration in labor without adverse maternal or fetal effects

PURPOSE

Many obstetric patients receiving epidural analgesia are encouraged to ambulate. This current study was designed to determine the potential for maximizing the time to first epidural supplement when adding clonidine to a 0.625 mg.ml(-1) bupivacaine continuous epidural infusion following epidural fentanyl bolus in early labor for patients allowed to ambulate. Maternal and fetal effects secondary to clonidine were also evaluated.

METHODS

Sixty-eight laboring primigravid women received a 3-ml epidural test dose of lidocaine with epinephrine, followed by a fentanyl 100-microg bolus (in a 10 ml-volume). The patients then received a 0.625 mg.ml(-1) bupivacaine continuous epidural infusion, either with or without clonidine (5 microg.ml(-1)), at a rate of 10 ml.h(-1). Pain scores and side effects were recorded for each patient.

RESULTS

The overall quality of analgesia was similar in both groups. The mean duration prior to request for additional analgesia was significantly longer in the clonidine group (269 +/- 160 min), compared to the control group (164 +/- 64 min). No patient in either group experienced any detectable motor block; one patient (clonidine group) complained of mild thigh numbness and was not allowed to ambulate. While mean blood pressure was approximately 6 mmHg lower in the clonidine group at 1, 1.5, and 3.5 h, this was not clinically significant. No adverse effects on maternal heart rate or fetal heart rate were noted.

CONCLUSION

In early laboring patients, addition of clonidine prolongs the analgesia duration of a 0.625 mg.ml(-1) bupivacaine continuous epidural infusion following 100 microg epidural fentanyl (after a lidocaine-epinephrine test dose) without a clinically significant increase in side effects.

A novel tocolytic agent: effects of letrozole on gestational length and parturition time

The purpose of this study was to determine whether letrozole, a potent aromatase inhibitor, could prolong gestation and/or delay parturition in rats. Seventy-five rats were divided into five groups of 15 rats each. Group I and group II rats were administered letrozole orally at doses of 0.002 and 0.02 mg/kg/day from days 15 through 21 of pregnancy, respectively. Rats in group IA were administered a concomitant estradiol cyclopentylpropionate (ECP) injection on day 15 and 0.002 mg/kg letrozole in that same manner as for group I. Rats in group IIA were administered concomitant ECP on day 15 and 0.02 mg/kg letrozole in the same manner as for group II. The control group received sterile saline only. Study and control groups were compared with respect to gestational length, parturition time, fetal mortality rate, stillbirth rate, and fetal body weight. Oral administration of letrozole both at daily doses of 0.002 mg/kg/day (group I) and 0.02 mg/kg/day (group II) consistently prolonged gestation and parturition time. The values of stillbirth rate, fetal mortality rate, and fetal body weight of group I were similar to those in the control group; conversely, fetal mortality rate and stillbirth rate of group II were higher than those values in the control group, and fetal body weight of group II was lower than in the control group. It was observed that concomitant injection of ECP effectively reversed the deleterious effects of letrozole on gestational length, parturition time, fetal mortality rate, stillbirth rate, and fetal body weight. The results of this study indicate that the aromatase inhibitor letrozole can prolong gestation and delays parturition in rats. Its deleterious effects on parturition can be reversed by ECP injection.

EMG activity of the muscular and stromal layer of the cervix in relation to EMG activity of the myometrium and cervical dilatation in PGF2α induced parturition in the cow

The goal of this study was to quantify and characterize the electromyographic (EMG) activities in the cervical outer muscular layer and in the cervical stromal layer, and to characterize their relationship with myometrial EMG activity and cervical dilatation during PGF2alpha-induced parturition in term pregnant cows. We continuously measured the EMG activity of the uterine myometrium and cervical outer muscular layer as well as the cervical stromal layer in five cows using bipolar electrodes while at the same time measuring changes in the cervical diameter with ultrasound cervimetry. This we did from the moment a prostaglandin analogue was injected until the expulsion of the calf. In contrast to the cervical stromal layer, the cervical outer muscular layer showed distinct EMG activity, which began to increase at about the same time as the EMG activity of the myometrium, i.e. some 12 h before the start of cervical dilatation. However, the rate of this increase was lower than in the myometrium and it was not characterized, like in the myometrium, by an increase in maximum EMG amplitude. Although the cervical outer muscular layer showed contracture and contraction like EMG activity in unison with in the myometrium, it was also characterized by a more irregular EMG activity, which occurred independently from the myometrium. These data suggest that while the outer muscular layer of the cervix may be considered to be a caudal continuation of the myometrium, it also displays activity independently from the myometrium. The physiological relevance of this activity remains to be explored.

The effect of dose and route of administration of R-cloprostenol on the parturient response of sows

The aims of the present study were to further examine the efficacy of different doses and routes of R-cloprostenol administration on the parturition response in sows. Fifty crossbred multiparous sows (Landrace x Yorkshire) with an average parity number of 4.7 +/- 2.4 were allocated to induce farrowing by one of the following treatments: Group I (control, n = 10) injection with normal saline 2 ml administered intramuscularly (i.m.); Group II (n = 10) injection with 75 microg of R-cloprostenol administered i.m. (at 7 AM); Group III (n = 10) injection with 75 microg of R-cloprostenol (at 7 AM) together with 10 IU of oxytocin (24 h after injection of R-cloprostenol) administered i.m.; Group IV (n = 10) injection with 37.5 microg of R-cloprostenol (at 7 AM) administered into perivulva region; Group V (n = 10) injection with 37.5 microg of R-cloprostenol (at 7 AM) administered into perivulva region together with 10 IU of oxytocin (24 h after injection of R-cloprostenol) administered i.m. The following parameters: pre-farrowing maternal behaviour, restless behaviour, R-cloprostenol or oxytocin injection to farrowing interval, expulsion intervals, duration of farrowing, total number of piglets born, litter birthweight, umbilical cord morphology and the degree of meconium staining were record. There were no significant differences among groups for the pre-farrowing maternal behaviours. In all the sows, the restless behaviour was not observed. There were no significant effect of oxytocin administration (10 IU, i.m.) on the percentage of umbilical cord morphology and the degree of meconium staining in different groups. There were no significant effect of route and dose of administration on the number of total piglet born, piglet born alive, stillbirth, mummy and litter birthweight. No significant effects of the different groups were found on the R-cloprostenol and oxytocin injection to farrowing interval, expulsion interval and farrowing duration. In conclusion, the present results demonstrated that a half dose (37.5 microg) of R-cloprostenol administered into the perivulva region was effective for inducing farrowing as the full recommended dose (75 microg) administered into the neck region (i.m.) and with no restless behaviour.

A Comparison of Minimum Local Anesthetic Volumes and Doses of Epidural Bupivacaine (0.125% w/v and 0.25% w/v) for Analgesia in Labor

BACKGROUND

In this study we sought to determine and compare the minimum local anesthetic volumes (MLAV) and doses (MLAD) of two concentrations of bupivacaine for epidural pain relief in labor, and to quantify the effect on dose.

METHODS

Eighty women were randomized in a double-blind manner to receive a first bolus of either plain bupivacaine 0.125% (w/v) or 0.25% (w/v). The arbitrary starting volume was 15 mL. Subsequent volumes were decided by sequential allocation according to analgesic efficacy. A visual analog pain score < or =10 (0-100) within 30 min, indicated effective analgesia. The next woman received a decrement of 2 mL. A failure of the visual analog pain score to reach < or =10 was followed by a 2 mL increment for the next woman.

RESULTS

Using the formula of Dixon and Massey, MLAV and MLAD, with 95% confidence intervals (CI) were calculated for each concentration. MLAV was 13.6 mL (95% CI 12.4-14.8), with bupivacaine 0.125% (w/v), and 9.2 mL (95% CI 6.9-11.5) with bupivacaine 0.25% (w/v). The difference was highly significant (P = 0.002). MLAD for these volumes were 17.0 mg (95% CI 15.5-18.5), and 23.1 mg (17.2-28.9), respectively (P = 0.045).

CONCLUSIONS

Bupivacaine 0.125% (w/v) when compared with 0.25% (w/v) produced equivalent analgesia with a 50% increase in volume, but with a 25% reduction in dose. Any reduction in dose, without loss of efficacy, reduces risk of toxicity and improves safety.

Combined spinal epidural analgesia for labor with and without 3 ml of 1.5% epidural lidocaine

BACKGROUND

Lidocaine is used as a 'test dose' to detect misplacement of epidural catheters. When administered immediately after the initiation of a combined spinal epidural for labor analgesia, it was found to interfere with motor function. The authors hypothesized that an epidural test dose of 3 ml of 1.5% lidocaine injected immediately after the initiation of combined spinal epidural analgesia and followed by a continuous epidural infusion would prolong the duration of analgesia and decrease the incidence of breakthrough pain.

MATERIAL/METHODS

Sixty nulliparous parturients were recruited for this randomized controlled trial. Combined spinal epidural analgesia was performed with intrathecal levobupivacaine 2.5 mg and fentanyl 25 microg. The patients were randomized into three groups: group L receiving 3 ml of 1.5% epidural lidocaine, group S 3 ml of normal saline, and group C the control group receiving no test solution. An epidural infusion of 0.1% levobupivacaine and 2 microg of fentanyl/ml at 10 ml/hr was initiated immediately. Their need for supplementary analgesia, duration of analgesia, sensory block, motor block, side-effects, and overall satisfaction were recorded.

RESULTS

The breakthrough pain rate in all groups were similar. Their mean duration of analgesia (mean survival times) were not significantly different. Group C had the lowest incidence of lower limb motor block. The satisfaction scores were significantly highest in group L.

CONCLUSIONS

The administration of epidural lidocaine and saline immediately after intrathecal levobupivacaine 2.5 mg and fentanyl 25 microg did not reduce the incidence of breakthrough pain in combined spinal epidural labor.

Newborn skin temperature two days postpartum during breastfeeding related to different labour ward practices

AIM

To investigate (1) the skin temperature pattern in newborns two days after birth in connection to breastfeeding and to examine (2) if the administration of epidural analgesia (EDA) and oxytocin (OT) infusion during labour influences this parameter at this point of time.

METHOD

Forty-seven mother-infant pairs were included in the study: nine mothers had received OT stimulation during labour (OT group), 20 mothers had received an EDA and OT during labour (EDA group), while 18 mothers had received neither EDA nor OT stimulation during labour (control group). A skin temperature electrode was attached between the newborn's shoulder blades. The newborn was placed skin-to-skin on the mother's chest and covered with a blanket. The temperature was recorded immediately after the newborn was put on the mother's chest and at 5, 10, 20 and 30 min.

RESULTS

The temperature measured when the newborns were put skin-to-skin on their mothers' chest was significantly higher in the infants of the EDA group (35.07 degrees C) when compared to the control group (34.19 degrees C, p=0.025). Skin temperature increased significantly (p=0.001) during the entire experimental period in the infants belonging to the control group. The same response was observed in infants whose mothers received OT intravenously during labour (p=0.008). No such rise was observed in infants whose mothers were given an EDA during labour.

CONCLUSION

The results show that the skin temperature in newborns rises when newborns are put skin-to-skin to breastfeed two days postpartum. This effect on temperature may be hampered by medical interventions during labour such as EDA.

Hemodynamic stability during labor and delivery with continuous epidural infusion

CONTEXT

Epidural anesthesia for labor pain is frequently complicated by maternal hypotension.

OBJECTIVE

To test whether continuous epidural infusion (CEI) of local anesthetic, without bolus administration, lowers the incidence of hypotension in parturient patients.

METHODS

In a single-blind clinical study, subjects were randomly assigned to CEI-only (10 mL/h of 0.2% ropivacaine hydrochloride without bolus) or control (10 mL of 0.2% ropivacaine hydrochloride per hour with 10-mL bolus) epidural dosing groups. The incidence of hypotension (20% decrease in systolic blood pressure or mean arterial pressure (MAP), systolic blood pressure lower than 100 mm Hg, or MAP lower than 65 mm Hg) was recorded for 2 hours after dosing. Statistical analysis included a 2x2 chi(2) analysis, the Fisher exact test, and paired two-tailed t tests.

RESULTS

Fifty subjects were studied, with 25 randomly assigned to each study group (CEI-only vs control). Baseline blood pressure was not different between groups (CEI-only, 127 [11]/77 [8.7] mm Hg; control, 131 [14]/78 [2]). The incidence of hypotension was lower in the CEI-only group than in the control group (5 [20%] vs 15 [60%]; P=.009), with intervention required in 1 (20%) of 5 CEI-only subjects and 7 (47%) of 15 control subjects. Sensory block reached the T10 dermatome in 54.4 (18) minutes in the CEI-only group and 38 (24) minutes in the control group (P=.04). Pain scores and maternal and fetal pulse rates were not different between groups. Analgesic supplementation (250 microg of epidural fentanyl) was used more frequently in the CEI-only group (72% vs 32%; P=.01), without adverse effects.

CONCLUSIONS

Continuous epidural infusion of 0.2% ropivacaine hydrochloride without bolus administration reduces the incidence of hypotension by 67% and is safer than traditional bolus dosing for routine labor. This method requires further study in high-risk patients, including those with preeclampsia and cardiovascular disease.

Clinical triggers to initiate intrapartum penicillin therapy for prevention of group B streptococcus infection

Despite national recommendations for prophylactic group B streptococci intrapartum penicillin therapy (GBS-IPT), there is little guidance for clinicians regarding to how to achieve the recommended 4 hours of therapy. We sought to identify clinical triggers for effective temporal prompts to initiate GBS-IPT to achieve the recommended duration of therapy. GBS-colonized women who delivered between 37 and 42 weeks were analyzed retrospectively. The clinical record was reviewed for clinical events including rupture of membranes, oxytocin therapy, 4-cm dilation, active labor, narcotic analgesia, epidural analgesia. In addition, combinations of these triggers were evaluated using the first appearance of 4-cm dilation or active labor, narcotic analgesia or epidural, and a composite indicator of each of these four triggers. Antibiotic duration and proportion receiving 4 hours of GBS-IPT for each trigger were compared with the conventional penicillin management the patient actually received (CM). Data were analyzed with Z-test for proportions with Bonferroni correction and one-way analysis of variance. Two hundred thirteen women met study criteria and were reviewed. Using CM, 90.8% of nulliparas and 68.7% of parous women achieved adequate GBS-IPT. In nulliparas, each clinical trigger resulted in equivalent rates of adequate GBS-IPT compared with CM. The duration of therapy was less for 4-cm dilation, epidural, epidural or narcotic analgesia, and 4-cm dilation or active labor triggers in nulliparas, suggesting better identification of the period 4 hours prior to delivery. In parous women, clinical triggers did not perform better than CM. In nulliparous women, clinical triggers to initiate therapy may achieve high rates of GBS-IPT, with a significant decrease in the duration of antibiotic therapy. In nulliparous women, clinical triggers better identify the 4-hour window prior to delivery than CM.

Controlled-Release Misoprostol Vaginal Insert in Parous Women for Labor Induction

OBJECTIVE

To assess the ability of a controlled-release misoprostol vaginal insert to induce labor using dose reservoirs of 25, 50, 100, and 200 microg.

METHODS

This double-blind, dose ranging, randomized study was carried out in parous women requiring induction of labor at term. Each woman was randomly assigned to receive a single misoprostol vaginal insert that could remain in place for up to 24 hours and was removed for onset of active labor, an adverse event, or having reached 24 hours in situ. The primary outcome measure was time from insertion of the misoprostol vaginal insert to vaginal delivery of the neonate.

RESULTS

A total of 124 women participated in the study. The median time to vaginal delivery was 27.5, 19.1, 13.1, and 10.6 hours for the 25-, 50-, 100-, and 200-microg doses, respectively. The percentage of women who delivered vaginally within 12 hours was 9%, 14%, 47%, and 53% (P<.001 using the 25-microg group as the comparator) and within 24 hours was 42%, 79%, 81%, and 70% (P=.003). Uterine hyperstimulation syndrome occurred in one woman who received the 25-mug, two women who received the 100-microg, and three women who received the 200-microg dose reservoirs.

CONCLUSION

Misoprostol vaginal inserts effectively induced labor in pregnant parous women at term.

LEVEL OF EVIDENCE

I.

Outcome in obstetric care related to oxytocin use. A population-based study

BACKGROUND

The purpose of this study was to investigate the delivery outcome in relation to oxytocin use in labor.

METHODS

We studied 106,755 deliveries from 1995 to 2002 in the Perinatal Revision South, a population-based register comprising information from 10 hospitals in southern Sweden.

RESULTS

Oxytocin use in labor increased from 27.6% in 1995/96 to 33.2% in 2001/02 (p<0.000006). Oxytocin was administered to 47.7% of the nulliparas and 18.5% of the multiparas. There were large differences between hospitals (range among nulliparas: 32.6-60.4%; among multiparas: 13.9-27.0%). After exclusion of deliveries with induction of labor and deliveries lasting >12 h, there was a significant association between oxytocin use and Apgar score < 7 at 5 min (OR 2.3; 95% CI 1.8-2.9), need for neonatal intensive care (OR 1.6; 95% CI 1.5-1.7), and operative delivery (OR 4.0; 95% CI 3.7-4.2).

CONCLUSIONS

In deliveries with relatively short duration (< or =12 h), a significant association was seen between oxytocin use and adverse outcome. Even though the results are difficult to interpret, the significant difference between the use of oxytocin in different hospitals, as well as the increase of oxytocin use over time, calls for a randomized controlled study to elucidate the advantages and disadvantages of oxytocin use during labor and delivery.

Barusiban, an effective long-term treatment of oxytocin-induced preterm labor in nonhuman primates

Preterm labor (PTL) affects up to 25% of human pregnancies in developing countries, but there are few therapeutic options. Based on the key role of oxytocin (OXT) in labor and parturition, OXT antagonists are a potentially useful class of drugs for PTL. Barusiban is a new selective, potent, and long-acting OXT receptor antagonist. In this study barusiban was given by continuous i.v. infusion to monkeys during the last 3 wk of pregnancy; the monkeys were also given daily doses of OXT to induce uterine contractions and simulate PTL. Barusiban effectively suppressed OXT-induced PTL-like contractions and prevented early delivery. In contrast, fenoterol (a beta2-adrenoceptor [beta2-AR] agonist used as a comparative control) did not inhibit uterine contractions in this model. Barusiban was particularly effective in maintaining low intrauterine pressure (IUP) near the end of pregnancy, which is when IUP in both OXT controls and fenoterol-treated females increased substantially. Although barusiban delayed the onset of labor, it did not prevent normal delivery. These data demonstrate the safety and efficacy of barusiban in reducing uterine contractility in response to repeated OXT challenge, and suggest that barusiban may be therapeutically effective in long-term treatment of PTL.

Evaluation of the effect of castor oil on initiating labor in term pregnancy

OBJECTIVE

To determine the effect of castor oil on initiating labor in term pregnant women.

METHODS

We conducted this randomized control clinical trial on 47 pregnant women from August 2003 to March 2004 in Mashhad University of Medical Sciences, Iran.

RESULTS

There was a significant increase in labor initiation ratio in the castor oil group compared with the control group (54.2% compared with 4.3%, p<0.001). Also, the mean bishop score in the castor oil group increased from 2.50 +/- 1.29 to 6.79 +/- 3.20 (p<0.001).

CONCLUSION

The probability of labor initiation increases during the first 24 hours after using castor oil, however, further studies are recommended to improve its efficacy and safety.

The use of neuraxial adjuvant drugs (neostigmine, clonidine) in obstetrics

PURPOSE OF REVIEW

Neuraxial adjuvant drugs are used to improve analgesia and to decrease complications associated with a high dose of a single drug. Opioids are used in routinely, but alpha2-agonists, such as clonidine or cholinesterase inhibitors (neostigmine), have also been used for labour analgesia or to relieve pain following caesarean section. Both drugs possess a common mechanism of action that can be beneficial.

RECENT FINDINGS

Small doses of intrathecal clonidine (30 microg), combined with local anaesthetics and opioids, prolong labour analgesia. Hypotension can occur and must be promptly treated by ephedrine to avoid fetal side effects. Epidural clonidine (60 to 75 microg) produces prolonged analgesia from local anaesthetics and opioids and allows a ropivacaine sparing effect. Intrathecal neostigmine has analgesic properties, but its gastro-intestinal side effects contraindicate its clinical use. Epidural neostigmine, combined with sufentanil or clonidine, initiates labour analgesia (minimum 6 to 7 microg/kg; 500 microg) without side effects, however, and allows a 'mobile epidural'. Epidural and spinal clonidine can be used to improve postcaesarean section analgesia. Epidural neostigmine at the doses studied produces modest analgesia following caesarean section.

SUMMARY

Co-administration of neuraxial drugs may enhance analgesia and reduce the side effects of each drug. Clonidine and neostigmine may be used in obstetrics, under some conditions.

General obstetrics: Fish oil in various doses or flax oil in pregnancy and timing of spontaneous delivery: a randomised controlled trial

OBJECTIVES

To test the earlier suggested hypothesis that intake of long-chain n-3 fatty acids from fish oil may delay the timing of spontaneous delivery and to test if alpha-linolenic acid, provided as flax oil capsules, shows the same effect.

DESIGN

Randomised controlled trial including women reporting low dietary fish intake. The women were allocated in the proportions of 1:1:1:1:1:1:2 into six treatment groups and a control group, respectively, from week 17-27 of gestation. The treatment groups received fish oil, in various doses, or flax oil, and the control group did not receive any treatment.

SETTING

The Danish National Birth Cohort.

SAMPLE

A total of 3098 women allocated into six treatment groups and one control group.

METHODS

The six intervention groups were offered fish oil capsules in doses of 0.1, 0.3, 0.7, 1.4 and 2.8 g of eicosapentaenoic acid and docosahexaenoic acid per day or 2.2 g of alpha-linolenic acid (ALA) per day from week 17-27 of gestation until delivery.

MAIN OUTCOME MEASURES

Timing of spontaneous delivery.

RESULTS

No differences in timing of spontaneous delivery was detected in the fish oil groups or the flax oil group, compared with the control group. The difference in timing of spontaneous delivery in the group receiving the highest fish oil dose compared with the control group was 0.8 days (95% CI: -2.3 to 1.0). Only a minority of the women in the intervention groups took capsules until delivery.

CONCLUSION

Possible explanations for these findings include no true effect of n-3 fatty acids on spontaneous delivery or a quick-acting effect not detectable in this trial.

Does continuing oral magnesium supplementation until delivery affect labor and puerperium outcome?

OBJECTIVE

To determine the labor and puerperal impact of continuing oral magnesium supplementation until delivery.

STUDY DESIGN

Single-center study with matched controls. In 40 pairs of healthy women with vaginally delivered singleton pregnancies, matched for maternal age, race and parity, maternal and neonatal outcome endpoints were compared in those receiving continuous oral magnesium aspartate supplementation 15-30 mmol/d for at least 4 weeks until delivery (for constipation, calf cramps, preterm contraction without cervical effacement or additional tocolytics) versus non-supplemented controls.

RESULTS

In the magnesium group labor was nonsignificantly longer (stage 1: 326.0+/-187.5 min versus 276.7+/-140.8 min, P = 0.19; stage 2: 52.0+/-44.5 min versus 43.5+/-44.0 min, P = 0.40) and maximum oxytocin dose nonsignificantly higher (14.5+/-9.4 [median 12.0; n=15] versus 10.5+/-6.9 [median 7.5] mU/min, P = 0.28; n = 10). Fewer women had afterpains (12 versus 20, P=0.11), required spasmolysis (3 versus 14, P = 0.005), or could breastfeed their infants exclusively at discharge (24 versus 34, P = 0.04).

CONCLUSION

Continuing oral magnesium supplementation until delivery does not significantly prolong labor or increase the oxytocin requirement, but it significantly impairs breastfeeding competence.