Fetal Doppler hemodynamic changes in spontaneous versus prostaglandin E1-induced active labor.

BACKGROUND: To assess fetal hemodynamic changes before and during active labor, either spontaneous or prostaglandin E1 (PGE1)-induced labor. MATERIALS AND METHODS: This is a prospective longitudinal study and a cohort of 49 healthy women at 37-41+ weeks gestation without signs of fetal distress was investigated until in labor. One group of 23 healthy women had spontaneous active labor, the second group of 26 women was in active labor induced by an intra-cervical administration of PGE1 for elective induction. Blood flow waveform indices (S/D ratio, RI, PI) were assessed by pulsed Doppler ultrasonography from the umbilical artery (UA) and fetal middle cerebral artery (MCA) before and in labor. Both groups were compared for the waveform indices and perinatal outcome including duration of labor, meconium stain, baby sex, birthweight, UA blood gas measurements at delivery, Apgar's scores, prolonged nursery stay (> or =5 days), and NICU admission. RESULTS: Demographic data of the two groups were comparable. During spontaneous active labor, the S/D ratio and RI became significantly decreased in the UA (p<0.05) and the three wave-form indices were decreased more in the MCA (p<0.01, 0.005, 0.05, respectively) compared with those measured before labor. During PGE1-induced active labor, all the waveform indices were not significantly decreased in either the UA or the MCA. The occurrence of abnormal UA blood gas values was significantly more in the PGE1-induced group than in the spontaneous labor group (23.1% v.s. 4.3%; p<0.05). No other adverse perinatal outcomes were observed in either group. CONCLUSIONS: Decreasing impedance in both the UA and MCA during spontaneous labor is a physiological fetal adaptation to labor to prevent fetal cerebral hypoxia by maintaining adequate brain blood flow during normal parturition. This fetal adaptation phenomenon was not observed in the group of PGE1-induced labor with the result of a high incidence of abnormal UA blood gas values.     

Plasma progesterone, serum estriol and plasma HPL determinations during the last trimester to detect changes before spontaneous labor. Comparison of progesterone assay using RIA and CPB

Conflicting results have been published regarding changes in plasma progesterone during the last trimester of pregnancy. Some have demonstrated a fall in plasma progesterone before labor, and this has been taken as a possible explanation of the onset of labor. It has been suggested that the various results could be due to differences in methods for progesterone determination. In this study the progesterone levels were determined by both RIA and CPB. In 11 women the plasma progesterone, human placenta lactogen, and serum estriol were measured weekly during the last trimester of normal pregnancies and immediately after delivery. All samples were analysed radioimmunologically. In order to compare the radioimmunoassay and competitive protein binding techniques (RIA and CPB), the progesterone levels were determined by both methods. This was also done for 80 successive plasma progesterone routine samples drawn from women who were not pregnant or who were in the early stages of pregnancy. Both methods showed a significant rise in the plasma progesterone level during the last 6 weeks before spontaneous labor. However, the values obtained were lower when assayed by CPB than by RIA, presumably because of a higher specificity and a cross reaction in RIA. Serum estriol exhibited increasing values throughout pregnancy, but without a significant rise during the last few weeks. Plasma HPL settled at a constant level during the last few weeks before labor.     

Changes in plasma cyclic AMP and cyclic GMP during spontaneous labor and labor induced by oxytocin, prostaglandin F2 alpha and prostaglandin E2

To investigate the response of cyclic nucleotides to the oxytocic agents administered for induction of labor, plasma concentrations of cyclic AMP (cAMP) and cyclic GMP (cGMP) were determined by radioimmunoassay during spontaneous labor and labor induced by oxytocin (OT), prostaglandin F2 alpha (PGF2 alpha), or PGE2 (PGE2). Subjects were 7 Japanese women in each labor group. Plasma cAMP levels significantly rose at the time of crowning of the fetal head in all 4 groups. They did not increase until that time in the 3 labor groups (spontaneous, OT-induced, and PGF2 alpha-induced labor groups). In the PGE2-induced labor group, plasma cAMP levels were significantly higher at labor onset (mean +/- SEM = 16.5 +/- 1.3 pg/ml) when compared to the pretreatment values (13.7 +/- 1.0 pg/ml), and increased thereafter gradually toward the time of crowning of the head (26.3 +/- 2.0 pg/ml). Plasma cGMP levels in the OT-induced group significantly rose after the onset of labor and remained at a high level until expulsion of the fetus. Plasma cGMP levels in the other groups did not change significantly throughout labor. These results suggest that cAMP may be involved in the labor process induced by PGE2, and that cGMP may be in that induced by OT.     

Plasma progesterone, dehydroepiandrosterone sulfate and estriol levels during labor induction with a sustained-release prostaglandin E2 vaginal insert.

OBJECTIVE: To measure plasma progesterone, dehydroepiandrosterone sulfate (DHEAS) and estriol levels in women induced for labor with a sustained-release vaginal polymer prostaglandin E2 insert, and to analyze the relationships between the changes in hormone levels and Bishop score. METHODS: Twelve primipara and 12 multipara were treated with a sustained-release polymer vaginal prostaglandin E2 insert (0.3 mg/h) for up to 24 h. The Bishop score was assessed at the start and end of therapy, and serum samples were collected at 4-h intervals. Plasma levels of progesterone, DHEAS and estriol were measured by specific radioimmunoassays. RESULTS: Exposure averaged 13.5 +/- 7.2 h. Progesterone levels decreased in the majority of patients (79.2%) after the start of therapy. Higher baseline DHEAS and estriol levels were observed among women who achieved an improvement in Bishop score of at least 4 during prostaglandin E2 treatment. CONCLUSIONS: Higher DHEAS and estriol levels prior to labor induction with prostaglandin E2 may be indicators of a favorable labor outcome. Additional studies are needed to substantiate the decrease in progesterone levels observed in this study and the importance of this phenomenon for the mechanism of labor induction with prostaglandin E2.     

Urinary nitric oxide metabolite changes in spontaneous and induced onset active labor

BACKGROUND: The aim of this prospective, randomized study was to investigate the changes in urinary nitric oxide (NO) metabolite between the latent and the active phases of spontaneous and either prostaglandin E(1) (PGE(1)) or prostaglandin E(2) (PGE(2))-induced labors. METHODS: Eighty-eight singleton pregnant women at 36-41(+) weeks' gestation without signs of fetal distress were enrolled. The first group consisted of 29 pregnant women in whom labor was induced by PGE(1) applied intravaginally. The second group consisted of 29 pregnant women with labor induced by PGE(2) applied intracervically. The third group consisted of 30 women, who had spontaneous active labor. Clinical data of the three groups were assessed as labor progressed. RESULTS: Urinary nitric oxide/creatinine (U NO/Cr) decreased significantly after the onset of active labor in all three groups (p < 0.005), with the percentage decline of 42.2%, 28.6% and 10.1%, respectively. The magnitude of the difference in decline in U NO/Cr after active labor between the PGE(1)-induced and the spontaneous labor group was significantly reduced (p = 0.0047) after adjustment for potential confounders using the generalized estimating equations test (GEE). The duration of the latent phase was significantly shortened in the PGE(1)-induced group as compared with the spontaneous labor group (p < 0.01). CONCLUSIONS: Decreased U NO/Cr may facilitate transition from the latent to the active phase either in spontaneous or induced labors. Our results indicate that U NO/Cr can serve as an easily obtained marker for use in controlling myometrial contractility and cervical ripening at the onset of active labor. The nitric oxide system is present in the human uterus and may contribute to uterine quiescence during pregnancy and show down-regulation in U NO/Cr at the initiation of active labor.     

Induction of labor with oral prostaglandin E2.

Prostaglandin E (PGE2) was administered orally for induction of labor to 100 patients. Active labor and progression occurred in 92 per cent of these cases. The dosage regimen used was 0.5 to 1.5 mg. hourly. Amniotomy was performed in most cases once active labor and progression were noted. There were 83 vaginal deliveries and 12 cesarean sections. There were eight failure of induction, one patient left the study, and one was not delivered at that admission. Fetal distress occurred in 10 patients but this was related to cord and placental problems and not to PGE2 per se. Side effects were minimal, the most prominent being nausea and vomiting. Total labor in hours compares to normal labor. Over-all, labor in primigravidas averaged 10.15 hours and 6.5 hours in multiparas. There was a direct relationship of the Bishop score to the start of active labor and progression. PGE2 appears safe and efficacious for inductions of labor at terms.     

Intracervical misoprostol and prostaglandin E2 for labor induction.

OBJECTIVES: To compare the safety and efficacy of misoprostol with PGE(2) for induction of labor by intracervical administration. METHODS: Eighty-six women with indications for labor induction at term were randomly assigned to two groups. Each woman received either 50 microg of misoprostol or 0.5 mg of prostaglandin E(2) intracervically. If labor was not initiated after 4 h, the same dose was repeated every 4 h to a maximum of 200 microg of misoprostol or 1.5 mg of PGE(2) until adequate labor was achieved. RESULTS: Forty-three women were allocated to the misoprostol group and 43 to the prostaglandin E(2) group. Misoprostol was more effective than PGE(2) in producing cervical changes (P<0.025). Delivery within 12 h after the first administration occurred more often in the misoprostol group than in the PGE(2) one (85% vs. 56%, P<0.05). Less patients in the misoprostol group required oxytocin augmentation than in the PGE(2) one (16.3% vs. 39.5%, P<0.05). Uterine tachysystole and hyperstimulation occurred more frequently in the misoprostol group (44.1%) than in the PGE(2) group (18.7%) (P<0.05). Nevertheless, no statistically significant differences were noted between the two groups including mode of delivery and neonatal or maternal adverse outcome. The interval from induction to vaginal delivery was significantly shorter in the misoprostol group (480+/-172 min vs. 657+/-436 min, P<0.01). CONCLUSIONS: Compared with prostaglandin E(2), intracervical misoprostol is more effective in cervical ripening and labor induction at term. The higher frequency of uterine hypercontractility associated with the use of misoprostol did not increase the risk of adverse intrapartum and neonatal outcomes.     

Inducing labor with oral prostaglandin E2 tablets.

Labor was successfully induced by forewater amniotomy and oral administration of prostaglandin E2 tablets in 91.3% of 153 women with singleton pregnancies. Deliveries occurred within 12 hours for more than 90% of the successfully induced patients. Although not statistically significant, a higher pelvic score appeared to be associated with shorter induction-to-delivery intervals. There were no harmful side effects for either mother or baby; only 14.5% experienced minor side effects, primarily gastrointestinal upsets.     

Inducing labor with oral prostaglandin E2 in Khartoum hospital.

Prostagland-n E2 (PGE2) was administered orally to 109 patients to induce labor. Sixty-five of these patients had an amniotomy prior to PGE2 administration. PGE2 was administered to the remaining. 44, who subsequently underwent amniotomy only after their cervices had reached approximately 6 cm dilation. Labor was successfully induced in 95 patients, but its duration was shorter when amniotomy was immediatedly followed by PGE2 administration. Failed cases were successfully managed with amniotomy and oxytocin infusion. Maternal side effects were minimal. No fetal complications occurred.     

Elective induction vs. spontaneous labor associations and outcomes

OBJECTIVE: To determine factors and outcomes associated with elective medical induction of labor as compared with spontaneous labor in low-risk women. STUDY DESIGN: Using a birth certificate database including 11,849 low-risk, laboring women, univariate and multiple logistic regression was used to evaluate demographic and obstetric factors associated with elective labor induction. Low risk was defined as singleton, vertex, 37-41 weeks' gestation, no prior cesarean section, and no presenting medical/obstetric diagnoses considered indications for cesarean or induction. Adverse neonatal outcome was defined as 1- or 5-minute Apgar score < 7, neonatal intensive care unit admission or respiratory distress. Spontaneously laboring women (n = 10,608) were compared with women who underwent induced labor for no apparent medical/obstetric reason (n = 1,241). Interventions and outcomes during and after labor induction were adjusted for relevant associated variables. RESULTS: Odds ratios for epidural anesthesia, cesarean delivery and diagnoses of nonreassuring fetal heart rate patterns were independently increased following elective induction; odds ratios for cephalopelvic disproportion, instrumental delivery and adverse neonatal outcome were not. Maternal length of stay was 0.34 days longer with induction than with spontaneous labor (p < 0.0001). Slightly more induced labors ended before midnight. CONCLUSION: As compared with spontaneous labor, elective labor induction is independently associated with more intrapartum interventions, more cesarean deliveries and longer maternal length of stay. Neonatal outcome is unaffected.     

Prostaglandin E2 cervical ripening without subsequent induction of labor.

OBJECTIVE: To determine whether outpatient administration of intracervical prostaglandin (PG) E2 gel decreases the interval to delivery and duration of labor. METHODS: A randomized, double-blind, placebo-controlled trial compared the intracervical placement of 0.5 mg PGE2 gel with placebo in 61 pregnant women at 38 weeks' or greater gestation with Bishop scores less than 9. Transvaginal cervical length, fetal fibronectin, and Bishop score were assessed before gel placement. Subjects were then allowed to go into spontaneous labor unless an indication for induction developed. RESULTS: Thirty women were assigned to PGE2 and 31 to placebo. There were no significant demographic differences between the groups and there were no differences in cervical length, fetal fibronectin status, or Bishop scores. Fifteen women in the PGE2 group and five in the placebo group went into labor and delivered within the first 2 days after gel placement (P = .007). The median interval to delivery was significantly shorter in the PGE2 group, at 2.5 days, compared with placebo, at 7 days (P = .02). Nulliparas in the PGE2 group had a median interval to delivery of 2 days, compared with 7 days for nulliparas receiving placebo (P = .03). Active phases of labor were significantly shorter in the PGE2 group and for women with a negative fetal fibronectin test who received PGE2. CONCLUSION: Outpatient administration of intracervical PGE2 gel shortened intervals to delivery and shortened labor.     

Suppression of IL-2 and IFN-gamma production in women with spontaneous preterm labor

AIMS: To determine the TH-1/TH-2 cytokine pattern in peripheral blood leukocytes (PBL) in late second- and third trimester in normal pregnancies, in comparison to patients with spontaneous preterm delivery (PTD; < 37 completed weeks' gestation). METHODS: A cross-sectional retrospective study was performed in a tertiary care obstetric unit with healthy non-pregnant women (n=7); healthy pregnant women (n=25); patients (n=25) with preterm labor (defined as uterine contractions or changes in cervical length). The phenotypic analysis of TH-1/TH-2 immune deviation was examined in PBL. RESULTS: 26% PTD (n=13) were recorded. Patients delivering at term (n=37, 74%) were characterized by an upregulation of IL-2, IFN-gamma and IL-4 production during weeks 20-25, followed by a strong suppression in cytokine production, except for TGF-beta. Towards the end of pregnancy cytokine levels returned to normal as observed in non-pregnant women. In contrast, PTD showed an inverse pattern for IL-2 and IFN-gamma with marked suppression in IL-2 and IFN-gamma production between weeks 20-25, followed by a strong stimulation of these cytokines. No differences were observed in IL-4 and TGF-beta production. CONCLUSION: An inverse pattern in IL-2 and IFN-gamma production in PBLs between weeks 20-30 is seen in PTD as compared to patients delivering at term.     

Oral prostaglandin E2 for induction of labor

PGE2 (prostaglandin E2) had been successfully used in initiating labor in term pregnancies (Karim and Sharma, 1971). This study evaluates the safety and efficacy of prostaglandin for induction of labor in 23 patients (gestational length, 38-41 weeks; mean age, 27; age range, 17 to 40; parity 0 to 6). 20 received an oral PGE2 0.5 mg tablet hourly while 3 received an initial dose of 0.5 mg with 0.5 mg incremental increase hourly. 20 patients delivered vaginally liveborn infants without neonatal depression according to Apgar score and subsequent behavior in the nursery. 2 patients delivered by C-section and 1 was excluded from the study because of inadequate duration of treatment. Mean time to delivery was 5 hours, 47 minutes; mean drug dose, 2.53 mg. Mild transient emesis and diarrhea occurred in 2 patients, and emesis only in 1. Bishop induction score did not correlate with total dose of PGE2 used. Parity correlated negatively with dose necessary to achieve delivery (p0.05). The findings confirm the efficacy and safety of oral PGE, which provides an alternate drug and route for induction of labor. Oxytocin induction is briefly compared with prostaglandin induction.