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PubMed1984

Increased immunoreactive erythropoietin in cord serum after labor.

Since several hours of hypoxemia in fetal animals is sufficient to cause an increase in the plasma erythropoietin level and since labor may be associated with fetal hypoxemia, this study was undertaken to determine if erythropoietin levels in cord blood were higher in fetuses subjected to labor. Two groups of term (37 to 41 weeks) singleton pregnancies were compared: (1) those delivered by elective repeat cesarean section without prior labor (n = 18) and (2) those delivered vaginally (n = 23). Erythropoietin was measured by a radioimmunoassay in which a highly purified human erythropoietin (70,000 U/mg of protein) was used and which has a sensitivity limit of 4 to 5 mU/ml. The mean cord serum erythropoietin level was higher in pregnancies with labor (46 +/- 34 mU/ml, mean +/- SD) compared to those without (26 +/- 10, p less than 0.02). There were no differences between the two groups for maternal age, gestational age, birth weight, infant sex, or Apgar scores. No association of erythropoietin with either gestational age or sex was found. In 11 pregnancies without labor, comparisons were made among simultaneously obtained samples of umbilical arterial plasma, umbilical venous plasma, and mixed cord serum. Although there were no differences between umbilical arterial and umbilical venous plasma erythropoietin levels (21.3 +/- 9.3 versus 19.0 +/- 7.8 mU/ml), mixed cord serum was inexplicably higher (24.4 +/- 9.5 mU/ml, p less than 0.01). We concluded that in uncomplicated pregnancies the duration and intensity of labor are sufficient to cause an increase in the fetal erythropoietin level at delivery.

Adolescent↗
PubMed1989

Effects of physical activity on maternal plasma beta-endorphin levels and perception of labor pain.

Thirty-six women in their second or third pregnancies were studied in two groups (control and exercise) to determine whether plasma alpha-endorphin levels could be elevated by exercise conditioning during pregnancy. Aerobic training was performed on a bicycle ergometer. Both groups were monitored throughout pregnancy by frequent gynecologic examinations. During labor, both groups of women had pain perception assessment. Blood was sampled for levels of beta-endorphin, cortisol, human growth hormone, and prolactin. Plasma beta-endorphin was found elevated compared to controls in patients who exercised throughout pregnancy. This difference was maintained throughout labor and pain perception during labor was reduced in the patients who exercised. Cortisol, human growth hormone, and prolactin levels were lowered during labor for the exercise-conditioned patients. Exercise conditioning during pregnancy seems to be beneficial in reducing pain perception during labor (as determined by measurement of visual analog pain scales) and in reducing stress levels during labor.

Arm↗
PubMed1996

Trial of labor in patients with a previous lower uterine vertical cesarean section.

OBJECTIVE: Our purpose was to determine the efficacy and safety of a trial of labor in patients previously delivered at least once by a lower uterine vertical cesarean section. STUDY DESIGN: A retrospective review was performed at a single tertiary perinatal center, The University of Florida Health Science Center, Jacksonville. The medical records of all patients with a previous low vertical cesarean section who underwent a trial of labor during a 72-month period from January 1988 until December 1993 were reviewed. The medical records of the next two patients who did not have a prior uterine incision admitted to labor and delivery after the index case served as the controls. The duration and outcome of labor, including mode of delivery, maternal and perinatal morbidity, and birth trauma were evaluated. RESULTS: Of 77 patients with a previous low vertical cesarean incision, 11 (14.3%) had a repeat operation compared with 14 of 154 patients (9.0%) in the no previous cesarean section group (not significant). No differences were noted in the incidences of operative vaginal deliveries or prolonged duration of the first or second stages of labor, or in the rate or maximum dose of oxytocin infusion between the two groups. One patient in the previous cesarean section group had uterine rupture. The incidence of umbilical artery pH < or = 7.20 was similar. No difference in the number of infants with 1- or 5-minute Apgar scores < or = 7 was noted. CONCLUSION: A trial of labor in women with previous low vertical cesarean sections results in an acceptable rate of vaginal delivery and appears safe for both mother and fetus.

Adult↗
PubMed1997

Nulliparous active labor, epidural analgesia, and cesarean delivery for dystocia.

OBJECTIVE: Our purpose was to examine the effect of epidural analgesia on dystocia-related cesarean delivery in actively laboring nulliparous women. STUDY DESIGN: Active labor was confirmed in nulliparous women by uterine contractions, cervical dilatation of 4 cm, effacement of 80%, and fetopelvic engagement. Patients were randomized to one of two groups: epidural analgesia or narcotics. A strict protocol for labor management was in place. Patients recorded the level of pain at randomization and at hourly intervals on a visual analog scale. Elective outlet operative vaginal delivery was permitted. RESULTS: One hundred women were randomized. No difference in the rate of cesarean delivery for dystocia was noted between the groups (epidural 8%, narcotic 6%; p = 0.71). No significant differences were noted in the lengths of the first (p = 0.54) or second (p = 0.55) stages of labor or in any other time variable. Women with epidural analgesia underwent operative vaginal delivery more frequently (p = 0.004). Pain scores were equivalent at randomization, but large differences existed at each hour thereafter. The number of patients randomized did not achieve prestudy estimates. A planned interim analysis of the results demonstrated that we were unlikely to find a statistically significant difference in cesarean delivery rates in a trial of reasonable duration. CONCLUSIONS: With strict criteria for the diagnosis of labor and with use of a rigid protocol for labor management, there was no increase in dystocia-related cesarean delivery with epidural analgesia.

Adult↗
PubMed1997

A comparison of intermittent vaginal administration of misoprostol with continuous dinoprostone for cervical ripening and labor induction.

OBJECTIVE: Our purpose was to compare the effect of vaginal administration of misoprostol (Cytotec) with that of dinoprostone (Cervidil) on cervical ripening and labor induction. STUDY DESIGN: Two hundred patients with indications for induction of labor and unfavorable cervical examinations were randomly assigned to receive vaginally administered misoprostol (prostaglandin E1) or the dinoprostone (prostaglandin E2) vaginal insert. Twenty-five microgram tablets of misoprostol were placed in the posterior vaginal fornix every 4 hours for a maximum of six doses. Additional misoprostol was not given after either spontaneous rupture of membranes, adequate cervical ripening (Bishop score of > or = 8 or cervical dilatation of > or = 3 cm), or beginning of active labor. The vaginal insert, Cervidil, containing 10 mg of dinoprostone in a timed-release preparation was placed in the posterior vaginal formix for a maximum period of 24 hours. The vaginal insert was removed for spontaneous rupture of membranes, entry into active labor, adequate cervical ripening, or abnormality of uterine contractile pattern or fetal cardiac activity. RESULTS: Of the 200 patients enrolled, 99 were randomized to misoprostol and 101 to dinoprostone. The average interval from start of induction to vaginal delivery was 1 hour shorter in the misoprostol group (1296.7 +/- 722.1 minutes) than in the dinoprostone group (1360.0 +/- 792.0 minutes), but this difference was not statistically significant (p = 0.97). Oxytocin augmentation of labor was used in 50 (50.5%) misoprostol-treated patients and 43 (43.5%) dinoprostone-treated patients (relative risk 1.14, 95% confidence interval 0.86 to 1.51, p = 0.35). There were no significant differences between routes of delivery with misoprostol or dinoprostone. Overall, 38 patients (19.3%) had cesarean deliveries. There was a significantly lower prevalence of tachysystole (six or more uterine contractions in a 10-minute window for two consecutive 10-minute periods) in the misoprostol group (7.1%) than in the dinoprostone group (18.4%) (relative risk 0.52, 95% confidence interval 0.31 to 0.89, p = 0.02). There were no significant differences in frequency of uterine hyperstimulation or hypertonus. Abnormal fetal heart rate tracings were found in 23 (23.2%) of misoprostol-treated patients and 35 (35.7%) of dinoprostone-treated patients (relative risk 0.73, 95% confidence interval 0.52 to 1.01, p = 0.0546). No significant differences were found in meconium passage, 1- or 5-minute Apgar scores < 7, neonatal resuscitations, or admissions to the neonatal intensive care unit between the two groups. CONCLUSIONS: Vaginally administered misoprostol is as effective as dinoprostone for cervical ripening and the induction of labor. Mean time intervals to delivery, need for oxytocin augmentation, and routes of delivery were similar between the two groups. Incidence of uterine tachysystole with misoprostol every 4 hours was significantly less than with dinoprostone.

Cervix Uteri↗
PubMed1997

The effect of magnesium sulfate therapy on the duration of labor in women with mild preeclampsia at term: a randomized, double-blind, placebo-controlled trial.

OBJECTIVE: The primary outcome was to determine whether magnesium sulfate therapy prolongs the duration of labor in women with mild preeclampsia. Secondary outcomes were to assess the side effects associated with magnesium sulfate therapy: hours and maximum dose of oxytocin, incidence of progression to severe preeclampsia, incidence of cesarean delivery, change in maternal hematocrit, incidence of postpartum hemorrhage, incidence of maternal infection, and Apgar scores. STUDY DESIGN: Women with a diagnosis of mild preeclampsia at term were randomized to receive standard therapy during labor and for 12 hours post partum with either magnesium sulfate (n = 67) or a matching placebo solution (n = 68). RESULTS: There was no difference between magnesium sulfate and placebo with respect to the primary outcome variables: total length of labor (median 17.8 hours vs 16.5 hours, p = 0.7) and length of the active phase of labor (median 5.4 hours vs 6.0 hours, p = 0.5). In addition, no difference was observed in the secondary outcome variables: hours of oxytocin use, change in hematocrit, frequency of maternal infection, progression to severe preeclampsia, incidence of cesarean delivery, and Apgar scores. Although not statistically significant, the incidence of postpartum hemorrhage was approximately fourfold greater in the magnesium sulfate group (relative risk 4.1, 95% confidence interval 0.5 to 35.4). There was a significant difference in the maximum dose of oxytocin used (13.9 +/- 8.6 mU/min with magnesium sulfate vs 11.0 +/- 7.6 mU/min with placebo, p = 0.036). CONCLUSION: The use of magnesium sulfate during labor in women with mild preeclampsia at term does not affect any component of labor but did necessitate a higher dose of oxytocin.

Adult↗
PubMed1998

Trial of labor after cesarean delivery: the effect of previous vaginal delivery.

OBJECTIVE: This study examined the effects of order of previous modes of delivery on the rate of cesarean delivery and duration of a trial of labor among women with a history of 1 previous cesarean delivery and 1 previous vaginal delivery. STUDY DESIGN: The medical records of 4393 women at our institution who were seen June 1984-July 1996 for a trial of labor after a previous cesarean delivery were abstracted. The 800 women with a history of 1 previous cesarean and 1 previous vaginal delivery were included in this analysis. They were split into 2 groups by obstetric history: (1) 1 cesarean delivery followed by 1 vaginal delivery (vaginal last) and (2) 1 vaginal delivery followed by 1 cesarean delivery (cesarean last). Patient characteristics, durations of labor, and rates of cesarean delivery were compared with chi2 analysis, the Student t test, and the Wilcoxon rank sum test. Possible confounding variables were controlled for with multivariate logistic regression. RESULTS: The rates of cesarean delivery for the vaginal last and cesarean last groups were 7.2% and 14.7%, respectively (P = .002). The median durations of labor for the vaginal last and cesarean last groups were 5.6 and 7.0 hours, respectively (P = .01). The differences in cesarean rates and durations of labor were seen regardless of the indication for the previous cesarean delivery. CONCLUSIONS: Among women with 1 previous cesarean and 1 previous vaginal delivery, those whose most recent delivery was vaginal had a lower rate of cesarean delivery and shorter duration of labor than did those whose most recent delivery was cesarean.

Adult↗
PubMed1998

Uterine relaxation responses to calcitonin gene-related peptide and calcitonin gene-related peptide receptors decreased during labor in rats.

OBJECTIVES: Our purpose was to investigate (1) whether uterine relaxation responses to calcitonin gene-related peptide are differentially regulated during pregnancy and labor, (2) the involvement of nitric oxide in smooth muscle relaxant action of calcitonin gene-related peptide in the rat uterus, (3) whether receptors for calcitonin gene-related peptide are expressed in rat uterus, and if so (4) whether the concentrations of these receptors are differently regulated during pregnancy and labor. STUDY DESIGN: Rats were killed on day 18 of gestation, at the time of spontaneous labor, or postpartum day 2. The uteri were removed for in vitro contractility measurements, nitric oxide production, and calcitonin gene-related peptide receptor binding assay. RESULTS: (1) Calcitonin gene-related peptide induced a dose-dependent relaxation in spontaneously contracting uterine strips from pregnant rats on day 18 of gestation; (2) the relaxation effects of calcitonin gene-related peptide on the uterus were decreased during spontaneous delivery at term and post partum compared with that during pregnancy; (3) calcitonin gene-related peptide-induced relaxation was inhibited by pretreatment of the uterine tissue with a calcitonin gene-related peptide receptor antagonist, calcitonin gene-related peptide(8-37); (4) nitric oxide synthesis inhibitor (N(G)-nitro-L-arginine methyl ester) and soluble guanylate cyclase inhibitor (LY83583) significantly decreased calcitonin gene-related peptide-induced relaxation of the rat uterus during pregnancy; (5) calcitonin gene-related peptide increased the uterine nitric oxide production in pregnant rats, and this increase was obliterated in the presence of calcitonin gene-related peptide(8-37); and (6) calcitonin gene-related peptide receptors are present in rat uterus, and the concentration of these receptors dramatically increases during pregnancy and decreases during labor at term. CONCLUSIONS: Calcitonin gene-related peptide inhibits uterine spontaneous contractions in rats during pregnancy but not during labor and post partum. The inhibitory effects of calcitonin gene-related peptide on uterine contractility appear to be modulated, at least in part, by the activation of nitric oxide generation in the rat uterus. Changes in calcitonin gene-related peptide receptors could contribute to the changes in calcitonin gene-related peptide-mediated uterine relaxation during pregnancy and labor.

Aminoquinolines↗
PubMed1998

Does magnesium sulfate given for prevention of eclampsia affect the outcome of labor?

OBJECTIVE: The purpose of this study was to determine whether magnesium sulfate given for prevention of eclampsia affected labor outcomes compared with phenytoin, which is not known to impede uterine activity when given in anticonvulsant doses. STUDY DESIGN: Secondary analysis was performed of a study of women with pregnancy-induced hypertension who were admitted for delivery and randomly assigned to receive either magnesium sulfate or phenytoin for eclampsia prophylaxis. Nulliparous women with a singleton pregnancy in cephalic presentation at term were selected for analysis in an effort to limit the influence of confounding variables such as preterm birth and malpresentations on labor management and outcomes. Similarly, women who had severe preeclampsia and who received labor epidural analgesia were excluded. RESULTS: A total of 2138 women were randomized to receive magnesium sulfate or phenytoin in the primary study. A total of 905 nulliparous women met the inclusion criteria for this secondary analysis; 480 had been randomized to phenytoin and 425 were given magnesium sulfate. The two groups were similar demographically. Labor outcomes such as (1) oxytocin stimulation, (2) admission-to-delivery intervals, (3) prolonged second-stage labor, (4) forceps delivery, and (5) cesarean delivery were not affected by maternal treatment with magnesium sulfate. CONCLUSION: Compared with phenytoin, magnesium sulfate given for intrapartum treatment of pregnancy-induced hypertension does not significantly affect labor outcomes.

Adult↗
PubMed1998

Diurnal rhythms of labor and delivery in women: modulation by parity and seasons.

OBJECTIVES: Our purpose was to evaluate in women the diurnal (24 hour) rhythms of the onset of labor and time of delivery and their modulation by parity and seasons. STUDY DESIGN: A retrospective analysis was performed on 15,910 at term deliveries of single fetuses with noninduced labor. RESULTS: A diurnal rhythm of labor onset, with peak frequency at 8 PM and 9 AM was observed in nulliparous women but not in multiparous women. No diurnal rhythm of labor length was detectable. A diurnal rhythm of delivery, with peak values at 2 PM was evident in nulliparous but not in multiparous women. In nulliparous women the two acrophases of the diurnal rhythm of labor onset were closer in summer (10 hours) than in winter (13 hours). The acrophase of the diurnal rhythm of delivery progressively shifted to earlier hours from winter (5 PM) to summer (1 PM). CONCLUSIONS: These data show the attenuation of the diurnal rhythms of labor and delivery in multiparous women and their modulation by seasons.

Circadian Rhythm↗
PubMed1999

Induction of labor and the relationship to cesarean delivery: A review of 7001 consecutive inductions.

OBJECTIVE: The goal of this project was to study the increasing risk of induction of labor in a community hospital and to determine whether it had an adverse effect on the rate of cesarean delivery. STUDY DESIGN: From January 1, 1990, through July 31, 1997, 18,055 consecutive singleton pregnancies in women who were candidates for labor were reviewed via a comprehensive perinatal database. The risk of and indication for induction were reviewed. Cesarean delivery rates were calculated for nulliparous and multiparous patients by indication for induction and were compared with rates for patients who had spontaneous labor. Overall trends in cesarean delivery were reviewed for the duration of the study period. RESULTS: The annual induction rate significantly rose from 32% to 43% at the conclusion of the study period. Labor was induced in nearly 40% of nulliparous patients. Postdate pregnancy was the most common indication for induction, although few patients were at or beyond 42 weeks' gestation. The cesarean delivery rate remained at or below 20% for the years of the study. No increase was noted in spite of the increasing risk of induction. However, for nulliparous patients who had elective induction of labor, the risk of cesarean delivery was twice that of nulliparous patients who had spontaneous labor. CONCLUSION: The use of induction methods has significantly increased in this community hospital. More than 40% of patients are now candidates for induction. The cesarean delivery rate remains low in this facility in spite of a marked increase in risk of operative delivery for nulliparous patients who undergo induction.

Causality↗
PubMed1999

Oral nicardipine versus intravenous magnesium sulfate for the treatment of preterm labor.

OBJECTIVE: The aim of this study was to compare the efficacy and safety of oral nicardipine in acute therapy for preterm labor with those of parenteral magnesium sulfate. STUDY DESIGN: Patients between 24 and 34 weeks' gestation with documented preterm labor were randomly assigned to receive oral nicardipine (n = 57) or intravenous magnesium sulfate (n = 65) as initial tocolytic therapy. Patients in the nicardipine group received a 40-mg loading dose and then 20 mg every 2 hours as needed to stop contractions (total 80 mg). Patients in the magnesium sulfate group received a 6-g bolus followed by 2 to 4 g/h to provide uterine quiescence. Patients could be switched to another tocolytic regimen if they continued to have contractions after 6 hours of therapy. The main outcome variables examined were time to uterine quiescence, time gained in utero, recurrence of preterm labor, failure of tocolysis, and pertinent maternal and neonatal outcomes. RESULTS: There were no significant differences in maternal demographic characteristics between the groups. Among patients who responded with uterine quiescence within 6 hours, there was a significant decrease in the time to uterine quiescence in the nicardipine group (P <.01). Patients in the magnesium sulfate group were more likely to have recurrence of preterm labor necessitating further tocolytic attempts (P =.048). The patients in the magnesium sulfate group had more adverse side effects, mainly nausea and vomiting (P =.004). There were no differences in birth weight, estimated gestational age at delivery, or neonatal complications between the 2 groups. CONCLUSIONS: Oral nicardipine is an effective, safe, and well-tolerated tocolytic agent. In this prospective clinical trial patients randomly assigned to receive oral nicardipine had arrest of preterm labor more rapidly than did those randomly assigned to receive parenteral magnesium sulfate. Patients who received magnesium sulfate were more likely to have adverse medication effects and recurrent preterm labor.

Administration, Oral↗
PubMed2002

Association of the Gln27Glu polymorphism of the beta-2-adrenergic receptor with preterm labor.

OBJECTIVES: To investigate a potential association between the beta-2-adrenergic receptor (B2AR) polymorphisms occurring at amino acid positions 16 (Arg16Gly) and 27 (Gln27Glu) and preterm labor. METHODS: Eighty patients with preterm labor and 76 control subjects were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). RESULTS: A significant association was found between Gln27Glu substitution and preterm labor (P=0.001). The frequency of Gly16 and Glu27 alleles were found to be higher in patients than in control women (0.54 vs. 0.48 and 0.42 vs. 0.26, respectively), and the odds ratio for the occurrence of preterm labor was 2.14 (95% CI, 1.32-3.46; P=0.002) for the Glu 27 allele. An early delivery was noted in 52.5% of patients. CONCLUSION: The Gln27Glu polymorphism of the B2AR gene may have a role in molecular pathogenesis of preterm labor. Glu27 allele in patients with preterm labor might be a risk factor for deliveries before 37 weeks of gestation.

Adult↗
PubMed2003

Duration of ruptured membranes and extended labor are risk factors for HIV transmission.

OBJECTIVES: To determine the effects of duration of ruptured membranes (DRM) and duration of labor in HIV transmission. METHODS: A retrospective cohort study of 366 HIV-infected pregnant women and their infants analyzed the effects of these two variables; the cut-off point for transmission increase was estimated using a ROC curve. A multivariate analysis was performed with the most important risk factors according to the literature: maternal age, lymphocyte count, use of invasive procedures during gestation, antiretroviral treatment during pregnancy and labor, mode of delivery, newborn weight, DRM, labor duration, and the interaction of these last two factors. RESULTS: The cut-off points were estimated at 6 h for DRM and at 5 h for labor duration. A lymphocyte count below 500 cells/ml, use of invasive procedures, use of antiretroviral treatment during pregnancy and interaction between DRM, and labor duration remained significant in perinatal HIV transmission (P<0.05). CONCLUSIONS: An increased DRM increased perinatal HIV transmission when it was associated with prolonged labor.

Cohort Studies↗
PubMed2004

Labor augmentation in an Egyptian teaching hospital.

OBJECTIVES: The study documented facility-based obstetric practices for normal labor in Egypt for the first time, to determine their relationship to evidence-based medicine. This paper describes the labor augmentation pattern observed. METHODS: 176 cases of normal labor were observed by medically-trained observers using a checklist. Ward activities were also documented. Observed women were interviewed postpartum and all findings were shared with the providers for their feedback. RESULTS: Labor was augmented in 91% (165) of the labors observed; this was inappropriate for 93% or 154 women. Reasons for inappropriateness were: oxytocin ordered at the first vaginal exam (41%); in spite of intact membranes (36%), at the time of membrane rupture (42%), in spite of good progress (24%), or a combination of these. The monitoring of oxytocin-receiving women and their babies was inadequate. CONCLUSIONS: Labor augmentation and monitoring deviated from evidence-based guidelines. Obstacles to implementing protocols need to be explored.

Egypt↗
PubMed2000

Labor after previous cesarean: influence of prior indication and parity.

OBJECTIVE: To determine whether the risk of cesarean for women who had trials of labor after one prior cesarean differs from that of nulliparas overall and by indications for those cesareans. METHODS: We reviewed medical records of women who had trials of labor after cesareans between July 1984 and June 1996, and of nulliparas who delivered between December 1994 and August 1995. Cesarean rates for women with prior cesareans were compared with the rates for nulliparas overall and by prior cesarean indication (breech, failure to progress, nonreassuring fetal testing, or other). Lengths of labor for women who had repeat cesareans for failure to progress in index pregnancies were compared by prior cesarean indication. RESULTS: The cesarean rate was 28.7% (634 of 2207) for the prior cesarean group and 13.5% (219 of 1617) for nulliparas (P =.001), and varied according to the prior cesarean indication (13.9%, 37.3%, 25. 4%, and 24.8% for breech, failure to progress, nonreassuring fetal testing, and other, respectively). Mean durations of labor in the index pregnancies for women who had cesareans for failure to progress were 13.9, 11.5, 13.4, and 15.1 hours for breech, failure to progress, nonreassuring fetal testing, and other, respectively. CONCLUSION: Overall rates of cesareans were higher for women with one prior cesarean than for nulliparas. Rates of cesareans after trials of labor were related to the prior cesarean indications. Rates were highest for women whose prior cesareans were for failure to progress and lowest for women whose prior cesareans were for breech. The latter group had a rate that was essentially identical to that of nulliparas. Among women with cesareans for failure to progress in index pregnancies, lengths of labor were shorter for those whose prior cesareans were for failure to progress than for those whose prior cesareans were for other indications, suggesting that physicians may intervene earlier in these cases.

Female↗
PubMed2001

Effect of labor on infant morbidity and mortality with preterm premature rupture of membranes: United States population-based study.

OBJECTIVE: To evaluate whether labor, in the setting of premature rupture of membranes (PROM), affects infant morbidity and mortality rates. METHODS: We derived data for this population-based cohort study from the United States national linked birth infant death data sets, comprised of singleton live births delivered between 1995 and 1997. We included women (n = 34,594) who had preterm PROM more than 12 hours and delivered between 23 and 32 weeks' gestation. Birth records were used to determine whether delivery occurred with or without labor. Infants with birth weights below the tenth percentile for gestational age were classified as small for gestational age (SGA) on the basis of a nomogram of all singleton births in the United States between 1995 and 1997. Primary outcomes were early neonatal (0-6 days), late neonatal (7-27 days), postneonatal (28-365 days), and infant death (0-365 days). Secondary outcomes included respiratory distress syndrome (RDS), assisted ventilation, and neonatal seizures. Risks of infant mortality and morbidity from labor were examined separately for SGA and non-SGA infants. RESULTS: Overall rates were infant death 11.6%, RDS 15.1%, assisted ventilation 25.9%, and neonatal seizure 0.2%. Labor was associated with higher incidence of early neonatal death in SGA infants (adjusted relative risk [RR] 1.24, 95% confidence interval [CI] 1.11, 1.38) but had no effect on other outcomes. Among non-SGA infants, labor had no effect on infant death but was associated with higher rates of RDS (RR 1.15, 95% CI 1.08, 1.22) and assisted ventilation (RR 1.16, 95% CI 1.08, 1.24). CONCLUSION: Although labor was associated with a slightly higher mortality rate in SGA infants and slightly more respiratory morbidity in non-SGA infants, recommendations regarding clinical treatment should await future clinical trials.

Adult↗
PubMed2001

Excessive uterine activity accompanying induced labor.

OBJECTIVE: To estimate the incidence and timing of excessive uterine activity accompanying induction of labor with misoprostol using different routes (oral or vaginal) and forms (intact tablet or crushed) and to compare these with dinoprostone gel, oxytocin, and spontaneous labor. METHODS: This retrospective cohort study included 519 women at term who had labor induced and 86 women at term in spontaneous labor. Induction agents included misoprostol, dinoprostone, or oxytocin. Fetal heart rate and uterine activity tracings were analyzed independently by three maternal-fetal medicine physicians. The diagnosis of tachysystole or hyperstimulation required the agreement of two or more reviewers. RESULTS: The incidence of tachysystole was highest with misoprostol administered by vaginal tablet (misoprostol vaginal tablet 50 microg every 4 hours, 48.6%; vaginal tablet crushed 50 microg and suspended in hydroxyethyl gel every 4 hours, 30.7%, P =.009; oral tablet 50 microg every 4 hours, 22.2%, P =.001; oral tablet crushed 50 microg every 4 hours, 15.5%, P <.001; dinoprostone gel, 33.0%, P =.022; intravenous oxytocin, 30.2%, P =.027; and spontaneous onset of labor, 23.3%, P <.001). Hyperstimulation occurred more often with dinoprostone gel (16.5%) than with other forms of induction or spontaneous labor. Hyperstimulation occurred significantly more often with vaginal misoprostol crushed tablet (7.9%) and vaginal misoprostol intact tablet (7.6%) than with crushed oral misoprostol (1.0%) (P =.016 and.018, respectively). There was a shorter time to tachysystole with increasing doses of vaginal misoprostol tablet (P =.01). CONCLUSION: The incidence of tachysystole and hyperstimulation, and time to tachysystole, varied depending on the route and form of misoprostol given.

Administration, Intravaginal↗