Perils of the new labor management guidelines Cohen, Wayne R., MD; Friedman, Emanuel A., Med ScD
American journal of obstetrics and gynecology,
04/2015, Letnik:
212, Številka:
4
Journal Article
Recenzirano
Recent guidelines issued jointly by the American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine for assessing labor progress differ substantially from those ...described initially by Friedman, which have guided clinical practice for decades. The guidelines are based on results obtained from new and untested methods of analyzing patterns of cervical dilatation and fetal descent. Before these new guidelines are adopted into clinical practice, the results obtained by these unconventional analytic approaches should be validated and shown to be superior, or at least equivalent, to currently accepted standards. The new guidelines indicate the patterns of labor originally described by Friedman are incorrect and, further, are inapplicable to modern obstetric practice. We contend that the original descriptions of normal and abnormal labor progress, which were based on direct clinical observations, accurately describe progress in dilatation and descent, and that the differences reported more recently are likely attributable to patient selection and the potential inaccuracy of very high-order polynomial curve-fitting methods. The clinical evaluation of labor is a process of serially estimating the likelihood of a safe vaginal delivery. Because many factors contribute to that likelihood, such as cranial molding, head position and attitude, and the bony architecture and capacity of the pelvis, graphic labor patterns should never be used in isolation. The new guidelines are based heavily on unvalidated notions of labor progress and ignore clinical parameters that should remain cornerstones of intrapartum decision-making.
Clinical assessment of uterine contractions Cohen, Wayne R.
International journal of gynecology and obstetrics,
November 2017, 2017-Nov, 2017-11-00, 20171101, Letnik:
139, Številka:
2
Journal Article
Recenzirano
The assessment of uterine contractions is important in clinical decision‐making, but the precise role for appraising contractions remains controversial. Four clinical approaches to assessing ...contractions are available: manual palpation; intrauterine pressure determination; external tocodynamometry; and electrohysterography. Palpation is inexpensive and harmless but requires the constant bedside presence of a trained observer. Intrauterine pressure measurement is considered the most sensitive and specific technique, and has become the standard by which other methods are judged; however, its quantitative measurements are not always precise or reproducible. Moreover, the availability of intrauterine pressure measurements does not seem to improve maternal or neonatal outcomes in most situations. External tocodynamometry is the most widely used technique. It is easy to apply and provides reasonably accurate information about the frequency and duration of contractions, but not their amplitude. It can require frequent adjustment during labor and might not work well in patients who are obese. Electrohysterography is a recently available noninvasive technology that detects uterine electrical activity using electrodes placed on the mother's abdominal wall. This approach is at least as reliable and accurate as tocodynamometry.
Techniques for assessing contractions present different advantages and limitations. Intrauterine pressure reflects labor progress unreliably; electrohysterography is well placed to become the standard technique.
The latent phase of labor Cohen, Wayne R.; Friedman, Emanuel A.
American journal of obstetrics and gynecology,
20/May , Letnik:
228, Številka:
5
Journal Article
Recenzirano
Odprti dostop
The latent phase of labor extends from the initiation of labor to the onset of the active phase. Because neither margin is always precisely identifiable, the duration of the latent phase often can ...only be estimated. During this phase, the cervix undergoes a process of rapid remodeling, which may have begun gradually weeks before. As a consequence of extensive changes in its collagen and ground substance, the cervix softens, becomes thinner and dramatically more compliant, and may dilate modestly. All of these changes prepare the cervix for the more rapid dilatation that will occur during the active phase to follow. For the clinician, it is important to recognize that the latent phase may normally extend for many hours. The normal limit for the duration of the latent phase should be considered to be approximately 20 hours in a nullipara and 14 hours in a multipara. Factors that have been associated with a prolonged latent phase include deficient prelabor or intrapartum cervical remodeling, excessive maternal analgesia or anesthesia, maternal obesity, and chorioamnionitis. Approximately 10% of women with a prolonged latent phase are actually in false labor, and their contractions eventually abate spontaneously. The management of a prolonged latent phase involves either augmenting uterine activity with oxytocin or providing a sedative-induced period of maternal rest. Both are equally effective in advancing the labor to active phase dilatation. A very long latent phase may be a harbinger of other labor dysfunctions.
The objective of this study was to compare performance of a maternal surface electrode patch with ultrasound- and tocodynamometer-based monitoring to detect fetal heart rate and uterine contractility ...in late preterm labors.
Thirty women between 34
and 36
weeks' gestation were monitored simultaneously with a Doppler/tocodynamometer system and a wireless fetal-maternal abdominal surface electrode system. Fetal and maternal heart rate and uterine contraction data from both systems were compared. Reliability was measured by the success rate and percent agreement. Deming regression and Bland-Altman analysis estimated the concordance between the systems. Uterine contractions were assessed by visual interpretation of monitor tracings.
The success rate for the surface electrode system was 89.5% (95% confidence interval CI, 85.7-93.3), and for ultrasound it was 88.4% (95% CI, 84.9-91.9;
= 0.73), with a percent agreement of 88.1% (95% CI, 84.2-92.8). Results were uninfluenced by the patients' body mass. The mean Deming slope was 1 and the y-intercept was -3.0 beats per minute (bpm). Bland-Altman plots also showed a close relationship between the methods, with limits of agreement less than 10 bpm. The percent agreement for maternal heart rate was 98.2% (95% CI, 97.4-98.8), and for uterine contraction detection it was 89.5% (95% CI, 85.5-93.4).
Fetal heart rate and uterine contraction monitoring at 34
to 36
weeks using abdominal surface electrodes was not inferior to Doppler ultrasound/tocodynamometry for fetal-maternal assessment.
clinicaltrials.gov/February 20, 2017/identifier NCT03057275.
· Monitoring the preterm fetal heart rate with surface electrodes is feasible.. · Preterm contractions can be monitored with surface electrodes.. · The technique was noninferior to standard external monitors..
The second stage of labor Cohen, Wayne R.; Friedman, Emanuel A.
American journal of obstetrics and gynecology,
March 2024, 2024-Mar, 2024-03-00, 20240301, Letnik:
230, Številka:
3
Journal Article
Recenzirano
Odprti dostop
The second stage of labor extends from complete cervical dilatation to delivery. During this stage, descent and rotation of the presenting part occur as the fetus passively negotiates its passage ...through the birth canal. Generally, descent begins during the deceleration phase of dilatation as the cervix is drawn upward around the fetal presenting part. The most common means of assessing the normality of the second stage of labor is to measure its duration, but progress can be more meaningfully gauged by measuring the change in fetal station as a function of time. Accurate clinical identification and evaluation of differences in patterns of fetal descent are necessary to assess second stage of labor progress and to make reasoned judgments about the need for intervention. Three distinct graphic abnormalities of the second stage of labor can be identified: protracted descent, arrest of descent, and failure of descent. All abnormalities have a strong association with cephalopelvic disproportion but may also occur in the presence of maternal obesity, uterine infection, excessive sedation, and fetal malpositions. Interpretation of the progress of fetal descent must be made in the context of other clinically discernable events and observations. These include fetal size, position, attitude, and degree of cranial molding and related evaluations of pelvic architecture and capacity to accommodate the fetus, uterine contractility, and fetal well-being. Oxytocin infusion can often resolve an arrest or failure of descent or a protracted descent caused by an inhibitory factor, such as a dense neuraxial block. It should be used only if thorough assessment of fetopelvic relationships reveals a low probability of cephalopelvic disproportion. The value of forced Valsalva pushing, fundal pressure, and routine episiotomy has been questioned. They should be used selectively and where indicated.
The active phase of labor Friedman, Emanuel A.; Cohen, Wayne R.
American journal of obstetrics and gynecology,
20/May , Letnik:
228, Številka:
5
Journal Article
Recenzirano
Odprti dostop
The active phase of labor begins at various degrees of dilatation when the rate of dilatation transitions from the relatively flat slope of the latent phase to a more rapid slope. No diagnostic ...manifestations demarcate its onset, other than accelerating dilatation. It ends with apparent slowing of dilatation, a deceleration phase, which is usually short in duration and frequently undetected. Several aberrant labor patterns can be detected during the active phase, including protracted dilatation, arrest of dilatation, prolonged deceleration phase and failure of descent. Underlying factors may include cephalopelvic disproportion, excessive neuraxial block, poor uterine contractility, fetal malpositions, malpresentations, uterine infection, maternal obesity, advanced maternal age and previous cesarean delivery. When an active-phase disorder is identified, cesarean delivery is justifiable if there is compelling clinical evidence of disproportion. A prolonged deceleration disorder is strongly associated with disproportion and second stage abnormalities. Shoulder dystocia may occur if vaginal delivery eventuates. This review discusses several issues raised by the introduction of new clinical practice guidelines for labor management.
There is no doubt that parturition can produce fetal and neonatal adversity, but the frequency with which this occurs is uncertain, particularly in modern healthcare settings. Moreover, there is a ...paucity of recent studies in this area. Substantial challenges impede epidemiologic study of the effect of parturition on offspring. Randomized trials would be ethically fraught. Therefore, large observational samples with detailed data concerning labor and delivery events are needed. Importantly, long-term follow-up of infants is necessary to reach reliable conclusions. Few such data sets exist, and it is difficult, expensive, and time-consuming to create and to study them. Reports of immediate newborn condition in relation to the antecedent labor are helpful, but this evidence is an imperfect predictor of long-term neurologic status. In this review, we endeavor to summarize existing information about the relationship between objectively defined abnormalities of labor progress and long-term disability in offspring. The only data available are from collected experiential information on outcomes stratified according to labor and delivery events. Most studies do not ensure against confounding by the many concurrent conditions that may affect outcome, or use inconsistent criteria to define abnormal labor. According to the best available evidence, dysfunctional labor patterns are potentially associated with poor outcomes for surviving infants. The question of whether these adverse effects can be mitigated by early diagnosis and expeditious management deserves to be answered, but cannot be at this time. In the absence of more conclusive results from well-designed studies, we can conclude that the best interests of offspring are served by adhering to evidence-based paradigms for the prompt identification and treatment of dysfunctional labor patterns.
Misguided guidelines for managing labor Cohen, Wayne R., MD; Friedman, Emanuel A., MD, Med ScD
American journal of obstetrics and gynecology,
06/2015, Letnik:
212, Številka:
6
Journal Article
Recenzirano
In a recent review we expressed concerns about new guidelines for the assessment and management of labor recommended jointly by the American Congress of Obstetricians and Gynecologists (ACOG) and the ...Society for Maternal-Fetal Medicine (SMFM). These guidelines are based heavily on a new concept of how cervical dilatation and fetal descent progress, derived from the work of Zhang et al. In their Viewpoint article they have addressed, but not allayed, the concerns we described in our review. We assert that the dilatation curve promulgated by Zhang et al cannot be reconciled with direct clinical observation. Even if they were correct, however, it still does not follow that the ACOG/SMFM guidelines should recommend replacing the coherent system of identifying and managing labor aberrations described by Friedman. That system is grounded in well-established clinical principles based on decades of use and the objectively documented association of some labor abnormalities with poor fetal and maternal outcomes. Recommendations for new clinical management protocols should require the demonstration of superior outcomes through extensive, preferably prospective, assessment. Using untested guidelines for the management of labor may adversely affect women and children. Even if those guidelines were to reduce the currently excessive cesarean delivery rate, the price of that benefit is likely to be a trade-off in harm to parturients and their offspring. The nature and degree of that harm needs to be documented before considering adoption of the guidelines.
Are the Labor Management Guidelines evidence based? Friedman, Emanuel A.; Cohen, Wayne R.
American journal of obstetrics and gynecology,
April 2022, 2022-Apr, 2022-04-00, 20220401, Letnik:
226, Številka:
4
Journal Article
