Research This paper discusses current research regarding fetal heart tone decelerations as they appear on the Electronic Fetal Monitor, unplanned cesarean sections as related to the use of epidural anesthesia, and meconium births.  The focus on each of these topics is defining them, illuminating what current research says about them, and drawing conclusions based on the evidence presented.   The one topic I do not include in this paper that is in the essay paper is precipitous labor.  There is not much research on this topic other than the statistics reported from hospitals regarding what percent of their births qualify for the label since they are less than three hours of active labor (around 4%).   Fetal heart tone decelerations as they appear on the Electronic Fetal Monitor The Electronic Fetal Monitor is a machine used in the hospital setting which, through the use of sensors placed on the laboring mother’s belly, both reads the fetal heart rate and measures the strength and length of the mother’s contractions. When used properly, the Electronic Fetal Monitor is used intermittently at intervals of every two to four hours.  It can provide the parents and providers information about how the baby is responding to contractions just as a Doppler and a manual maternal pulse count does.  It can effectively be used as a tool for confirming suspected problems, or as a tool to allow high risk pregnancy mothers to labor without other interventions for as long as possible.  The physician-inventor of the electronic fetal monitor, Dr. Edward H. Hon, identified several factors that could have an adverse effect on the fetal heart rate, and so made such monitoring seem very desirable: (1)intrinsic fetal disease; (2) placental disease; (3) cord compression; (4) maternal disease; (5) drugs administered for analgesia and anesthesia; and (6) maternal hypotension from the supine position, from conduction anesthesia, or from both (Hon 1974). Many of these factors are either directly generated by or made more dangerous in the hospital, where fetal infections commonly result from too many vaginal exams; where cord compression often results from improper maternal positioning and/or the administration of Pitocin; and where drugs are often pressed on laboring women who otherwise might choose to do without. At a conference on "Crisis in Obstetrics: The Management of Labor," held in New York City in March 1987, Hon himself emphatically stated, "If you mess around with a process that works well 98% of the time, there is much potential for harm....[most women in labor may be] much better off at home [than in the hospital with the electronic fetal monitor]" (Young and Shearer 1987).   Clinicians began questioning the reliability of subjective interpretation of fetal heart tracings soon after EFM went into general use. Thirty years later, a meta-analysis of 12 randomized clinical trials involving 58,855 gravidas cast doubt on the benefits of EFM, which is associated with an increase in operative deliveries as a result of high sensitivity but low specificity in predicting fetal hypoxia and acidosis. (Fetal pulse oximetry: 8 vital questions www.obgmanagement.com) Part of what makes the use of the electronic fetal monitor so questionable is that acceptable degrees of variation in the fetal heart rate have never been firmly established. Throughout labor it is not uncommon for babies to have some or even extreme fluctuations of their heart rate which results in perfectly normal babies born without technological intervention. Several studies have established that continuous external electronic monitoring is no more effective at identifying those fluctuations that do in fact indicate fetal distress than periodic hand-held Doppler checks (Chalmers 1978; Haverkamp and Orleans 1983).  In an attempt to find a way to create a language that OB’s could use as a common way to define what they are reading on the tracings of the electronic fetal monitor,  a study was created which gave 21 multinational experienced obstetricians the same 13 tracings from electronic fetal monitoring.  They were asked to segment and classify the fetal heart tones.  They were also asked to give their interpretation of the fetal heart tones, asses the fetal condition, and propose obstetric management.  The results of this study were that they showed fair agreement on the accelerations, baseline segments, and classifying the decelerations.  They showed poor agreement   when classifying baseline variability and the type of deceleration.  They also showed poor agreement regarding assessment of the fetal condition as well as proposals for obstetric management (what to do).  The study, published in the European Journal of Obstetrics, Gynecology, and Reproductive Biology, concluded that there is a “lack of unequivocal terminology and definitions in the assessment of FHR recordings”.  (European Journal of Obstetrics, Gynecology, and Reproductive Biology 52:21-8) Many parents will face obstetricians who will tell them that the constant use of the electronic fetal monitor helps prevent serious complications.  The research however, shows quite the opposite.  According to Brackbill et al., in four methodologically sound studies carried out to evaluate the effects of electronic monitoring (Banta and Thacker 1979; Haverkamp and Orleans 1983), women in labor were randomly assigned to manually monitored and electronically monitored groups that were comparable in other respects.  The results were the same in all four studies: more electronically monitored women ended up...with Cesarean deliveries. Cesarean section rates ranged between 63% and 314% higher for electronically monitored women than manually monitored women. There was no improvement in perinatal outcome for the babies delivered by Cesarean section. The principal "reasons" alleged for these surgical deliveries--fetal distress and Cephalopelvic Disproportion (disproportion of head to pelvis)--cannot be proved or disproved. The real reasons, according to these studies, are attending physicians' impatience and nervousness. (Brackbill et al. 1984:10)  For many obstetricians and midwives continuous electronic fetal heart rate monitoring during labor has replaced the traditional method of intermittent auscultation, periodic checks on fetal heart rates before, during, and after contractions. Of the eight prospective randomized controlled trials designed to assess its value in obstetric care, four were concerned with mothers defined as being at high-risk, three with normal or low-risk patients, and the eighth with the total population of a maternity hospital over several months. None suggested any major advantage of continuous fetal heart rate monitoring over intermittent surveillance in terms of neonatal mortality, morbidity, cord blood pH values, or the five minute Apgar score. The rates of caesarean section and forceps delivery were higher in the continuously monitored group. “For low-risk mothers here is a good case for a return to the traditional method of intermittent auscultation with its lower false-positive rate, lesser incidence of intervention, and opportunity for greater contact between the maternity care staff and the mother.” (Prentice, A. and T. Lind. 1987. "Fetal heart rate monitoring during labour--too frequent intervention, too little benefit?" Lancet 8572:1375-7.) Unplanned Cesarean Section as Related to the use of Epidurals Many women arrive at the swift conclusion that they will have an epidural based on recommendations from friends who “swear by them”.  Afraid of the pain of labor, they opt out of it, insisting on an epidural as soon as they begin active labor.  They attribute a very low level of sophistication to the procedure and to the medication and assume it can do only good.  Indeed, an investigation into the process shows that from the perspective of the anesthesiologist Superficially, obstetric anesthesia appears to be a simple field with a limited range of interest, but it is a deceptively demanding subspecialty. Not only are two patients involved in each anesthetic administration, but also the dynamic events of normal labor require that the muscles concerned with delivery retain their power and coordination to the full. (Bromage PR. Epidural analgesia. Philadelphia: Saunders, 1978:513) Understanding the complicated and dynamic mixture of anesthesiologist, medicine, catheter placement, combined with the many systems that will be affected in both the mother’s and baby’s bodies provides some insight into why things might not be so clear cut, and even why a “simple” epidural often leads to a waterfall effect of other interventions, including cesarean section.   Research shows clearly that having an epidural will increase a mother’s chances for having a cesarean section.  This is well documented and can be a big eye opener for someone considering an epidural.  For the expectant mother who is sure she will want an epidural, the fact that the later in labor she receives the epidural, the less and less likely it will lead to a cesarean section is pertinent information (Thorp JA, Meyer BA, Cohen GR et al . Epidural analgesia in labor and cesarean delivery for dystocia. Obstet Gynecol Surv 1994;49:362-9.).  Therefore, any work a childbirth educator or doula can do with this woman to get her to “buy in” to laboring until after she has passed 5cm will create a positive effect.   The most common cause cited for a cesarean is CPD (Cephalopelvic Disproportion), a condition in which the baby’s head will not “fit” through the birth canal.  In a 1989 study, it was found that three times the number of women had cesareans for CPD in the epidural group (15.8% versus 5.5% for the non-epidural group).  Of remarkable note is that before they were given the epidural, there was no indication that CPD would be a factor in the delivery of any of the women in the study.   (Philipsen T and Jensen NH, EurJ Obstet Gynecol Reprod Biol 1989;30:27:33.) Research does show a consistent increase in Cesarean section rate in women having epidural analgesia. The overall weighted difference in women who received an epidural versus those who did not was 10%.  This means that for every 10 women in labor having epidural analgesia, one more will have a Cesarean section, who would not have done had they had another form of analgesia or none at all. (SC Morton, MS Williams, EB Keeler, JC Gambone, KL Kahn. Effect of epidural analgesia for labor on the Cesarean delivery rate. Obstetrics & Gynecology 1994 83: 1045-52.)  Several retrospective studies consistently demonstrated an association between epidural analgesia and increased durations of both the first and second stages of labor, oxytocin augmentation, instrumental vaginal delivery and cesarean section for dystocia. In these studies, the probability of cesarean section for dystocia was reported to be increased three- to six- fold by the administration of epidural analgesia. (Thorp JA, Parisi VM, Boylan PC, Johnston DA. The effect of continuous epidural analgesia on cesarean section for dystocia in nulliparous women. Am J Obstet Gynecol 1989;161:670-5.) (Thorp JA, Eckert LO, Ang MS, Johnston DA, Peaceman AM, Parisi VM. Epidural analgesia and cesarean section for dystocia: risk factors in nulliparas. Am J Perinatol 1991;8:402-10.) (Lieberman E, Lang JM, Cohen A, D'Agostino R Jr, Datta S, Frigoletto FD Jr. Association of epidural analgesia with cesarean delivery in nulliparas. Obstet Gynecol 1996; 88:993-1000. )  This leads us back to the first quote in this topic from the anesthesiologist’s perspective which says that they have to get all of the medication right and still allow the body to work effectively—a notable task, and one that is not always possible as both the prevention and the remedy for dystocia often lies in position change, which can be impossible for the laboring mother when an epidural is used due to her own ability to use her legs effectively not to mention and some hospital’s protocol which says that she may not try weight-bearing positions once the epidural is in place.   If a labor should be at the control of the laboring mother, then it must be acknowledged that with an epidural, she gives up the ability to control her labor at all.  She faces certain constant monitoring, probable instrument delivery, and the inability to help her body birth her baby by using any of the best known ways to have a speedy and healthy delivery.   She loses the options of a bath or shower for comfort, any nourishment she may need for energy and sustenance, movement to help baby navigate, and position changes to open and release the body.  Although it sounds extreme, we see from research that she is effectively taking on a cesarean section as a not-so-remote possibility for one of her birthing options when she accepts the epidural.   Meconium During labor, it sometimes occurs that the amniotic fluid contains meconium, the baby’s first bowel movement.  The provider defines the meconium as light, moderate, thick, or particulate.  Response to the presence of meconium will depend on the quality of the meconium.   Light meconium is thin and fluid, if it were put into a jar and held up to the light it would be transparent but with a slight green or yellowish tinge.  Moderate meconium has the same coloring but is thicker.  Thick meconium is pasty to touch, more solid than watery, and sticky like mud.  Particulate meconium has the thickness combined with chunky or stringy substances in it.  Much of the research regarding meconium focuses on the proper way to suction it from a baby’s nose and mouth during delivery.  This piece, however, will focus on the presence of meconium and the low rate at which meconium in its thin and moderate forms poses a serious threat to baby, with the goal in mind of helping to prepare expectant mothers and doulas to remain calm and focused on the labor if a meconium delivery occurs.   “Meconium-stained amniotic fluid occurs in approximately 12% of live births.  In approximately one third of these infants meconium is present below the vocal cords.  However, meconium aspiration syndrome [MAS] develops in only 2 out of every 1000 live-born infants.  95% of infants with inhaled meconium clear the lungs spontaneously.” (Katz VL, Bowes, WA Jr., Am  J  Obstet Gynecol 1992 Jan; 166 (1 pt 1):171-83)  While “fetal heart rate monitoring and appropriate fetal acid-base evaluation is recommended for following patients with meconium in the amniotic fluid during labor” (AJOG Jul 1; 122(5):573-80 Miller FC, Sacks DA, Yeh SY, Paul RH, Schifrin BS, Martin CB Jr., Hom EH), the actual presence of meconium without sign of fetal asphyxia “is not a sign of fetal distress and need not be an indication for active intervention” (ibid).   This significant study looked at a total of 366 labors and compared meconium and non-meconium labors to come to this determination.  Several studies confirm what they found, and a midwife on medline points out that looking at other factors will help the provider and parents know a little more about what to expect: Have you got a good FHT pattern?  How about variables?  That’s highly unlikely to cause aspiration…I’d transport if the babe was persistently tachycardic, without a lot of variability, or if there are lates [decelerations].  And this all can be done with a Doppler and some patience.  In 19 years of practice I’ve only taken one lady in [to the hospital] for MAS [ Meconium Aspiration Syndrome]. She (her posting does not list her name)  is illuminating the fact that a meconium baby who will have respiratory problems will present other indicators of these problems than just the meconium.  An American Journal of Obstetrics and Gynecology research article pushes this idea even further by showing that even postdates babies (babies who are overdue) who are generally fretted over because they may be more likely to have meconium births do “have a higher incidence of meconium, [yet] they do not have a higher incidence of asphyxiation than term babies”. (Usher, et al., AJO OB/GYN, Feb 88; and Lender, et al., Journal of Pediatrics, April 88)   If a doula is working with parents who are experiencing a meconium labor that otherwise appears healthy, this research is a tool for conversation which can help lead the laboring mother away from fear and anxiety over the health of her unborn child and back into the process of birthing.   Research regarding fetal heart tone decelerations as they appear on the Electronic Fetal Monitor show that every provider will read the tracings with his or her own subjective perspective and that before decisions are made based on the tracings, parents may want to ask for a second opinion.  Research regarding unplanned cesarean sections as related to the use of epidural anesthesia illuminates the fact that having an epidural increases a mother’s chances for a cesarean section, especially if she gets one before solid labor has been established.  Research about meconium births can provide parents and doulas with confidence that most meconium cases do not result in poor fetal outcome.
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