Category Archives: Fetal Monitoring

Can you feel a uterine rupture with an epidural?

woman-laboring-hospitalSome care providers discourage epidurals in VBAC moms fearing that it will mask the symptoms of uterine rupture (namely abdominal pain) and delay diagnosis resulting in a poor outcome for baby and to a lesser extent, mom  Other care providers suggest or even require VBAC moms to have an epidural so that a cesarean can quickly take place if needed.  Which philosophy does the evidence support?

Review of 14 VBAC studies

I recently came across a study entitled “The Role of Epidural Anesthesia in Trial of Labor” (Johnson, 1990) that reviewed 14 VBAC studies.  Johnson found among scarred women who ruptured, a greater percentage of women with epidurals reported abdominal pain than women without epidurals.

  • 5 of 14 (35.7%) patients with an epidural who ruptured had abdominal pain.
  • 4 of 23 (17.4%) patients without an epidural who ruptured had abdominal pain.

Interestingly, only 22% of the women who ruptured in that study reported abdominal pain and Johnson concluded, “Thus abdominal pain is an unreliable sign of complete uterine rupture.”  But is it?  69% of women in Zwart (2009) reported abdominal pain. (I write about Zwart here and here.)

One difference between the studies is Zwart included significantly more scarred moms than Johnson: 26,000 versus 10,976.  The second different is that Zwart also included 332,000 unscarred women representing 93% of the sample population.

Unscarred moms, uterine rupture, and abdominal pain

I’m curious if the reason why Zwart reported such a high level of abdominal pain was because it included so many unscarred moms.  I wonder if unscarred moms are more likely to report pain and if so, why would that be.  Zwart combines the symptoms for scarred and unscarred rupture into one chart.  If they broke that chart out by scarred vs. unscarred rupture symptoms, would we see any major differences? Generally, unscarred rupture does more damage to the uterus and is more likely to result in an infant death (Zwart, 2009), so maybe because there is more damage, women report more abdominal pain?

Most common UR symptom: fetal heart tone abnormalities

I checked out  eMedicine’s article “Uterine Rupture in Pregnancy” and was fascinated to learn that several studies concur with Johnson.  They also found that abdominal pain is reported at a much lower rate than fetal distress/ abnormal fetal heart tones:

…sudden or atypical maternal abdominal pain occurs more rarely than do decelerations or bradycardia. In 9 studies from 1980-2002, abdominal pain occurred in 13-60% of cases of uterine rupture. In a review of 10,967 patients undergoing a TOL, only 22% of complete uterine ruptures presented with abdominal pain and 76% presented with signs of fetal distress diagnosed by continuous electronic fetal monitoring. [This is the Jonhson study.]

Moreover, in a study by Bujold and Gauthier, abdominal pain was the first sign of rupture in only 5% of patients and occurred in women who developed uterine rupture without epidural analgesia but not in women who received an epidural block.  (Bujold E, Gauthier RJ. Neonatal morbidity associated with uterine rupture: what are the risk factors?. Am J Obstet Gynecol. Feb 2002;186(2):311-4).  Thus, abdominal pain is an unreliable and uncommon sign of uterine rupture. Initial concerns that epidural anesthesia might mask the pain caused by uterine rupture have not been verified and there have been no reports of epidural anesthesia delaying the diagnosis of uterine rupture.

A 2012 study out of the UK (Fitzpatrick, 2012) also reported that 76% of uterine ruptures were accompanied by fetal heart rate abnormalities in comparison to 49% reporting abdominal pain.

ACOG’s stance on epidurals

It’s important to note that ACOG does support the use of epidurals in VBACs:

Epidural analgesia for labor may be used as part of TOLAC, and adequate pain relief may encourage more women to choose TOLAC (109, 110). No high quality evidence suggests that epidural analgesia is a causal risk factor for an unsuccessful TOLAC (44, 110, 111). In addition, effective regional analgesia should not be expected to mask signs and symptoms of uterine rupture, particularly because the most common sign of rupture is fetal heart tracing abnormalities (24, 112).

Remember that fetal heart tracing abnormalities were detected in 76% of the ruptures in Johnson ad 67% of the ruptures in Zwart.

I couldn’t find any mention of epidurals masking rupture pain in the Guise 2010 Evidence Report, but found that the Johnson study was excluded from their report because “No full-text paper, opinion or letter with no data.”  Interesting.

Uterine rupture symptoms

A list of uterine rupture symptoms and their frequency per Medscape’s article on uterine rupture.

  • “80% Prolonged deceleration in fetal heart rate or bradycardia
  • 54% Abnormal pattern in fetal heart rate
  • 40% Uterine hyper-stimulation
  • 37% Vaginal bleeding
  • 26% Abdominal pain
  • 4% Loss of intrauterine pressure or cessation of contractions”

A couple notes.  One, abdominal pain is not a consistent or reliable symptom of UR.  Two, there is a level of interpretation that goes into diagnosing abnormal fetal heart tones even among people who have extensive medical training.

Additional symptoms that I have collected from other sources include:

  • Baby’s head moves back up birth canal
  • Bulge in the abdomen or under the pubic bone (where the baby may be coming through the tear in the uterus)
  • Uterus becomes soft
  • Shoulder pain

Risks and benefits of epidurals

As with every option available to you regarding birth, it’s always good to be knowledgeable on the risks and benefits of epidurals so you can make an informed choice.  Three excellent resources are this article by Sarah Buckley MD, the PubMed Health Epidural Fact Sheet and this review of epidural research by the Cochrane Library.

Take home message

The limited information available tells us that epidurals do not mask abdominal pain from uterine rupture.

The most common symptom of uterine rupture is fetal distress diagnosed by fetal heart rate abnormalities.

Epidurals may be used during a trial of labor after cesarean per ACOG.

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As always, if you can offer further research or perspective on this topic, please leave a comment.  Our knowledge is constantly growing and we can only work with the best information available to us now.  Who knows what future research will tell us?

Do intrauterine pressure catheters make VBAC safer?

A mom planning a VBA1C (vaginal birth after one cesarean) at a Southern California Kaiser recently emailed me. She discovered while interviewing her care provider and asking how they treat VBAC labors differently than non-VBAC labors (an excellent question), that they require intrauterine pressure catheters (IUPC) in all VBAC labors. She wanted to know what I thought of their policy.

As I read more and more about IUPCs, I was increasingly curious why they would be required.  The evidence for their ability to predict uterine rupture is lacking and as a result major OB/GYN associations do not endorse their use in VBAC labors.  Below you will find the recommendations of the American College of Obstetricians and Gynecologists (ACOG), the Royal College of Obstetricians and Gynaecologists (RCOG aka Canada’s ACOG), abstracts of the studies they reference, as well as questions to ask your care provider if they require IUPCs.  As I find more info, I’ll update this page.

What is an IUPC?

WebMD describes it as “a small catheter that is placed along side the baby [that] measures the strength and duration of contractions.”

In order for the IUPC to be inserted next to the baby in the uterus, the fetal membranes must be ruptured and the cervix dilated to at least 1-2cm (UptoDate, 2011).  I suspect that this greatly, if not entirely, limits mom’s ability to move during labor depending on the policies of the hospital and care provider. This also increases the risk of infection and puts mom on the clock in terms of how long her care provider/hospital permits her to labor once her water has been broken.

Do professional obstetrical associations recommend IUPCs in VBACs?

While trying to find if IUPCs were helpful in labor, particularly in diagnosing uterine ruptures, the National Guideline Clearinghouse (2011) gave me a good starting point:

With regard to intrauterine pressure catheters, RCOG notes that their routine use in the early detection of uterine scar rupture is not recommended. ACOG similarly states that no data suggest that intrauterine pressure catheters are superior to external forms of monitoring, and there is evidence that their use does not assist in the diagnosis of uterine rupture.

What does ACOG say about IUPCs?

As I was interested in the exact language used in ACOG’s (2010) VBAC guidelines, I looked it up and found this:

No data suggest that intrauterine pressure catheters or fetal scalp electrodes are superior to external forms of monitoring, and there is evidence that the use of intrauterine pressure catheters does not assist in the diagnosis of uterine rupture.

What IUPC VBAC studies does ACOG reference?

ACOG cites only two studies in that paragraph. The first was published 18 years before ACOG’s recommendations where released and the second, 21 years before. If these are the best studies ACOG can find, then I’m left thinking that there are not many high quality studies on IUPC through 2010.

The first study cited was Devoe (1992) which concluded (emphasis mine),

Though intrauterine monitoring was brief, this model allows a unique view of ‘controlled’ uterine rupture. Spontaneous uterine rupture may evolve more gradually; however, neither catheter type [fluid-filled or solid] would be likely to aid its early recognition.

The second study was Rodriguez (1989) which found (emphasis mine):

The usefulness of the intrauterine pressure catheter in the diagnosis of uterine rupture was assessed by review of 76 cases of uterine rupture, 39 of which were monitored with an intrauterine pressure catheter. The classic description of a loss of intrauterine pressure or cessation of labor was not observed in any of the patients. However, an increase in baseline intrauterine pressure was observed in four patients with an intrauterine pressure catheter. The increase in pressure was associated with severe variable decelerations such that by itself the intrauterine pressure catheter added little to the diagnosis of uterine rupture.

What does RCOG say about IUPCs?

Then I looked up RCOG’s (2007) VBAC guidelines and it stated (emphasis mine):

The routine use of intrauterine pressure catheters in the early detection of uterine scar rupture is not recommended. Observational studies, with varying methodology and case mix, have shown that intrauterine pressure catheters may not always be reliable and are unlikely to add significant additional ability to predict uterine rupture over clinical and CTG surveillance. Intrauterine catheter insertion may also be associated with risk. Some clinicians may prefer to use intrauterine pressure catheters in special circumstances (such as in women who are obese, to limit the risk of uterine hyperstimulation); this should be a consultant-led decision.

What IUPC VBAC studies does RCOG reference?

RCOG cites four studies in that paragraph. Again, it’s surprising that these studies were published 15 – 25 years before the 2007 RCOG guidelines.

First, Arulkumaran (1992) which I found so interesting, I included the entire abstract (emphasis mine):

To evaluate the symptoms and signs of scar rupture with special reference to intrauterine pressure measurement a retrospective analysis of labour records of those women who had trial of labour with a previous Caesarean scar in the National University Hospital over a period of 6 years (1985-1990) was carried out. Known symptoms and signs associated with scar rupture, cardiotocographic tracings and fetal and maternal outcome in these patients were studied. Of the 1,018 women with previous Caesarean scar (4.2% of our pregnant population at term) 722 (70.9%) had trial of labour; 70% delivered vaginally. There were 4 (0.55%) incomplete and 5 (0.69%) complete scar ruptures. All 9 women had an oxytocin infusion; 3 were diagnosed postdelivery (all 3 had complete ruptures); 3 of the 6 who had rupture prior to delivery had sudden reduction in uterine activity, 1 had scar pain and prolonged bradycardia and 2 had no symptoms or signs. Continuous cardiotocography with intrauterine pressure measurements may help to identify scar rupture early and may be of value especially in those who have an oxytocin infusion.

Second, Beckley(1991) whose abstract doesn’t give us much information:

A series of 12 trials of scar associated with scar rupture is reviewed. Uterine activity patterns were assessable in 10 of them. Clinical features and characteristics of the intrauterine pressure waveform and uterine activity are discussed in relation to the integrity of the scar.

The third study RCOG cited was Rodriguez (1989) which ACOG also cited and I previously shared.

Fourth, Madanes (1982) whose abstract also is lacking any conclusions or major findings:

A case of uterine perforation by an intrauterine pressure catheter is described. Five similar cases from the literature are reviewed. A revision of the pressure catheter insertion technique is discussed.

Do IUPCs pose any risks to the baby?

I was very disappointed in the overall lack of published research on IUPCs in VBACs. I was further disappointed that there was very little discussion on the specific risks of IUPCs to mom or baby and at what rate these complications occur. I found Wilmink (2008) which discusses the IUPC related complications in two labors resulting in one infant death:

CASES: We describe the placement of an IUPC during induction of labor with oxytocin in two cases, one presenting with a singleton pregnancy and the other a twin pregnancy. After introduction of the IUPC, both cases were complicated by blood loss and signs of fetal distress on cardiotocography. An emergency cesarean section was performed in both cases. In the first case, extramembranous placement of the IUPC was observed, whereas in the second case, the IUPC had lacerated an arteriovenous anastomosis in the membranes, resulting in perinatal [infant] death. CONCLUSION: Placement of an intrauterine pressure catheter instead of external tocodynamometry has a small risk for serious fetal complications.

It would be helpful to have a large scale study on IUPCs conducted so we know how frequently complications like this occur.  It’s very difficult to weigh the pros and cons of IUPCs if we don’t fully understand the risks that they pose.  Is it worth mandating the use of IUPCs in VBAC labors if it means that the misplacement of the IUPC could sever the blood, and thus oxygen, supply to baby?

If your care provider requires IUPCs, what questions should you ask?

I posted on my Facebook page requesting the opinion of various midwives and OB/GYNs I know on the use of IUPCs in VBAC labors. Barbara Herrera provided this excellent list of questions:

  1. How will you know if there is a UR [uterine rupture]? What signs are you looking for?
  2. What is the process you go through to know it is a UR and not the IUPC misplacement or falling out?
  3. Who puts the IUPC in? The RN? Or you (the doc)? Who has more experience putting it in?
  4. How do we assure its proper placement?
  5. Will I be able to move about the bed and beside the bed once the IUPC is placed?
  6. If the IUPC registers something is amiss, as long as the FHR [fetal heart rate] is still okay, can I trust those around me not to freak out until we know if it is dislodged or misplaced? (Most women are much more able to move around with the IUPC than the external monitors.)
  7. Will using the IUPC mean I am going to have pitocin augmentation at some point?

The take away message

In light of the fact that

  • ACOG and RCOG do not recommend the use of IUPCs in VBACs as
  • IUPCs have not been proven effective in predicting uterine rupture and as
  • IUPCs can pose risks to babies (including blood loss and signs of fetal distress resulting in emergency cesareans and infant death) at a rate that we do not yet know while
  • requiring the (premature) breaking of fetal membranes (“breaking your water”),
  • increasing the risk of infection, and
  • possibly restricting mom to bed for her labor,

I can’t imagine why any hospital or OB would require their use.*

Elizabeth Allemann, MD left this comment on my Facebook page which I think summed up the issue well:

If a woman has decided to labor and birth with a uterine scar, she’s made her decision. If she wants to be successful, she’ll need what every woman needs to give birth: privacy, love, good nutrition, time, patience, touch, and care by a team that trusts her to give birth. And she’ll need that even more because she’s been scarred–in her heart and soul, not just on her uterus. And we need things to come down and out. An IUPC isn’t going to give her any of that. It’s a sad state of affairs when we can’t provide any of that in the hospital (generally) for any women and we end up forcing women to birth at home, just to get a chance to birth at all. Not that there’s anything wrong with home birth, but if a woman wants to give birth in the hospital, we should be able to provide that for her without a Niagara Falls of interventions waiting to pounce on her.

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* I had a conversation with a friend who teaches Bradley childbirth classes recently. She said that OBs/hospitals use IUPCs because then they can show that they “did everything” to protect the mom from uterine rupture and in the event that a UR did occur and they were taken to court, they could bring that information with them. But I responded with the fact that IUPCs have not been proven effective in predicting UR and ACOG/RCOG don’t recommend their use, so I don’t believe that would be a strong enough argument hold up in court.  I’m not an attorney, so I could be completely wrong, but that is what makes sense to my non-legal mind.

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American College of Obstetricians and Gynecologists (ACOG). Vaginal birth after previous cesarean delivery. Washington (DC): American College of Obstetricians and Gynecologists (ACOG); 2010 Aug. 14 p. (ACOG practice bulletin; no. 115).

Arulkumaran S, Chua S, Ratnam SS. Symptoms and signs with scar rupture: value of uterine activity measurements. Aust N Z J Obstet Gynaecol 1992;32:208–12.

Beckley S, Gee H, Newton JR. Scar rupture in labour after previous lower uterine segment caesarean section: the role of uterine activity measurement. Br J Obstet Gynaecol 1991;98: 265–9.

Devoe LD, Croom CS, Youssef AA, Murray C. The prediction of “controlled” uterine rupture by the use of intrauterine pressure catheters. Obstet Gynecol 1992; 80:626-9. (Level II-2)

Lucidi RS, Chez RA, Creasy RK. The clinical use of intrauterine pressure catheters. J Matern Fetal Med. 2001 Dec;10(6):420-2. Review. PubMed PMID: 11798454.

Madanes AE, David D, Cetrulo C. Major complications associated with intrauterine pressure monitoring. Obstet Gynecol 1982;59: 389–91.

National Guideline Clearinghouse (NGC). Guideline synthesis: Vaginal birth after cesarean (VBAC). In: National Guideline Clearinghouse (NGC) [Web site]. Rockville (MD): 2011 Jan. [cited YYYY Mon DD]. Available: http://www.guideline.gov.

Royal College of Obstetricians and Gynaecologists (RCOG). Birth after previous caesarean birth. London (UK): Royal College of Obstetricians and Gynaecologists (RCOG); 2007 Feb. 17 p. (Green-top guideline; no. 45).

Rodriguez MH, Masaki DI, Phelan JP, Diaz FG. Uterine rupture: are intrauterine pressure catheters useful in the diagnosis? Am J Obstet Gynecol 1989; 161:666-9. (Level III)

Wilmink FA, Wilms FF, Heydanus R, Mol BW, Papatsonis DN. Fetal complications after placement of an intrauterine pressure catheter: a report of two cases and review of the literature. J Matern Fetal Neonatal Med. 2008 Dec;21(12):880-3.

The Role of Interpretation – ACOG Refines Fetal Heart Rate Monitoring Guidelines

Photo credit: http://healthmad.com/health/fetal-monitoring/

Photo credit: http://healthmad.com/health/fetal-monitoring/

I remember when I was pregnant with my first.  The CNM I hired worked at multiple hospitals, so my husband and I toured each one to get a feel for each hospital’s standard policies and procedures.  A few people I knew questioned why we were bothering doing this since, aren’t all hospitals the same?  While I was expecting some differences, I was really surprised with what I found.

The standard procedures of the three hospitals we toured varied greatly – everything from the use of telemetry (wireless fetal) monitoring to how much bonding time a mom and baby were permitted before baby was whisked away for mandatory hospital procedures to where babies slept at night and whether babies were routinely given sugar water, formula or a pacifier.

I came away realizing how important it is to carefully screen which hospital you chose as well as your OB/midwife and the L&D nurse who will be caring for you during your stay at the hospital.

This June 22, 2009 press release illustrates ACOG’s (The American College of Obstetricians and Gynecologists’) efforts to help standardize the care women receive from OBs.  Specifically, they wish to stabilize the variability in fetal heart rate interpretations which could considerably impact the frequency of the “fetal distress” diagnosis.

EFM refers to external fetal monitoring which most women know as the belt laboring women wear that measures the baby’s heart rate and is connected to a machine which produces a strip of the baby’s heart rate as well as mom’s contractions.

I found these quotes of particular interest (emphasis is mine).

“Since 1980, the use of EFM has grown dramatically, from being used on 45% of pregnant women in labor to 85% in 2002,” says George A. Macones, MD, who headed the development of the ACOG document. “Although EFM is the most common obstetric procedure today, unfortunately it hasn’t reduced perinatal mortality or the risk of cerebral palsy. In fact, the rate of cerebral palsy has essentially remained the same since World War II despite fetal monitoring and all of our advancements in treatments and interventions.”

“Our goal with the ACOG guidelines was to define existing terminology and narrow definitions and categories so that everyone is on the same page,” says Dr. Macones. One of the problems with FHR tracings is the variability in how they’re interpreted by different people. The ACOG guidelines highlight a case in which four obstetricians examined 50 FHR tracings; they agreed in only 22% of the cases. Two months later, these four physicians reevaluated the same 50 FHR tracings, and they changed their interpretations on nearly one out of every five tracings.

A meta-analysis study shows that although EFM reduced the risk of neonatal seizures, there is still an unrealistic expectation that a nonreassuring FHR can predict the risk of a baby being born with cerebral palsy. The false-positive rate of EFM for predicting cerebral palsy is greater than 99%. This means that out of 1,000 fetuses with nonreassuring readings, only one or two will actually develop cerebral palsy. The guidelines state that women in labor who have high-risk conditions such as preeclampsia, type 1 diabetes, or suspected fetal growth restriction should be monitored continuously during labor.

Note that VBAC is not listed under “high-risk conditions” that “should be monitored continuously during labor.”  Also, with a 99% false positive rate for cerebral palsy, I wonder about the rate of uterine rupture false positives.

Here is the link, ACOG Refines Fetal Heart Rate Monitoring Guidelines.