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Clinical Reviews


Preserving the option of vacuum extraction: 5 experts tell why and how

In properly selected cases, vacuum extraction or forceps delivery may be the best option for the patient, but declining usage rates threaten their availability.

February 2004 · Vol. 16, No. 2

KEY POINTS

  • Operative vaginal deliveries have been declining overall, and the ratio of vacuum to forceps deliveries has increased.
  • Avoid forceps rotations exceeding 45° and do not attempt to forcibly rotate the head with a vacuum device because of the potential for injury and litigation.
  • The best candidates for operative vaginal delivery have a prolonged second stage of labor or non-reassuring fetal status, the fetal head at the outlet or low in the pelvis, and a functioning epidural.
  • Avoid sequential use of vacuum and forceps.

 

Panelists

Neal M. Lonky, MD, MPH, moderator of this discussion, is director of medical education and colposcopic services, department of obstetrics and gynecology, Kaiser Permanente, Orange County, Calif. He serves on the board of directors, Southern California Permanente Group, and is clinical professor of obstetrics and gynecology at the University of California, Irvine. He is an OBG Management contributing editor.

James A. Bofill, MD, is associate professor, division of maternal-fetal medicine, University of Mississippi Medical Center, Jackson, Miss.

Thomas Garite, MD, is E.J. Quilligan Professor and chair, obstetrics and gynecology, University of California, Irvine.

Robert Hayashi, MD, is J. Robert Willson Professor of obstetrics and director, division of maternal-fetal medicine, University of Michigan, Ann Arbor, Mich.

Victor L. Vines, MD, is in private practice, Medical City Dallas Hospital, Dallas, Tex. He serves on the physician advisory board for the Perinatal Safety Initiative of the Hospital Corporation of America and is clinical associate professor of obstetrics and gynecology at the University of Texas Southwestern Medical Center, Dallas.

Operative vaginal deliveries are on the wane, even though they may produce the best outcomes in some cases. The reasons? Fear of litigation, patient resistance, and diminishing numbers of experienced physicians. OBG Management convened a panel of experts from a variety of practice settings to address the challenge of offering vacuum and forceps appropriately when external forces discourage their use. Our panelists discuss patient selection, sequential use of vacuum and forceps, and the need to use universal documentation terminology consistently.

Why vacuum and forceps are losing favor

LONKY: Operative vaginal deliveries have declined over the past 2 decades as cesarean section rates have increased. What factors are responsible for the shift?

VINES: Some of our colleagues believe operative delivery should no longer be performed. Although this view is based more on fear of litigation than any scientific basis, we are seeing a downturn in forceps and vacuum deliveries in response, although the proportion of vacuum deliveries has increased notably.

A California study1 of more than half a million women found that about 13% of deliveries were operative. In a Washington study2 on sequential use of vacuum and forceps, the operative delivery rate was 14.4%. Both investigations gathered data from the late 1980s to late 1990s. Perhaps there has been a drop more recently, but Hospital Corporation of America (HCA) data suggest an operative delivery rate of 12% to 14%—mostly vacuum.

BOFILL: The best report on regional differences3 demonstrated that the rate of operative vaginal delivery and even cesarean is much higher in the Southeast than in the rest of the country.

Fear of litigation starts a vicious cycle. As for whether operative vaginal deliveries are declining overall, Yeomans and Hankins4 describe a vicious cycle in which fear of litigation leads to less teaching, which leads to less use of forceps and vacuum, which leads to more bad outcomes—because of meager training—which leads to more litigation.

In our hospital, operative vaginal delivery rates have dropped from about 16% to approximately 12%.

GARITE: The ratio of vacuum deliveries to forceps is changing most dramatically.

Vacuum injuries increase as vacuum displaces forceps

VINES: The number of vacuum-related injuries has increased because the frequency of vacuum and forceps deliveries has reversed. The incidence hasn’t necessarily gone up, but the absolute numbers have, and that has prompted critical review.

LONKY: At Kaiser Permanente on the West Coast, there has been a dramatic shift to the vacuum over the forceps. When I completed my training in 1986, I probably performed forceps and vacuum deliveries at equal rates. Now I may do 1 forceps delivery a year.

HAYASHI: Other factors are early descriptive studies that implicated operative deliveries as the cause of poor outcomes in infants. Although those studies were of poor quality, they influenced physician behavior.

A growing base of studies on the effects of operative delivery on pelvic floor function also has contributed.

The ease, safety, and acceptance of cesarean birth has also played a role in diminishing operative vaginal deliveries, as has the increasing number of women trainees, many of whom feel they lack adequate strength to pull forceps effectively to deliver the fetal head.

Fewer procedures performed means fewer training opportunities

LONKY: Do training programs have an obligation to provide ample opportunity to train in operative vaginal delivery?

HAYASHI: Yes. They are obliged to teach operative delivery whenever the opportunity presents itself. I would say 20 procedures would be “ample” to teach outlet deliveries, while 30 or more would be needed for the more difficult low outlet deliveries involving rotation.

GARITE: Yeomans and Hankins4 mention that, as the number of operative deliveries goes down, the number of physicians with the expertise to train new physicians goes down as well. In our teaching hospital, we have problems not only in gathering an adequate volume of good candidates for operative delivery, but in finding teachers who are comfortable teaching use of forceps.

VINES: In Dallas, we have a regular influx of new physicians trained in residency programs with limited or nonexistent exposure to vacuum. These doctors join groups where partners frequently use vacuum, and many of them—myself included—are essentially self-taught. We try to rectify that by providing hands-on experience with the vacuum, as well as the opportunity to learn from mentors.

‘Flight simulator’ would aid training. Here’s a proposal: Since there is limited opportunity to teach reproducible skills in the vacuum or forceps, we might create a simulator where operative devices could be applied to “fetal heads,” which could be programmed for different positions, stations, or orientations. Pilots learn to handle wind shear and other hazardous but infrequent situations in a simulator—not by practicing in actual wind shear.

BOFILL: That would be a great resource, but it would be costly to develop a truly appropriate model, and we would have to interest bioengineers in building a system.

GARITE: And while we have more and more technological opportunities, which cost more and more money, we have less and less funding available in academic departments.

Patient selection

LONKY: Developing the expertise to perform the procedure is only half the picture. The other is choosing the right candidate (TABLE). In what clinical scenarios is operative vaginal delivery the best choice?

One of the biggest problems with fetal heart rate monitoring is overreaction to cord compression patterns.

HAYASHI: These situations:

  1. An exhausted patient in a protracted second stage of labor. The well-flexed fetal head is at +4 station, occiput-anterior position. This is essentially an outlet, “lift-out” situation.
  2. A patient with adequate clinical pelvimetry who is becoming exhausted at 3 hours with epidural and in whom the fetus is occiputposterior at +4 station.
  3. A patient with adequate clinical pelvimetry and a transverse arrest, 3 hours with epidural, at +2 station.
  4. A patient with worrisome or nonreassuring fetal heart rate deceleration with the fetal head at a low station—ie, +2 to +4.

The last 3 scenarios would involve a trial of operative vaginal delivery.

TABLE

ACOG criteria for types of forceps deliveries

Outlet forceps

  • Scalp is visible at the introitus without separating labia.
  • Fetal skull has reached pelvic floor.
  • Sagittal suture is in anteroposterior diameter or right or left occiput anterior or posterior position.
  • Fetal head is at or on perineum.
  • Rotation does not exceed 45°.

Low forceps

  • Leading point of fetal skull is at station +2 cm and not on the pelvic floor.
  • Rotation is 45° or less (left or right occiput anterior to occiput anterior, or left or right occiput posterior to occiput posterior).
  • Rotation is greater than 45°.

Midforceps

  • Station is above +2 cm but head is engaged.

High forceps

  • Not included in classification.

Reprinted with permission from: American College of Obstetricians and Gynecologists. Operative Vaginal Delivery. ACOG Practice Bulletin No. 17. Washington, DC © ACOG, 2000.

Should ‘difficult’ operative vaginal deliveries ever be performed?

VINES: Several respected lecturers and researchers are teaching that “difficult” operative vaginal deliveries should not be performed. Dr. Steven Clark from Utah and Dr. Jeff Phelan from California say we should perform easy vaginal deliveries or easy cesarean sections. And Dr. Gary Hankins has steered us away from forceps deliveries that involve more than 45° of rotation.

Yet I believe some patients still should be delivered via operative technique. For example, in rotational deliveries (occiput transverse and occiput posterior), Dr. Aldo Vacca has presented compelling evidence that, when the vacuum is placed on the correct point of the fetal head (the flexion point) and given correct axis traction, 90% or more will autorotate to an occiput-anterior position and deliver.

HAYASHI: We are entering a time when operative vaginal delivery for rotations of more than 45° will be abandoned, for fear of litigation.

GARITE: I agree that acceptance of rotational vaginal deliveries has ended. Defending these cases in court when there is a bad outcome is extremely difficult. The key to success is choosing the right candidate.

BOFILL: The best candidates have a prolonged second stage of labor or nonreassuring fetal status with the head at the outlet or low in the pelvis and a functioning epidural.

I also would include cases with little or no rotation required. These patients account for about 50% of our operative vaginal deliveries. They are the best cases to teach and to learn.

HAYASHI: I recently reviewed a case in which the patient had been in the second stage of labor for 3 hours. The fetus was at +3 station and in the left occipital transverse position, and no progress had been made for 2 hours with epidural anesthesia. After a discussion with the attending, the physician, who was 2 years out of residency, elected to perform a cesarean.

One might argue that this was the best course, given the physician’s lack of confidence and experience performing rotational operative delivery. However, in experienced hands, flexing the fetal head and rotating the fetus to the occiput-anterior position could have resulted in an easy delivery. Unfortunately, in today’s medicolegal climate, the obstetrician may be liable if the operative delivery is difficult in any way.

Overreaction to cord compression

GARITE: One of the biggest problems with fetal heart rate monitoring is overreaction to cord compression patterns, which are rarely associated with adverse outcomes. Unless a prolonged deceleration is unremitting, I would be careful about performing operative vaginal delivery on the basis of questionable fetal heart rate monitoring.

LONKY: Still, when there is a prolonged deceleration, it sometimes is difficult to do nothing. Increased litigation has eroded our confidence. Do you agree?

VINES: The confidence factor definitely comes into play. No matter how well we can describe the physiology behind cord-compression decelerations and why they do not indicate a fetus in trouble, some physicians will be willing to testify that cord-compression-type decelerations are ominous, and will argue that the prudent doctor would have anticipated a bad outcome and changed directions earlier.

A real problem arises when, during the second stage of labor, the cord-compression issue evolves into prolonged bradycardia without remission and there is a finite amount of time to act. Frequently, an expeditiously applied vacuum is much more timesaving than a cesarean delivery.

Physicians often respond to anxiety about litigation rather than do the best thing for the fetus.

BOFILL: We do a significant number of deliveries for cord-compression patterns with the baby at the outlet. I used to be somewhat critical; now, I am a bit more pragmatic, having examined many cases. Babies and mothers did well, and cord gases were normal or nearly normal, with normal Apgar scores.

Continued...
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