Clinician to Clinician: Bringing operative vaginal delivery into the 21st century

Dr. Perone is a clinical professor in the Department of Obstetrics, Gynecology & Reproductive Sciences at the University of Texas Medical School at Houston. He reports holding a patent for an electronically controlled axis-traction handle and 2 related patents.

Operative vaginal delivery (OVD) still plays a valuable role in obstetrics, despite its continuing decline. Many factors account for such a decline, including, in particular, doctors’ fear of litigation and reduced competency. Modern technology may preserve the use of forceps and vacuum extractor before it becomes a lost art.

The rate of OVDs has been declining in most countries since the mid-1970s. In the United States, it has gone from 28% in 1970 to 9.01% in 1990, with a further drop to 3.5% in 2011.¹ The rate of forceps use has dropped from almost 30% in the late 1960s to less than 1% in 2005, where it has remained. Vacuum extraction (VE) was seldom used in the United States until the early 1980s, but subsequently became the most common method of OVD after a marked increase from 3.5% in 1989 to 6.2% in 1997. Since then the rate of VE has steadily declined to a low of 2.85% in 2011.²

Reasons behind OVD loss of favor

A number of factors account for the decline in the rate of OVD, however medico-legal concerns may play a major role. In the 2012 ACOG professional liability survey, 77.3% of respondents said that they had been sued at least once, with an average of 2.64 claims per ob/gyn.³ Plaintiff attorneys frequently blame forceps and VE for bad obstetrical outcomes, although it is widely believed that the indication for their use is probably a more important causative factor than the delivery itself.⁴ This is particularly so in the case of neonatal neurologic damage, similar to what has been observed in case of cesarean delivery,⁵ which, despite its increasing rate, has not caused a reduction in cerebral palsy. In fact, a recent systematic literature review and meta-analysis has shown an increased risk of this neurologic condition in association with emergency cesarean delivery, confirming the important causative role of antepartum risk factors.⁶

The reduced use of OVD and increased use of cesarean delivery at many teaching institutions has reduced resident competency in OVD. This may set in motion a vicious cycle, wherein lack of expertise causes errors when using forceps or VE, leading to more lawsuits, which in turn further discourages OVD. The important questions facing our specialty today are whether we want to passively witness OVD become “a lost art”⁷ while the cesarean delivery rate continues to climb, or whether we should actively attempt to reverse the current trend and, if so, how.

Why proficiency in OVD should be maintained

OVD should not be allowed to become extinct. Proficiency in the use of forceps and VE should be maintained for the following reasons:

 Cesarean delivery is not a panacea for all obstetrical emergencies. In fact, OVD can save the day whenever a cesarean delivery is either relatively contraindicated by maternal conditions or, as it happens more often, preparation for it cannot be made in a timely fashion (only 65% of emergency primary cesarean deliveries are done within 30 minutes of the decision to operate).⁸

 Given current patient safety and health care cost concerns, the potential moderating impact of OVD is widely acknowledged.^9-11 In my opinion, it is no accident that, while OVD rates have gradually decreased, the rate of cesarean delivery has increased by more than 50% since 1996, going from 21% to 32.8 % in 2011. And this upward trajectory appears likely to continue, with estimates of an overall cesarean rate of 56.2% by 2020, if the primary and secondary cesarean rates continue at the same pace as in recent years.^12,13 Of course, it is difficult, if not impossible, to quantitate precisely the effect that more frequent use of OVD would have on these rates. But it is clear that even a small reduction in cesarean deliveries could have considerable economic benefits. In fact, for every 5% increase in the US cesarean delivery rate one can expect $750 million to $1.7 billion in additional healthcare costs.¹⁴

Preserving the use of forceps and VE with modern technology

It is my belief that OVD could be revived with the help of modern technology. Since their introduction in the 17th century, forceps have undergone only few changes. Fifty years ago A.R. Fleming lamented that they remained “little more than a shoehorn,” an obvious paradox in our era of cutting-edge technology.¹⁵

Updated technology that made OVD simpler and safer would make obstetricians less reluctant to use this modality. As for the doctors’ legal vulnerability, the considerable advances in electronic engineering would reduce it in 2 ways: by improving the instruments’ safety and by making it easier for obstetricians to defend themselves in cases of bad outcome associated with, but not caused by, OVD.

With regard to the safety of the instruments, a known limitation of the traditional instruments is that traction is measurable only by subjective feel. Consequently, there is always the possibility of fetal injury secondary to inadvertent use of excessive traction. In fact, this is a likely occurrence, particularly when employed by inexperienced practitioners in the presence of unrecognized cephalo-pelvic disproportion which can be difficult to predict prospectively. Enhanced technology would help solve the problem of the inadvertent application of excessive traction by making the instruments capable of measuring the pull applied and by alerting the obstetrician when traction exceeds preset safety limits.

Currently, avoidance of excessive traction and, more importantly, when to abandon an OVD attempt and promptly resort to a cesarean delivery is left to the obstetrician’s judgment, acquired after years of experience. Yet, we know from clinical and experimental data that, in the case of forceps, a traction force of 50 lb (22.8 kg) should be considered the upper limit of pull with regard to fetal safety^16,17 and in the case of VE, that the traction should be limited to the negative pressure under the cup (generally recommended not to exceed 550–600 mmHg), otherwise detachments are inevitable and with them the possibility of fetal injury. The occurrence of serious fetal scalp lacerations and life-threatening hemorrhagic complications associated mainly with vacuum cup “pop-offs” prompted a 1998 FDA Public Health Advisory.¹⁸

By giving forceps and VE the capability of measuring the pull applied and of alerting the doctor when “gentle” traction becomes undue traction, we could bring “a modicum of scientific objectivity into a sphere replete with subjectivity,” to borrow from JV Kelly.¹⁹ This, in turn, would make the correct use of these instruments less experience-dependent and thus reduce the risk of fetal injury, even in the hands of a novice. In fact, if the pull reaches the upper limit of safety and there is no evidence of progress, the need to desist from further extractive efforts and to abandon the vaginal route in favor of the abdominal one would be obvious.

The availability of unassailable documentation would make it easier to counter the medico-legal allegations of undue force in cases associated with adverse obstetrical outcomes. In fact, in the absence of objective data, as is the case with the instruments currently used, the doctor’s recollection of the traction applied is invariably, and often successfully, challenged.

Technology would remedy loss of competency by helping remove barriers that often impede effective teaching of OVD techniques. The answer here lies in the greater use of simulators, ideally of the high-fidelity kind with haptic feedback capability, which require fewer instructors and less time. Simulators not only teach OVD, but also help doctors to maintain and sharpen their skills. In fact, periodic simulator-based training could be made mandatory in order to maintain OVD privileges. The use of simulators, coupled with the designation of a full-time experienced and proactive faculty member to this task, has led to a reported 59% increase in forceps use,²⁰ which is particularly significant when taking into account that this instrument is technically more demanding than VE.

Engineering feasibility

Some may consider the improvements suggested to modernize forceps and VE too challenging to become a reality. However, their feasibility has already been demonstrated.²¹ In fact, thanks to miniaturized electronics, these instruments can be used without learning new skills and unencumbered by dials, scales, and cables.

References

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15. Fleming A R. Discussion in: Pearse W. Electronic recording of forceps delivery. Am J Obstet Gynecol. 1963;86:43–51.

16. Pearse W. Electronic recording of forceps delivery. Am J Obstet Gynecol. 1963;86:43–51.

17. Kelly JV, Sines G. An assessment of the compression and traction forces of obstetrical forceps. Am J Obstet Gynecol. 1966;96:521–537.

18. Food and Drug Administration. FDA Public Health Advisory: need for caution when using vacuum assisted delivery devices. Rockville, Md: Center for Devices and Radiological Health. US Dept of Health and Human Services, May 21, 1998.

19. Kelly JV. Compression of fetal brain. Am J Obstet Gynecol. 1963;85:687–694.

20. Solt I, Jackson S, Moore T, Rotmensch S, Kim MJ. Teaching forceps: the impact of proactive faculty. Am J Obstet Gynecol. 2011;204:448.e1–4.

21. Perone N. The electronically controlled axis-traction handle. Preliminary report. J Obstet Gynaecol Res. 2010;36(5):1080–1086.