4/4/05njm

Q. What are some of the issues involved with vacuum assisted deliveries?

A. The mechanics are one issue, larger issues are when to use and when
not.

As skills with operative vaginal deliver have waned, some providers have
found themselves needing to provide this service, but with small numbers
for experience. I recommend that if someone wants to add this skill in
their armamentarium that they pursue a mini-residency with skilled
providers. Please be warned this can be a very litigious area of
practice.

After one has obtained the requisite skills, then one should maintain
the skills with frequent use of the procedures. In addition, one should
consider regular attendance at Advanced Life Support in Obstetrics
Courses to review the indications and mechanics. If you have the
opportunity to take the AAFP \"ALSO\" course, it is an excellent
hands-on learning experience with workstations, and a \"mega-delivery\",
involving when and how to continue to use the vacuum.

<http://www.aafp.org/also.xml>

The mechanics are just one issue. The larger issue involves the clinical
judgment about when and when not to use these skills. This issue raises
many questions, e.g., at what station does the fetal head need to be? To
briefly answer 2 specific questions, the instrument should only be
applied if the head is at +2 station, and preferably only with the head
on the perineum (+3). It should not be used prior to 34-36 weeks because
of the risk of intracranial hemorrhage.        

See more information, below.

In addition to the brief pearls below, one should know when to abandon
the procedure. One common rule of thumb is to abandon the vacuum
procedure after 3 pop offs or 3 successful pulls. In addition, the
provider should not attempt successive attempts with the forceps and
then the vacuum, and visa versa. See material attached.

**Benchmark materials are available**

I have attached excerpts of some benchmark materials below. The American
College of Obstetricians and Gynecologists (ACOG) maintains a body of
recommendations and policies that could be helpful.

**How can I get those great ACOG materials when I am not a member of
ACOG?**

ACOG has a special classification, Educational Affiliate Non-Physician,
for any individual with an advanced degree who through professional
training and/or experience in women\'s health care is able to further
the missions of the College.

Online Educational Affiliate Non-Physician Application

<https://www.acog.com/from_home/eanondocapp.pdf>

Here are the requirements https://www.acog.com/from_home/educatreq.cfm
or

contact Bernice Rose <brose@acog.org> (202) 863-2408 Fax: 202/479/0054

Information on other types of ACOG memberships

<https://www.acog.com/from_home/departments/dept_notice.cfm?recno=22&bulletin=2635>

**For this particular FAQ let us explore some of the indications and
contraindications first.**

-   Shortening of the second stage for maternal benefit.

**What are contraindications to operative vaginal delivery*?***

Under certain circumstances, operative vaginal delivery should be
avoided or, at the least, carefully considered in terms of relative
maternal and fetal risk. Most authorities consider vacuum extraction
inappropriate in pregnancies before 34 weeks of gestation because of the
risk of fetal intraventricular hemorrhage. Operative delivery also is
contraindicated if a live fetus is known to have a bone demineralization
condition (eg, osteogenesis imperfecta), a bleeding disorder (eg,
alloimmune thrombocytopenia, hemophilia, or von Willebrand\'s disease)
is present, the fetal head is unengaged, or the position of the fetal
head is unknown.

Operative vaginal delivery should be performed only by individuals with
privileges for such procedures and in settings in which personnel are
readily available to perform a cesarean delivery in the event the
operative vaginal delivery is unsuccessful. One study showed that in
cases in which the vacuum extractor was used to deliver fetuses with
nonreassuring fetal heart rate patterns, blood gas parameters did not
differ from those in cases with normal spontaneous deliveries. The
authors concluded that the use of vacuum extraction is not
contraindicated in cases of nonreassuring fetal heart rate patterns.

Operative Vaginal Delivery\", ACOG Practice Bulletin #17, June 2000

**[Other Mechanics]{.underline}**

The vacuum cup is placed on the fetal occiput with the center of the cup
approximately 2 cm anterior to the posterior fontanelle (median flexing
point) to promote head flexion and assist with the cardinal movements of
fetal descent. It should not cover the anterior fontanelle or include
any maternal tissue.

The maximum vacuum pressure applied should not exceed 0.8 kg/cm2 of
atmospheric pressure (ie, 600 mmHg, 23.6 inches of Hg, 11.6 lb/in2).
Increasing the pressure beyond this level increases fetal risk of injury
without significantly aiding extraction. The pressure may be raised
quickly or slowly, lowered or maintained between contractions. Raising
the pressure quickly and maintaining it probably minimizes the duration
of vacuum application without increasing the risk of complications.

There are minimal data available from studies examining the optimal
technique for vacuum extraction. In general, suction should not be
applied for more than 20 minutes and the duration of application should
be documented in the chart. If the cup detaches, reapplication should
probably be limited to two attempts so that the maximum total number of
attempts at vaccum extraction is no more three. One prospective
observational study found that cosmetic scalp trauma was more common
after longer duration of vacuum application (especially over 10
minutes), longer second stage, and paramedian cup placement. However,
only nine of 130 patients in this series had a vacuum application longer
than 10 minutes.

**Traction** --- With both forceps and vacuum, steady (not rocking)
traction in the line of the birth canal should be exerted with each
contraction and in conjunction with maternal expulsive efforts. A vacuum
device is more likely to detach if angular traction is applied. In most
cases, progress is noted with the first or second pull and delivery
occurs by the third or fourth pull. The procedure should be abandoned if
descent does not occur with appropriate application and traction.

**MULTIPLE TRIALS OF INSTRUMENTAL DELIVERY** --- The American College of
Obstetricians and Gynecologists has suggested that multiple attempts at
operative vaginal delivery using different instruments (vacuum,
different types of forceps) be avoided due to the greater potential for
maternal and/or fetal injury. Evidence is mixed regarding the role and
risks of sequential applications of vacuum and forceps. In one large
study, the incidence of subdural or cerebral hemorrhage in infants
delivered by vacuum and forceps, vacuum alone, or forceps alone was
approximately 21, 10, and 8, per 10,000 births, respectively.

These findings were corroborated by another analysis based upon
state-wide birth certificate data and a study on asymptomatic term
infants who underwent routine magnetic resonance imaging within 48 hours
of birth. Nine of 111 asymptomatic infants had subdural hematomas with
the highest proportion in the group exposed to failed vacuum followed by
successful forceps delivery (five subdural hematomas among 18 infants).
In addition, three subdural hematomas occurred in 49 infants
spontaneously delivered from vertex presentation and one subdural
hemorrhage occurred after a failed vacuum delivery. No subdurals were
noted in the remaining infants (25 infants delivered by cesarean, four
delivered by forceps, 13 delivered by vacuum, and one delivered by
cesarean after failed forceps). All hematomas had resolved without
clinical sequelae when reevaluated four weeks later.

However, two other small studies did not show adverse effects from
sequential use of vacuum and forceps, even when vaginal delivery was not
achieved.

For more on this topic from UpToDate

**UpToDate: Operative Vaginal Delivery**

<http://www.uptodateonline.com/application/topic.asp?file=labordel/7855&type=A&selectedTitle=1~10>

**Operative Vaginal Delivery**

ACOG Practice Bulletin #17, June 2000

**Summary**

***The following recommendations are based on good and consistent
scientific evidence (Level A):***

-   Both forceps and vacuum extractors are acceptable and safe
    instruments for operative vaginal delivery. Operator experience
    should determine which instrument should be used in a particular
    situation.

-   The vacuum extractor is associated with an increased incidence of
    neonatal cephalohematomata, retinal hemorrhages, and jaundice when
    compared with forceps delivery.

***The following recommendations are based on limited or inconsistent
scientific evidence (Level B):***

-   Operators should attempt to minimize the duration of vacuum
    application, because cephalohematoma is more likely to occur as the
    interval increases.

-   Midforceps operations should be considered an appropriate procedure
    to teach and to use under the correct circumstances by an adequately
    trained individual.

-   The incidence of intracranial hemorrhage is highest among infants
    delivered by cesarean following a failed vacuum or forceps delivery.
    The combination of vacuum and forceps has a similar incidence of
    intracranial hemorrhage. Therefore, an operative vaginal delivery
    should not be attempted when the probability of success is very low.

***The following recommendations are based primarily on consensus and
expert opinion (Level C):***

-   Operative vaginal delivery is not contraindicated in cases of
    suspected macrosomia or prolonged labor; however, caution should be
    used because the risk of shoulder dystocia increases with these
    conditions.

-   Neonatal care providers should be made aware of the mode of delivery
    in order to observe for potential complications associated with
    operative vaginal delivery

**Operative Vaginal Delivery** ACOG Practice Bulletin #17, June 2000

ACOG members

<http://www.acog.org/publications/educational_bulletins/pb017.cfm>

Non- ACOG members

See above approach to obtain ACOG materials

**Other issues to explore**

Clinical Pelvimetry: assessment of the maternal pelvis before performing
midpelvic delivery.

**Criteria for Operative Vaginal Delivery**

Not included in classification.

**Another resource**

OBG Management: There is a very good review in the Feb 2004 issue.