Commentary and Review by:

R. Daniel Braun, MD
OBGYN.net International Representative for the United States
R.Daniel.Braun@obgyn.net

Title: Evaluation of a protocol for selecting fetuses in breech presentation for vaginal delivery or cesarean section.

Ref: Am J Obstet Gynecol 1997;177:586-92

Authors: Susanne Albrechtsen, Svein Rasmussen, Hallvard Reigstad, Trond Markestad, Lorentz M. Irgens, and Knut Dalaker

Institution: University of Bergen, Bergen, Norway


Study Design: Clinical Follow-up Study

Rating:

Abstract:

Objective: Our purpose was to evaluate, with respect to obstetric intervention and neonatal outcome, a protocol for selecting fetuses in breech presentation for vaginal delivery or cesarean section.

Study Design: A clinical follow-up study was performed between 1984 and 1992 of all term singleton deliveries in breech presentation. Each case selected for vaginal delivery had a matched control in vertex presentation.

Results: A total of 1212 infants presented as breech. Vaginal delivery increased from 45% to 57% (p = 0.004) and cesarean section for failure of vaginal delivery declined from 21% to 6% (p < 0.00001). None, however, died or had long-term sequelae because of a complicated or failed vaginal breech delivery. A total of 8.8% of those delivered vaginally in breech versus 5.0% of those in vertex presentation were admitted to the neonatal intensive care unit (p = 0.009). Among those with vaginal delivery, 2.5% in breech presentation were given the clinical diagnosis of birth asphyxia versus none in the vertex position (p = 0.0001).

Conclusion: Breech presentation at term may be selected for vaginal delivery if properly managed.

Commentary

I was real excited when I saw this article listed in the table of contents and went to it before any other article in this journal. After I read it, I was disappointed. The protocol presented here is different in content but not in theory from the Zatuchni-Andros Scoring system proposed by authors in this country . The stated objective of the study was to evaluate the protocol. The conclusion was: "Vaginal delivery is safe for the majority of the infants presenting as breech if appropriate protocols for management and adequate skills and equipment for immediate cesarean section and neonatal resuscitation are available.

The protocol used here requires X-Ray pelvimetry and estimation of fetal weight. According to the protocol the ABSOLUTE (emphasis mine) Indications for "Elective" (Elective means scheduled) cesarean section in breech presentation are as follows.

  1. Sum of outlet < 32.5 cm. (Sagittal outlet + Intertuberous +Interspinous diameters)
  2. Conjugate vera < 11.5 cm.
  3. Estimated Birth weigh < 2500 gm.

Relative indications for cesarean section were:

  1. Pathologic pelvic form because of pelvic disease or previous fracture.
  2. Footling presentation
  3. Estimated birth weight > 4500 gm
  4. Primiparous woman > 35 Y/O
  5. Previous stillbirth
  6. Premature rupture of membranes
  7. Postmaturity

The number that the authors use to determine that the outlet is too small is an interesting number.
They call this the "Sum of the Outlet", but define it as the Sagittal outlet + Intertuberous + Interspinous. I was not aware of this measurement before reading this paper. So I visited the reference that was given. This is a very interesting paper on radiographic pelvimetry. It compares several techniques of pelvimetry and shows that the different techniques have different significant values for considering a pelvis to adequate. They go at great lengths to show that the "Sum of the Outlet" of 32.5 cm., by their technique is the same as 34 cm. by the Chassard-Lapine technique. In short, if you don't use the exact same radiographic pelvimetry technique that was used by the authors, you need to come up with the same value utilizing your technique. For instance if you use the Colcher-Sussman or the Snow technique, you will need to find out what measurements will equal the 32.5 cm by the "Orthodiagraphic technique used in this paper.

No comments were made as to how the relative indications for cesarean section were used i.e.: did it require 2 of the relative indications? Were some of them weighted heavier than others? Were they applied equally by all obstetricians over the 9 years of the study?

The authors tell us there were 1230 singleton term breech deliveries in their institution and all but 18 were subjected to the protocol, leaving 1212 in the study. Of those 401 were selected for "elective" cesarean section and 811 were selected for vaginal delivery. Of those selected for Vaginal delivery, 172 (21.2%) delivered by cesarean and 639 (78.8%) delivered vaginally. For each case selected to deliver vaginally, there was a matched control vertex that delivered by the same route as the breech baby did i.e. either vaginally or intrapartum cesarean.

So there were 5 groups available for comparison; vaginal breech, vaginal vertex, intrapartum cesarean breech, intrapartum cesarean vertex, and elective cesarean breech.

Outcome Vag. Breech Vag. Vtx. IP C/S Breech IP C/S Vtx. Elect. C/S Breech
Neonatal Death 1 0 0 0 0
1 Min.Apgar<7 11% 1.8% 2.5% 12% 1%
    p<0.00001   p=0.001 p<0.00001
NICU Adm. 8.8% 5% 1.9% 17.1% 5.7%
    p=0.009   p<0.00001 p=0.3
Uneventful course 78% 88% 92% 80% 85%
    p<0.000001   p=0.001  
Hip Dislocation 10.8% 2.2% 4.4% 0.6% 9.1%
    p<0.000001   p=0.07(NS) p=0.8 comp to 1+3
Traumatic morbidity 3.3% 1.2% 1.9% 0.6% 0.3%
    p=0.01   p=0.6 p=0.002
Soft tissue trauma 2.7% 1.0% 1.9% 0 0
Fracture 0.5% 0 0 0 0
Brachial nerve paralysis 0 0.2% (1) 0 0 0.3% (1)
Birth Asphyxia 2.5% 0 0.6% 4.4% 0
    p=0.0009   p=0.03 p=0.004

The p values in column 2 are comparing column 1 to column 2. Those in column 4 are comparing column 3 to column 4. Those in column 5 are comparing column 5 to column 1 + column 3.

The above is my synopsis of the authors tables III & IV. It shows Vaginal vertex deliveries do better than Vaginal breech deliveries. Very interestingly it shows that intrapartum cesarean deliveries of a breech do better than intrapartum cesarean deliveries of a vertex. It also shows that the elective cesarean breech group had a lower incidence of one minute apgars below 7, traumatic morbidity, and incidence of birth asphyxia than did those who were selected for vaginal delivery.

My interpretation of their data is that being selected to deliver by the abdominal route is the best thing that can happen to the baby. This is because it will have a lower incidence of low one minute apgar scores (big deal !!), traumatic morbidity (This is important), and birth asphyxia(Again a truly important thing). The real question which has not been answered by these or other authors is: Is this decrease in fetal complications enough to offset the associated increase in maternal morbidity and mortality from cesarean delivery?

I think the conclusion of the study should have been: Utilizing the authors protocol, selected vaginal delivery of the breech presenting infant is acceptable if you are willing to accept a 2.5% incidence of
birth asphyxia and a 3.3% incidence of traumatic morbidity.

I think the study design is as good as can be done short of a randomized controlled trial. The use of vertex controls is interesting although, I am not sure what the comparisons really mean.

The authors feel that the high incidence of vaginal breech delivery in their institution might be attributed to the influence of Jxrgen Lxvset, the first Chairman of the Department at the University of Bergen. He described Lxvset's maneuver for delivery of the shoulders of the breech. The interested reader is referred to Baskett's "On the shoulders of Giants" .

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