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Fetal risk in delivery with the Shute parallel forceps
Fetal risk in delivery with the Shute parallel forceps Analysis
of 1,503 forceps
PROF.
SC.MED.
DR.
DR.MED. Restock,
G.
deliveries
SEIDENSCHNUR
E. KOEPCKE D. D. R. (East
Germany)
A total of 1,503 vaginal deliveries with the Shute parallel forceps duting.a 10 year period are analyzed as to the risk of instrumental damage. In this series, 35 infants died intrapartum or neonatally. Eliminating all deaths from unrelated causes, three remain in which the forceps could possibly have been implicated. Investigation of these, however, revealed in each case the presence oi other concomitant and potentially lethal factors, none of which could be completely ruled out as the primary cause of fetal death. Each of the three cases is discussed in detail. We conclude from our series that the Shute forceps is useful in the delivery of premature infants, but should be employed for this maneuver only by very experienced operators. In these cases, midforceps should be performed only for critical indications. The risk of damage with parallel forceps; deliveries from the pelvic floor is minimal if decision for operation is based on cardiotocographic criteria, and under favorable degrees of oxygenation. In the delivery of the immature infants, the parallel forceps can, in fact, hardly be superseded by any other instrument because of its uniique controlled protection of the fragile fetal head from even the pressures of the birth canai. D4ivery with the Shute forceps can be performed effectively under pudendal block or local infiltration anesthesia. (AM. J. OBSTET. GYNECOL.
135:312,
1979.)
THIS REPORT embodies the results of our clinical experience over a 10 year period from August, 1967, to March, 1977, wherein, from a total of 20,396 deliveries, 1,503 were completed by means of the Shute parallel forceps (Fig. 1). According to the listing in Table I, up to 1975, 54.1% were performed for prophylactic and 45.9% for therapeutic indications. Since that time, our approach to operative interference has been based on intrapartum criteria only, with a consequent relative increase of the therapeutic indications to 60% (228 cases) as against 35.9% (66 cases) in 1975. Of these deliveries, 74.7% were by outlet forceps and 25.3% by midforceps in accordance with the criteria of Kubli (Table II). Since 1967, the Shute forceps has been in constant use in our clinic.13 Compared with conventional scissors models, its advantages include: (1) an accurate cephalic
From
Der Frauenklinik.
Received for publication Accepted Nowember
October
13, 1978.
29, 1978.
Reprint requests: Prof. Dr. Med. G. Seidenschnur, Frauenklinik, Restock 25, Sudstadt, D.D.R. (East Germany).
312
curve based on the cqnstant ratio between the biparieta1 and bizygomatic diameters, (2) exactly parallel relationship of the blades when applied to and locked upon the head, and (3) the unequalled versatility of the instrument.3r 13-16 Based on analysis of all causes of fetal death during and following labor, we wish to comment on its specific use in the delivery of premature infants. The graph in Fig. 2 demonstrates the almost continuous rise in frequency of parallel forceps deliveries from 1969 to 1973, from 2.1 to 8.6%, leveling off during 1975 from 8.3 to 8.5%. This evolved as result of electronic monitoring of labor and strict biochemical control of the fetal conditions in our clinic. With introduction of routine determination of umbilical pH’* and close coordination between cardiotocographic findings and labor dynamics, the frequency of forceps rose to 69% in 1976 and 1977 to reduce the factor of acidosis morbidity. R~UltS When the series of instrumental deliveries is graded by fetal size (Table III), it is seen that 227 infants weighed 2,500 grams or less and 181 weighed between 2,500 and 2,800 grams-a total of 408 infants (27.1%).
000%9378/79/190312+06$00.60/0~
1979The
C.V.MosbyCo
Fetal
Fig. 1. The Simpson and the Shute parallel forceps showing relationship application and their comparative lengths of shank. Table
I. Indications
risk in delivery
with Shute
forceps
313
ofblades to head in cephalic
for use of Shute forceps Prophylactic
1. Clinical (a) Maternal disease: heart disease, gestoses, severe myopia, etc. (b) Factors in labor: prolongation, especially of the second stage due to deflection attitudes, direct occiput posterior, elderly primigravida, delay in labor of second twin with normal contractions and normal cardiotocography (c) Fetal immaturity (32 to 37 weeks) 2. Cardiotocography (a) Tachycardia, arrhythmias, frequent extrasystoles (b) Variable deceleration sisting
pattern, medium, severe, per-
3. Analysis of fetal blood gas, usually combined with abnorma1 cardiotocography (a) Preacidosis, pH 7.25 to 7.20 (b) Trend toward acidosis when pH is A pH > O.l/hr Of these, 35 children died during labor or within the first 7 days of life. Thus, of 1,276 infants of normal weight (over 2,500 grams) only 12 (0.9%) failed to survive, whereas of 227 under 2,500 grams, 23 (9.10%) died. Of the 35 deaths, seven occurred during labor, 15 within the first 24 hours, 12 by the second day, and 1 on the fifth day. Classification of fetal deaths according to the most severe pathomorphologic findings (Table IV) reveals the following causes. Causes of fetal death unrelated to instrumental trauma. These include ( 1) respiratory insufficiency with intense immaturity (11 cases) and (2) traumatic cerebral hemorrhage of the vena terminalis and subarachnoid hemorrhage in immature and mature infants resulting from the pulmonary complications of
The-apeutir
1. Clinical (a) Prolonged second state despite normal or very strong contractions with normal cardiotocography (b) Amnionitis: temperature of 38” or more with fetid amniotic fluid
2. Cardiotocography (a) Late decelerations with corresponding other danger signals (b) Bradycardia
increase in
(c) Terminal bradycardia 3. Analysis of fetal blood gas. Acidosis pHF = 7.20
amniotic fiuid emboli (four cases), including morbus hemorrhagicus neonatorum (four cases). Subdural hematoma with rupture of the tent&urn cerebelli (three cases). Fig. 3 shows graphically the continually decreasing fetal mortality rate during the 10 year period under scrutiny from the increasing use of corrective criteria in deciding the need for forceps intervention. In three children only, as mentioned above, rupture of the tentorium cerebelli suggested that instrumental trauma was the causative factor. Brief analyses of each case follow. Ceee reporb Case 1. The mother was 42 years of age. Therapeutic midforceps were used because of intrauterine hypoxia. The child (Clifford II) weighed 2,850 grams and was
314
Seidenschnur
and Koepcke
Deliveries/ Forceps(proportion) 4,518112
%
:
5
15552358]
:
fGq
:
.
.
.
.
.
.
.
.
16.
.
.
14.
.
.
.
.
IS.
12.
pig.1
. .
10.
. 8. 6. 4.
. .
2.
.
.
.
/
Fig. 2. Frequency of use of the Shute forceps-its studied (1967 to 1977). Table II. Definition the infant’s head
of the position
of
Table No.
High forceps: Application to head prior to full engagement point of head above interspines level High midforceps: Application where the head is engaged at its lowest point station 0 and +2 Low midforceps: Head at station +3 to +4. Includes all forcep rotations from Op and OT positions Outlet forceps: Head at station +4, head on perineum, and scalp visible at the outlet Table III. Forceps to weight classes
deliveries
grouped
according
d Upto1,500 Up to 2,000 Up to 2,500 Up to 2,800
8 60 159 181
rapidly increased employment during the period
3.5 26.4 70.0 -
0.5 4.0 10.6 12.0
48 cm. long. Labor lasted for 9% hours; the infant died during labor. Autopsy findings included incomplete tentorial dehiscence with subdural hematoma. Case 2. The mother was 33 years of age. Prophylactic forceps were employed from the pelvic floor. The child weighed 2,100 grams and was 43 cm. long. Labor lasted for 1 hour and 10 minutes; the infant died 1 hour and 20 minutes after delivery. Autopsy findings included rupture of the tentorium with subdural hematoma and massive amniotic fluid aspiration. Case 3. The mother was 24 years of age. Therapeutic
11 6
IV. Fetal death:
Analysis
of causes
Cause Respiratory insufficiency with a high degree of immaturity Traumatic cerebral hemorrhages from causes other than labor (vena terminalis hemorrhage, subarachnoid hemorrhage) Respiratory distress syndrome of mature infants as result of pulmonary complication, including morbus hemorrhagicus neonatalis Hydrops with morbus hemolyticus neonatorum Amnionitic syndrome with fetal sepsis Cerebral hemorrhage due to birth trauma (subdural hematoma with rupture of the tentorium) Intrapartum, from chronic placental insufficiency and obstruction of the umbilical cord Intrapartum, without morphologically determinable cause Multiple malformations of the central nervous system and eventration
midforceps were used from the occiput posterior position, in week 38 of pregnancy, for hypotrophia. The child weighed 23,400 grams and was 44 cm. long. Labor lasted for 3 hours; the infant died 29% hours post partum. Autopsy findings included traumatic subdural and subarachnoid hemorrhage with strain of the cervical spinal cord. Ten further deaths resulted from a variety of causes: hydrops with morbus hemolyticus neonatorum, amnionitis, fetal sepsis, meconium peritonitis with eventration, intrapartum death of the fetus from chronic placental insufficiency and complications in the umbilical cord. One additional child died during labor without determinable cause. This investigation is, however,
Volume
135
Number
3
Fetal
I6,552
1967 1968 1969 1970 1971
risk in delivery
with Shut@ forceps
315
. . . . . . . . . .
1972 1973 1974 1975 1976 19771t4arm
Fig. 3. Intranatal and postnatal deaths, showing rapid decrease of both with use of the Shute forceps during the period studied (1967 to 1977).
Table V. Traumatic cerebral subarachnoid hemorrhages)
hemorrhages
FL& ofpelvis
from causes other
No.
Weight (gm)
Length (cm)
1796171
2,600
47
1106171
1,970
43
2234170
2,110
44
117168
2,610
47
X
X
1194168
1,840
42
X
X
3166167
1,770
42
than labor (vena terminalis
Center
Prophyl.
ofpelvis
forceps
Died
X
X
Second day post partum
X
X
Second day post partum
X
Second day post partum First day post partum Second day post partum
X
X
Therap. forceps
Findings
First day post partum
concerned with clear differentiation between traumatic hemorrhages unrelated to delivery and those associated directly with birth trauma (Table V).
Comment One of the most relevant purposes of perinatal medicine in relation to operative delivery is the elimination of trauma to the child and increased risk to the mother. Investigation of the results of operative delivery poses searching questions as to timing, fetal development, and obstetric indications for instrumental intervention. This requires the coolest clinical judgment backed by the concurrent use of such adjunctive tests as cardiotocopgraphic findings and fetal blood gas analy-
hemorrhages,
on autupy
Subarachnoid and intrabgamentar hemorrhage in falx cerebri, respiratory insufficiency with hyaline membrane disease Vena terminalis hemorrhage with hematocephalus internus, respiratory distress syndrome with hyaline membrane disease Localized subarachnoid hemorrhages, extensive atelectasis with respiratory distress syndrome Hematocephahrs internus atelectasrs of the lungs Intraligamentous hemorrhages in falx cerebri, subarachnoid hemorrhage, immaturity. amniotic fluid embolus Massive subarachnoid hemorrhage in the cerebellopontine region, complete atelectasis of the lungs, immaturity
sis.4* 5 Hence the combination of electronic and controlled biochemical monitoring provides very valuable support mechanisms to sound obstetric .judgment in assuring the lowest possible operative risk to baby and mother. With such correlative data, rash emergent? interference should, with few necessary exceptions. become extremely rare. We regret that at present it is impossible to compare our results with those of other clinics, since our clinical and scientific approach varies considerably from that of others. HickPs * quite correctly stated that, with so many factors coincidentally operative in any one case, there are almost no clear-cut criteria to indicate the presence or extent of instrumental trauma during de-
316
Seidenschnur
and Koepcke
livery. Previously our criteria for the analysis of clinical material were based solely on postpartum pathologic anatomic findings. Only since 1974 have we had the advantage of data processing6 to summarize and add its relevant evaluation. The question of the risk of fetal damage during delivery continues to be of the utmost importance since decision for operative interference depends on expert clinical judgment. This fact must be stressed because, even in autopsy findings, intracranial hemorrhages are often incorrectly ascribed to birth trauma with far from sufficient proof for that conclusion and summarily dismissed as such. We have, therefore, submitted our material to careful analysis, emphasizing the groupings of Amiel,’ whose criteria we have found acceptable. He described several types of intracranial hemorrhage: Subependymal-from the vena terminalis with or without penetration of the ventricle, occurring mainly in preterm infants, independent of labor. In such cases, inadequate formation of the basal membrane and intercellular substance and capillaries, arterioles, and venules, with added damage to vascular walls by hypoxic acidosis and failures in coagulation, are perhaps the most relevant causes of vascular rupture with consequent circulatory failure in the region of the vena cerebralis magna, as result of damage configuration.’ Subarachnoid-from intrauterine hypoxia and prolonged labors with dystocia where immaturity of the vessel walls and failure in coagulation play a dominant role. These may occur in both mature and immature infants. According to Amiel,’ subdural hematomas only should be considered as due to birth trauma. How then, does this lesion develop? In mosi cases it occurs in mature children with difficult instrumental extraction, resulting in iatrogenic dislocation of the skull bones with a shearing separation of skull and brain surface. This leads to evulsion of veins coursing from the leptomeninx to the superior or transverse sagittal sinus or, alternatively, to hemorrhage from fissures of dura duplications (tentorium cerebelli or falx cerebri). Analysis according to the above criteria of intra- and neonatal deaths when the Shute forceps was used reveals that in three cases only did birth trauma actually occur. In case 1 (Clifford II) it is questionable whether intrauterine hypoxia from placental insufficiency with transference may not have been the major factor. In case 2, with the use of prophylactic forceps in midpelvis, during week 32 of pregnancy, after a very short labor (1 hour and 10 minutes), hasty delivery may have compressed the premature fetal skull, causing rupture of the tentorium cerebelli. At this stage, the fetal brain is peculiarly susceptible to damage from
October Am. J. Obstet.
I, 1979 (;\nr
immaturity and potential hypoxia. In both GWS, since labor had been conventionally controlled, the evidence points with some probability toward birth trauma as the primary cause of fetal death. In the third case, in which the mother was gravida 4, para 3, the labor was also very short (3 hours). The child was somewhat immature (38 weeks) and a severe deceleration pattern from compression of the umbilical cord was observed during labor. The baby was brought forth by midforceps and had subsequent Apgar ratings of 7, 8, and 9, at 1, 5, and 60 minutes, respectively, with an umbilical arterial pH of 7.23. The infant died with signs of respiratory insufficiency 29% hours postnatally and autopsy revealed extensive hyaline membrane disease. Thus, though assuming that death was caused by hemorrhage into the medulla oblongata due to forceps delivery, one cannot exclude the possibility of a purely spontaneous vascular rupture from a very short labor with direct occiput posterior position, concurrent immaturity, and hypoxia. It would appear therefore that critical analysis of our results with the Shute forceps were in accordance with the experiences of Kliick and Lamberti,s Mann, Carmichael, and Duchin,” and Hickl,8 based on the indications for, and duration of delivery of cases at risk, We would firmly stress that the delicate brain structures of immature infants are peculiarly susceptible to damage from any undue pressure upon fragile and insufficiently protected cranial bones. Hence we feel that delivery of immature infants by the Shute forceps should be carried out only by very experienced operators, using the protective measures of firm pressure on the handles below the fulcrum of the lock to maintain protective separation of the blades, as advocated by Shute. Midforceps deliveries of premature infants should be reserved for critical indications only and, if fetal asphyxia is present, such operations should be considered potentially traumatic. In the presence of these conditions episiotomy should be performed in the primigravida. The operator, however, must always avoid the common error of estimating the cephalic station as that of the caput succedaneum, rather than the fetal skull. To decrease risk from forceps operations, it is well to be prepared for immediate cesarean section if a trial forceps should fail.‘* lo The risk of damage to the fetal head with outlet forceps is minimal, if indications for intervention are guided by the criteria of tocography and fetal blood analysis. Most important are timing, the skill of the operator, and the type of instrument employed for delivery. With immature infants the parallel forceps can, obviously, hardly be superseded by another instru-
Fetal
ment, since it is specially constructed to ensure maxima1 protection of the head by firm separation of the blades through strong manual pressure on the handles below the fulcrum of the lock. The duration of delivery should be as short as possible to prevent trauma.s We
risk in delivery
with Shute
forceps
317
have found that delivery with the Shuts torceps is completely effective under pudendal block anesthesia and local infiltration of the perinellm, helice general narcosis is seldom necessary.
REFERENCES
1. Amiel, C.: Intracranial haemorrhages-trautiatism and hypoxia, in Perinatale Medizin, Stuttgart, 1973, Georg Thieme. vol. 4, pp. 270-281. 2. Eszbach, H.: Paidopathologie, Leipzig, 1961, Georg Thieme. 3. Evelbauer, K.: Zangenentbindung heute, Geburtshilfe Frauenheilkd. 28:941, 1968. 4. Heinrich, J., Seiden.. schnur, G., Hopp, H., Koepcke, E., and Riszmann, M.: Kardiotokographie, geburtsmedizinische Entscheidungen und perinatologische Ergebnisse, Zentralbl. Gynaekol. 97:257, 1975. 5. Heinrich, J.: Fetaliiberwachungszentrale im Kreiszaal, Zentralbl. Gynaekol. 98:976, 1976. 6. Heinrich, J.; Seidenschnur, G., Putzar, H., and Schulz& C.: Eine EDV-eerechte Dokumentation und statistische Auswertung geYburtsmedizinischer und perinatologischer Daten, Dtsch. Geswesen 30:993, 1976. 7. Hickl, E. J., Amiel, C., Riittgers, H., Michaelis, R., Kiser 0.. and Haupt, H.: Geftihrdung des Feten durch operative Eingriffe; PodiumsgesprPch, 5. Deutscher Kongress fur Perinatale Medizin Berlin, in Perinatale Medizin, Stuttgart, 1973, Georg Thieme, vol. 4, pp. 278-279. 8. Hick], E. J.: Indikation und Risiko von Zangen- und Vakuumextraktionen heute. Gynikologe 8:13, 1975.
9.
10. 11. 12. 13. 14. 15. 16.
Kliick, F. K., and Lamberti, C.: Die Leitung der Austreibungsperiode Indikationen zur Geburtsbeendigung, Gynakologe 8:2, 1975. Kubli, F., Ewerbeck, H, H., Hickl, J., Kltik, F. K., and Ruttgers, R.: Operative Geburtshilfe Standortbestimmung, Gynskologe 8:61, 1975. Mann, L. L., Carmichael A., and Duchin, S.: The effect of head compression on FHR, brain metabolism and function, Ob&t. Gynecol. 39:721, 1972. Saling. E.. and Wulf. K. H.: Zustandsdiarmostik beim Neu&borenen, Fortschr. Med. 89:12, 197i.’ Seidenschnur, G., Heinrich, J., Koepcke, E.. and Hopp, H.: Erfahrungen mit der Parallelzange nach Shute. Zentraibl. Gynaekol. 94:1073, 1972. Shute, W. B.: An obstetrical forceps using a new principle of parallelism. Proc. Second Int. Congr. Obstet. Gynecol. 11:645, 1958. Shute, W. B.: Eine neue Methode zur Zangenentbindung, Med. Tekh. 80:68, 1960. Shute, W. B.: Management of shoulder dystocia with the Shute parallel forceps, AM. J. OBSTET. GYNYCOL. 84:936. 1962.
of 1,503 forceps
PROF.
SC.MED.
DR.
DR.MED. Restock,
G.
deliveries
SEIDENSCHNUR
E. KOEPCKE D. D. R. (East
Germany)
A total of 1,503 vaginal deliveries with the Shute parallel forceps duting.a 10 year period are analyzed as to the risk of instrumental damage. In this series, 35 infants died intrapartum or neonatally. Eliminating all deaths from unrelated causes, three remain in which the forceps could possibly have been implicated. Investigation of these, however, revealed in each case the presence oi other concomitant and potentially lethal factors, none of which could be completely ruled out as the primary cause of fetal death. Each of the three cases is discussed in detail. We conclude from our series that the Shute forceps is useful in the delivery of premature infants, but should be employed for this maneuver only by very experienced operators. In these cases, midforceps should be performed only for critical indications. The risk of damage with parallel forceps; deliveries from the pelvic floor is minimal if decision for operation is based on cardiotocographic criteria, and under favorable degrees of oxygenation. In the delivery of the immature infants, the parallel forceps can, in fact, hardly be superseded by any other instrument because of its uniique controlled protection of the fragile fetal head from even the pressures of the birth canai. D4ivery with the Shute forceps can be performed effectively under pudendal block or local infiltration anesthesia. (AM. J. OBSTET. GYNECOL.
135:312,
1979.)
THIS REPORT embodies the results of our clinical experience over a 10 year period from August, 1967, to March, 1977, wherein, from a total of 20,396 deliveries, 1,503 were completed by means of the Shute parallel forceps (Fig. 1). According to the listing in Table I, up to 1975, 54.1% were performed for prophylactic and 45.9% for therapeutic indications. Since that time, our approach to operative interference has been based on intrapartum criteria only, with a consequent relative increase of the therapeutic indications to 60% (228 cases) as against 35.9% (66 cases) in 1975. Of these deliveries, 74.7% were by outlet forceps and 25.3% by midforceps in accordance with the criteria of Kubli (Table II). Since 1967, the Shute forceps has been in constant use in our clinic.13 Compared with conventional scissors models, its advantages include: (1) an accurate cephalic
From
Der Frauenklinik.
Received for publication Accepted Nowember
October
13, 1978.
29, 1978.
Reprint requests: Prof. Dr. Med. G. Seidenschnur, Frauenklinik, Restock 25, Sudstadt, D.D.R. (East Germany).
312
curve based on the cqnstant ratio between the biparieta1 and bizygomatic diameters, (2) exactly parallel relationship of the blades when applied to and locked upon the head, and (3) the unequalled versatility of the instrument.3r 13-16 Based on analysis of all causes of fetal death during and following labor, we wish to comment on its specific use in the delivery of premature infants. The graph in Fig. 2 demonstrates the almost continuous rise in frequency of parallel forceps deliveries from 1969 to 1973, from 2.1 to 8.6%, leveling off during 1975 from 8.3 to 8.5%. This evolved as result of electronic monitoring of labor and strict biochemical control of the fetal conditions in our clinic. With introduction of routine determination of umbilical pH’* and close coordination between cardiotocographic findings and labor dynamics, the frequency of forceps rose to 69% in 1976 and 1977 to reduce the factor of acidosis morbidity. R~UltS When the series of instrumental deliveries is graded by fetal size (Table III), it is seen that 227 infants weighed 2,500 grams or less and 181 weighed between 2,500 and 2,800 grams-a total of 408 infants (27.1%).
000%9378/79/190312+06$00.60/0~
1979The
C.V.MosbyCo
Fetal
Fig. 1. The Simpson and the Shute parallel forceps showing relationship application and their comparative lengths of shank. Table
I. Indications
risk in delivery
with Shute
forceps
313
ofblades to head in cephalic
for use of Shute forceps Prophylactic
1. Clinical (a) Maternal disease: heart disease, gestoses, severe myopia, etc. (b) Factors in labor: prolongation, especially of the second stage due to deflection attitudes, direct occiput posterior, elderly primigravida, delay in labor of second twin with normal contractions and normal cardiotocography (c) Fetal immaturity (32 to 37 weeks) 2. Cardiotocography (a) Tachycardia, arrhythmias, frequent extrasystoles (b) Variable deceleration sisting
pattern, medium, severe, per-
3. Analysis of fetal blood gas, usually combined with abnorma1 cardiotocography (a) Preacidosis, pH 7.25 to 7.20 (b) Trend toward acidosis when pH is A pH > O.l/hr Of these, 35 children died during labor or within the first 7 days of life. Thus, of 1,276 infants of normal weight (over 2,500 grams) only 12 (0.9%) failed to survive, whereas of 227 under 2,500 grams, 23 (9.10%) died. Of the 35 deaths, seven occurred during labor, 15 within the first 24 hours, 12 by the second day, and 1 on the fifth day. Classification of fetal deaths according to the most severe pathomorphologic findings (Table IV) reveals the following causes. Causes of fetal death unrelated to instrumental trauma. These include ( 1) respiratory insufficiency with intense immaturity (11 cases) and (2) traumatic cerebral hemorrhage of the vena terminalis and subarachnoid hemorrhage in immature and mature infants resulting from the pulmonary complications of
The-apeutir
1. Clinical (a) Prolonged second state despite normal or very strong contractions with normal cardiotocography (b) Amnionitis: temperature of 38” or more with fetid amniotic fluid
2. Cardiotocography (a) Late decelerations with corresponding other danger signals (b) Bradycardia
increase in
(c) Terminal bradycardia 3. Analysis of fetal blood gas. Acidosis pHF = 7.20
amniotic fiuid emboli (four cases), including morbus hemorrhagicus neonatorum (four cases). Subdural hematoma with rupture of the tent&urn cerebelli (three cases). Fig. 3 shows graphically the continually decreasing fetal mortality rate during the 10 year period under scrutiny from the increasing use of corrective criteria in deciding the need for forceps intervention. In three children only, as mentioned above, rupture of the tentorium cerebelli suggested that instrumental trauma was the causative factor. Brief analyses of each case follow. Ceee reporb Case 1. The mother was 42 years of age. Therapeutic midforceps were used because of intrauterine hypoxia. The child (Clifford II) weighed 2,850 grams and was
314
Seidenschnur
and Koepcke
Deliveries/ Forceps(proportion) 4,518112
%
:
5
15552358]
:
fGq
:
.
.
.
.
.
.
.
.
16.
.
.
14.
.
.
.
.
IS.
12.
pig.1
. .
10.
. 8. 6. 4.
. .
2.
.
.
.
/
Fig. 2. Frequency of use of the Shute forceps-its studied (1967 to 1977). Table II. Definition the infant’s head
of the position
of
Table No.
High forceps: Application to head prior to full engagement point of head above interspines level High midforceps: Application where the head is engaged at its lowest point station 0 and +2 Low midforceps: Head at station +3 to +4. Includes all forcep rotations from Op and OT positions Outlet forceps: Head at station +4, head on perineum, and scalp visible at the outlet Table III. Forceps to weight classes
deliveries
grouped
according
d Upto1,500 Up to 2,000 Up to 2,500 Up to 2,800
8 60 159 181
rapidly increased employment during the period
3.5 26.4 70.0 -
0.5 4.0 10.6 12.0
48 cm. long. Labor lasted for 9% hours; the infant died during labor. Autopsy findings included incomplete tentorial dehiscence with subdural hematoma. Case 2. The mother was 33 years of age. Prophylactic forceps were employed from the pelvic floor. The child weighed 2,100 grams and was 43 cm. long. Labor lasted for 1 hour and 10 minutes; the infant died 1 hour and 20 minutes after delivery. Autopsy findings included rupture of the tentorium with subdural hematoma and massive amniotic fluid aspiration. Case 3. The mother was 24 years of age. Therapeutic
11 6
IV. Fetal death:
Analysis
of causes
Cause Respiratory insufficiency with a high degree of immaturity Traumatic cerebral hemorrhages from causes other than labor (vena terminalis hemorrhage, subarachnoid hemorrhage) Respiratory distress syndrome of mature infants as result of pulmonary complication, including morbus hemorrhagicus neonatalis Hydrops with morbus hemolyticus neonatorum Amnionitic syndrome with fetal sepsis Cerebral hemorrhage due to birth trauma (subdural hematoma with rupture of the tentorium) Intrapartum, from chronic placental insufficiency and obstruction of the umbilical cord Intrapartum, without morphologically determinable cause Multiple malformations of the central nervous system and eventration
midforceps were used from the occiput posterior position, in week 38 of pregnancy, for hypotrophia. The child weighed 23,400 grams and was 44 cm. long. Labor lasted for 3 hours; the infant died 29% hours post partum. Autopsy findings included traumatic subdural and subarachnoid hemorrhage with strain of the cervical spinal cord. Ten further deaths resulted from a variety of causes: hydrops with morbus hemolyticus neonatorum, amnionitis, fetal sepsis, meconium peritonitis with eventration, intrapartum death of the fetus from chronic placental insufficiency and complications in the umbilical cord. One additional child died during labor without determinable cause. This investigation is, however,
Volume
135
Number
3
Fetal
I6,552
1967 1968 1969 1970 1971
risk in delivery
with Shut@ forceps
315
. . . . . . . . . .
1972 1973 1974 1975 1976 19771t4arm
Fig. 3. Intranatal and postnatal deaths, showing rapid decrease of both with use of the Shute forceps during the period studied (1967 to 1977).
Table V. Traumatic cerebral subarachnoid hemorrhages)
hemorrhages
FL& ofpelvis
from causes other
No.
Weight (gm)
Length (cm)
1796171
2,600
47
1106171
1,970
43
2234170
2,110
44
117168
2,610
47
X
X
1194168
1,840
42
X
X
3166167
1,770
42
than labor (vena terminalis
Center
Prophyl.
ofpelvis
forceps
Died
X
X
Second day post partum
X
X
Second day post partum
X
Second day post partum First day post partum Second day post partum
X
X
Therap. forceps
Findings
First day post partum
concerned with clear differentiation between traumatic hemorrhages unrelated to delivery and those associated directly with birth trauma (Table V).
Comment One of the most relevant purposes of perinatal medicine in relation to operative delivery is the elimination of trauma to the child and increased risk to the mother. Investigation of the results of operative delivery poses searching questions as to timing, fetal development, and obstetric indications for instrumental intervention. This requires the coolest clinical judgment backed by the concurrent use of such adjunctive tests as cardiotocopgraphic findings and fetal blood gas analy-
hemorrhages,
on autupy
Subarachnoid and intrabgamentar hemorrhage in falx cerebri, respiratory insufficiency with hyaline membrane disease Vena terminalis hemorrhage with hematocephalus internus, respiratory distress syndrome with hyaline membrane disease Localized subarachnoid hemorrhages, extensive atelectasis with respiratory distress syndrome Hematocephahrs internus atelectasrs of the lungs Intraligamentous hemorrhages in falx cerebri, subarachnoid hemorrhage, immaturity. amniotic fluid embolus Massive subarachnoid hemorrhage in the cerebellopontine region, complete atelectasis of the lungs, immaturity
sis.4* 5 Hence the combination of electronic and controlled biochemical monitoring provides very valuable support mechanisms to sound obstetric .judgment in assuring the lowest possible operative risk to baby and mother. With such correlative data, rash emergent? interference should, with few necessary exceptions. become extremely rare. We regret that at present it is impossible to compare our results with those of other clinics, since our clinical and scientific approach varies considerably from that of others. HickPs * quite correctly stated that, with so many factors coincidentally operative in any one case, there are almost no clear-cut criteria to indicate the presence or extent of instrumental trauma during de-
316
Seidenschnur
and Koepcke
livery. Previously our criteria for the analysis of clinical material were based solely on postpartum pathologic anatomic findings. Only since 1974 have we had the advantage of data processing6 to summarize and add its relevant evaluation. The question of the risk of fetal damage during delivery continues to be of the utmost importance since decision for operative interference depends on expert clinical judgment. This fact must be stressed because, even in autopsy findings, intracranial hemorrhages are often incorrectly ascribed to birth trauma with far from sufficient proof for that conclusion and summarily dismissed as such. We have, therefore, submitted our material to careful analysis, emphasizing the groupings of Amiel,’ whose criteria we have found acceptable. He described several types of intracranial hemorrhage: Subependymal-from the vena terminalis with or without penetration of the ventricle, occurring mainly in preterm infants, independent of labor. In such cases, inadequate formation of the basal membrane and intercellular substance and capillaries, arterioles, and venules, with added damage to vascular walls by hypoxic acidosis and failures in coagulation, are perhaps the most relevant causes of vascular rupture with consequent circulatory failure in the region of the vena cerebralis magna, as result of damage configuration.’ Subarachnoid-from intrauterine hypoxia and prolonged labors with dystocia where immaturity of the vessel walls and failure in coagulation play a dominant role. These may occur in both mature and immature infants. According to Amiel,’ subdural hematomas only should be considered as due to birth trauma. How then, does this lesion develop? In mosi cases it occurs in mature children with difficult instrumental extraction, resulting in iatrogenic dislocation of the skull bones with a shearing separation of skull and brain surface. This leads to evulsion of veins coursing from the leptomeninx to the superior or transverse sagittal sinus or, alternatively, to hemorrhage from fissures of dura duplications (tentorium cerebelli or falx cerebri). Analysis according to the above criteria of intra- and neonatal deaths when the Shute forceps was used reveals that in three cases only did birth trauma actually occur. In case 1 (Clifford II) it is questionable whether intrauterine hypoxia from placental insufficiency with transference may not have been the major factor. In case 2, with the use of prophylactic forceps in midpelvis, during week 32 of pregnancy, after a very short labor (1 hour and 10 minutes), hasty delivery may have compressed the premature fetal skull, causing rupture of the tentorium cerebelli. At this stage, the fetal brain is peculiarly susceptible to damage from
October Am. J. Obstet.
I, 1979 (;\nr
immaturity and potential hypoxia. In both GWS, since labor had been conventionally controlled, the evidence points with some probability toward birth trauma as the primary cause of fetal death. In the third case, in which the mother was gravida 4, para 3, the labor was also very short (3 hours). The child was somewhat immature (38 weeks) and a severe deceleration pattern from compression of the umbilical cord was observed during labor. The baby was brought forth by midforceps and had subsequent Apgar ratings of 7, 8, and 9, at 1, 5, and 60 minutes, respectively, with an umbilical arterial pH of 7.23. The infant died with signs of respiratory insufficiency 29% hours postnatally and autopsy revealed extensive hyaline membrane disease. Thus, though assuming that death was caused by hemorrhage into the medulla oblongata due to forceps delivery, one cannot exclude the possibility of a purely spontaneous vascular rupture from a very short labor with direct occiput posterior position, concurrent immaturity, and hypoxia. It would appear therefore that critical analysis of our results with the Shute forceps were in accordance with the experiences of Kliick and Lamberti,s Mann, Carmichael, and Duchin,” and Hickl,8 based on the indications for, and duration of delivery of cases at risk, We would firmly stress that the delicate brain structures of immature infants are peculiarly susceptible to damage from any undue pressure upon fragile and insufficiently protected cranial bones. Hence we feel that delivery of immature infants by the Shute forceps should be carried out only by very experienced operators, using the protective measures of firm pressure on the handles below the fulcrum of the lock to maintain protective separation of the blades, as advocated by Shute. Midforceps deliveries of premature infants should be reserved for critical indications only and, if fetal asphyxia is present, such operations should be considered potentially traumatic. In the presence of these conditions episiotomy should be performed in the primigravida. The operator, however, must always avoid the common error of estimating the cephalic station as that of the caput succedaneum, rather than the fetal skull. To decrease risk from forceps operations, it is well to be prepared for immediate cesarean section if a trial forceps should fail.‘* lo The risk of damage to the fetal head with outlet forceps is minimal, if indications for intervention are guided by the criteria of tocography and fetal blood analysis. Most important are timing, the skill of the operator, and the type of instrument employed for delivery. With immature infants the parallel forceps can, obviously, hardly be superseded by another instru-
Fetal
ment, since it is specially constructed to ensure maxima1 protection of the head by firm separation of the blades through strong manual pressure on the handles below the fulcrum of the lock. The duration of delivery should be as short as possible to prevent trauma.s We
risk in delivery
with Shute
forceps
317
have found that delivery with the Shuts torceps is completely effective under pudendal block anesthesia and local infiltration of the perinellm, helice general narcosis is seldom necessary.
REFERENCES
1. Amiel, C.: Intracranial haemorrhages-trautiatism and hypoxia, in Perinatale Medizin, Stuttgart, 1973, Georg Thieme. vol. 4, pp. 270-281. 2. Eszbach, H.: Paidopathologie, Leipzig, 1961, Georg Thieme. 3. Evelbauer, K.: Zangenentbindung heute, Geburtshilfe Frauenheilkd. 28:941, 1968. 4. Heinrich, J., Seiden.. schnur, G., Hopp, H., Koepcke, E., and Riszmann, M.: Kardiotokographie, geburtsmedizinische Entscheidungen und perinatologische Ergebnisse, Zentralbl. Gynaekol. 97:257, 1975. 5. Heinrich, J.: Fetaliiberwachungszentrale im Kreiszaal, Zentralbl. Gynaekol. 98:976, 1976. 6. Heinrich, J.; Seidenschnur, G., Putzar, H., and Schulz& C.: Eine EDV-eerechte Dokumentation und statistische Auswertung geYburtsmedizinischer und perinatologischer Daten, Dtsch. Geswesen 30:993, 1976. 7. Hickl, E. J., Amiel, C., Riittgers, H., Michaelis, R., Kiser 0.. and Haupt, H.: Geftihrdung des Feten durch operative Eingriffe; PodiumsgesprPch, 5. Deutscher Kongress fur Perinatale Medizin Berlin, in Perinatale Medizin, Stuttgart, 1973, Georg Thieme, vol. 4, pp. 278-279. 8. Hick], E. J.: Indikation und Risiko von Zangen- und Vakuumextraktionen heute. Gynikologe 8:13, 1975.
9.
10. 11. 12. 13. 14. 15. 16.
Kliick, F. K., and Lamberti, C.: Die Leitung der Austreibungsperiode Indikationen zur Geburtsbeendigung, Gynakologe 8:2, 1975. Kubli, F., Ewerbeck, H, H., Hickl, J., Kltik, F. K., and Ruttgers, R.: Operative Geburtshilfe Standortbestimmung, Gynskologe 8:61, 1975. Mann, L. L., Carmichael A., and Duchin, S.: The effect of head compression on FHR, brain metabolism and function, Ob&t. Gynecol. 39:721, 1972. Saling. E.. and Wulf. K. H.: Zustandsdiarmostik beim Neu&borenen, Fortschr. Med. 89:12, 197i.’ Seidenschnur, G., Heinrich, J., Koepcke, E.. and Hopp, H.: Erfahrungen mit der Parallelzange nach Shute. Zentraibl. Gynaekol. 94:1073, 1972. Shute, W. B.: An obstetrical forceps using a new principle of parallelism. Proc. Second Int. Congr. Obstet. Gynecol. 11:645, 1958. Shute, W. B.: Eine neue Methode zur Zangenentbindung, Med. Tekh. 80:68, 1960. Shute, W. B.: Management of shoulder dystocia with the Shute parallel forceps, AM. J. OBSTET. GYNYCOL. 84:936. 1962.