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Presentation and prolapse of the umbilical cord
PRESENTATION AND PROLAPSE OF THE UMBILICAL CORD L. M.
NoRBURN,
M.B., CH.B., M.R.C.O.G.,
NORTHAMPTON, ENGLAND
(From St. Mary's Hospitals, Manchester, England)
( ) VER 100 years ago James Stephens 1 wrote, "The fatal results, as regards '--"" the life of the child, so frequently observed when the cord descends during labor, renders it very desirable to endeavour to lessen the excessiYe mortality shown in the records of the profession." These words would still appear to he true today, when the fetal mortalit,\' is authoritatively quoted as varying from 50 to 60 per cent. 5 It is the purpose of this papet· to investigate those cases in which prolapse of the fetal umbilical cord occurred and to attempt to learn how the related fetal perinatal mortality may be further reduced. The material for this paper has heen obtained from a study of all the cases of prolapse or presentation of the cord occurring in Saint Mary's Hospitals during the 5 year period, 1951 to 1955. This quinquennium is later compared with the corresponding period 20 years earlier.
Incidence Presentation or prolapse of the cord occurred 84 thnes in 16,487 consecutive deliveries from 1951 to 19fl5 at St. Mary's Hospitals, a total incidence of 0.51 per cent or 1 in 196. The incidence in "booked" cases was 0.43 per cent or 1 in 232, while in "emergency" cases it was 1.12 per cent or 1 in 89. The emergency cases accounted for 24 per cent of the total admissions. A total of 1,031 fetal perinatal deaths occurred during this period and of these, 2.9 per cent or 1 in 34 were related to pr('Sentation or prolapse of tht' cord. Table I shows the incidence of prolapse of the cord in relation to maternal ago and parity. I.1et us exclude for the moment the very young nulliparous gToup where the high incidence of prolapse of the cord is related to the high frequency of prematurity ( 60 per cent). It is now seen that the risk of corr1 prolapse increases as either maternal age or parity increases. IT owever, the greatest risk of cord prolapse at each parity changes from the oldest age group in the nulliparous patients to the youngest age group in the grand multiparous patients. This very high risk (1 in 21) in the youngest age group of tht> grand multiparas demonstrates one of the various disadvantages associatf;d with the too frequent recurrence of pregnancy.
Etiological Factors The incidence of the various etiological factors for the 5 year period is shown in Table II. The factors, of course, may be multiple in any one ease. 1234
1235
PRESJ;;NTA'l'ION AND PROLAPSE OF UMBILICAL CORD
\ olume 78 :\'umber 6
'l'ABLE I.
INCIDENCE OF PROLAPSE OF THE CORD IN RELATION TO AGE AND PARITY
Para 0
UNDER 20 5 in 414 (I in 83)
20-24 6 in 2074 (1 in 346)
25-29 4 in 1865 (1 in 466)
Para i
0 in 46
3 in 512 (1 in 171)
4 in 914 (1 in 228)
Para ii
0 in
4
1 in 117 (1 in 117)
Para iii
0 in
1
0 in
23
Para iv
0 in
0
0 in
1
Para v and over Total
Oin
0
0 in
4
5 in 465 in 93)
(1
10 in 2731 (1 in 273)
AGE (YEARS) 30-34 5 in 1024 (lin 205)
35-39 2 in 555 (1 in 277)
OVER 40 1 in 195 (1 in 195)
TOTAL 23 in 6127 (1 in 266)
4in 751 (1 in 188)
5in 479 (1 in 96)
4 in 166 (1 in 41)
20 in 2868 (1 in 143)
3 in 398 (1 in 133)
4in 401 (1 in 100)
(1 in
5 in 291 58)
1 in 104 (1 in 104)
14 in 1315
1 in 132
(1 in 132)
6 in 200 (1 in 33)
3 in 140 (1 in 47)
0 in 77
lOin 573 57) (lin
1 in (1 in
56 56)
2 in (1 in
93 46)
1 in 105 (1 in lOti)
0 in 43
4in 298 (1 in 74)
Oin
39
6 in 128 (1 in 21) 27 in 2597 96) (1 in
4 in 16fl ( 1 in 42) 20 in 17:i!l (1 in R71
3 in 130 (1 in 43) 9in715 ( 1 in 79)
13 in 440 ( 1 in 34)
] :lin :l404 (1 in :Zti2)
I
I
(1 in
Malpresentation was by far the commonest single predisposing faet01·. Prolapse of the cord occurred only once in ever·y 379 eases of vertex presentation, but when the fetal presenting part fitted the lower segment of the uterus less accurately, the incidence rose markedly to 1 in 59 with face presentation. 1 in 30 with breech presentation, and 1 in 6 with transverse lie or compound presentation. It is interesting to see how infrequently prolapse of the cord is predisposed to by pelvic contraction or placenta previa, but, as will be seen later, their importance in relation to fetal perinatal mortality far outweighs their etiological frequency. TABI,E II.
TNCIDENCE OF' ETIOWG!CAL FACTOltS
ETIOLOGICAL Jo'ACTORS
--~-Malpresentation
<
----~-
Prematurity ( 51;2 pound~) Multiple pregnancy Grand multipara (Para v+) Ri!lh mobile head when membranes ruptured Hvdramnios ~ Piacenta previa Fetal abnormality Contracted pelvis Obstetrical manipulations Obliquity of uterus Vomiting under anesthesia Unknown
NO.
INCI-DENCE ( o/o)
32
38.1 23.fi J 5.5 15.5 9.5 1'!.3 8.3 7.1 5.9 1.1 1.1 5,9
---:vf ___'-----;o5c;-1.-;;2--'----'--HI
13 13 8 7 i H
5
1
1
5
Five eases of prolapse of the eord oecurred dm·ing the course of obstetrical manipulations. T,vo of these oecurred during vaginal n1anipulations at the time of attempted forceps delivery (one of them before admission to hospital) ; one followed artificial rupture of the forewaters in the presence of a high and mobile head; another occurred when labor was induced with a hydrostatic bag which displaced the presenting part and allowed the cord to prolapse; and the other was a case of transverse lie with ruptured forewaters whirh was treated by internal version followed by plugging the cervix with the half breech, but it was discovered later that this trapped the cord between the cervix and breech. Diagnosis Prolapse of the cord was diagnosed on 84 occasions, and on 28 of these (:3:3.0 per cent) the diagnosis was made only when the cord presenterl at the
94)
1236
NORBURN
\m_ .L ObsL & Gynec. December, 1959
vulva. After excluding the 6 cases in which the child was delivered almost immediately after discovery of the cord at the vulva, the corrected perinatal mortality was 23.5 per cent. This compares satisfactorily with the eonectcd perinatal mortality of 25 per cent for all cases. It is therefore doubtful if spasm of the cord vessels plays such an important role in causing fetal death as has been suggested• since presumahly the vascular spasm would he most marked in those cords which prolapse outside the vulva. In the remaining cases, the prolapsed cord was found on digital pelvic examination, but in only 12 cases (1±.3 per cent) was the vaginal examination performed for fetal distress. Most comn1onl.Y (4'7.6 per cent of all cases) the prolapsed cord was found during routine vaginal examination with the possibility in mind; following spontaneous rupture of the membranes (20 cases); while the course of labor was being assessed (14 cases); or following delivery of the first of twins (6 cases). In 4 cnses (4.8 per cent) the prolapsed cord was found during vaginal manipulations.
Prognosis
A. Maternal Mortality.-There were no maternal deaths associated with prolapse of the cord during the period under review. B. Fetal Perinatal Mortality.-There were 30 fetal perinatal deaths due to prolapse of the cord from 1951 to 1955, giving a perinatal mortality rate of 1.9 per 1,000 deliveries. The value of antenatal care even in this obstetrical emergency is seen when the fetal perinatal mortality for booked cases is found to be 32.3 per cent 'l:hile that for the emergency cases is 47.4 per cent. Examination of Table III will show how the corrected fetal perinatal mortality of 25 per cent has been obtained frorn a gross perinatal n1ortalit..v of 35.7 per cent. It will be noted that the correction has been made only in order to obtain the perinatal mortality for "treatable" cases. The treatable cases arc those cases i11 "\vhich the fetus is alive and nor1nal \vhen the patient is admitted to hospital. No correction has bern made for prematurity, except in so far as all the cases were at or paRt the twenty-righth week of gestation. TABLE
III.
CORRECTED FETAI, PERINATAL MORTALI'l'Y
I ____ NO.
Total cases of prolapse of cord Number of perinatal deaths Less fetal abnormalities incompatible with life 7 Less babies dead on admission but otherwise normal 5 Remaining perinatal deaths Total babies normal and alive on admission
FETAL MORTALITY
__ I _ ---~% I ___ >
84
:-w
18
~5.0
72
In the following analysis only treatable cases have been considered. Presentation of the cord was found on 10 occasions. This precursor of the prolapsed cord caused 2 fetal deaths before the membranes ruptured. Three of the 8 remaining patients were rapidly and easily delivered vaginally after rupture of the forewaters, while 5 were delivered by cesarean section. It will therefore be seen that at Saint Mary's Hospitals presentation of the cord is considered to be almost as serious for the fetus as true prolapse of the cord and is certainly not regarded so complacently as it is in most textbooks.
PRESENTATTOK AKD PROLAPkE OF FJ:rBILICAL CORD
Volume iR
~nmher 6
1237
Important Factors in Relation to Fetal Perinatal Mortality.1. Degree of cervical dilatation: This is a Yery important factor in relation to the fetal perinatal mortalit~-, as can be seen from Table IV. TABLE
IV.
DEGREE OF CERVICAl, DILATATION FETAL MORTALITY
CASES DILATATION OF CERVIX WHEN PROLAPSE DIAGNOSED
INC'!DEKCE
xo.
Fully dilated '!14 dilaterl lf2 dilated %dilated
I
40
55.6
-i
5.6 1 ~.ii
0
19
INCIDENCE
NO.
(%)
(%) 17.5 50.0 66.7
6
15.8
3
%.4
When the cervix is fully dilated, the fetus can usually be rapidly, easily, and safely delivered vaginally, but, with an incompletely dilated cervix, immediate vaginal delivery is appreciably more difficult; there is a much greater risk of fetal death, and replacement of the cord also carries a high fetal mortality. The perinatal mortality, therefore, falls sharply as the cervical dilatation increases. When the cervix was only slightly dilated, however, the perinatal mortality was markedly diminished, and the fetal survival rate was better than with the fully dilated cervix. This was due to the frequent use of abdominal delivery in this type of ease. It is noteworthy that all the l6 living children obtained from those cases where the cervix was only slightly dilated were delivered by cesarean section. 2 ..fi'etal maturity: Table V reveals the importance of fetal maturity in relation to the perinatal mortality from prolapse of the cord. The premature baby, as always, is adversely affected by any complication of labor. 'l'ABLE
V.
FETAL MATt'RlTY ~ 1 ~'1'..:'\.L
Mature normal babies PrPmature normal babies (
< 5~t&
pounds)
CASBS
::<10.
41
10
~5
K
rv£0RT.l1.. LITY
lNC!IlEKCe (
o/o)
~u :1~.0
3. Fetal presentation: It is surprising to find on referring to Table VI that the perinatal mortality was not appreciably influenced by the fetal presentation. This was at least partly related to the leveling influence of cesarean sections, as ean be seen by excluding the cases of cesarean section thereby causing the perinatal mortality for breech presentation to be 25 per cent while for vertex presentation it is 32 per cent. This confirms the contention of Bourgeois3 that the irregular soft breech is less liable to compress the cord than the harder rounded yertex presmtation, provided the rhild is drlivered vaginally. TABLE
VI.
FETAL PRESENTATION FETAL MORTALI'rY
Vertex Breech Transverse or compound Face
CASES
NO.
37 18 16
0
1
4
4 1
INCIDENCE (
o/o)
24.3 22.2 25.0 100.0
The perinatal mortality for transverse or compound presentations, even after the cases of cesarean section are excluded, was still only 3-i per crnt
123R
\n •. ]. Obst. & Gynec.
December, 1959
because almost half the cases occurred in the second of twins. When thmw cases relating to the second of twins were exc~luded, it was found that of thl· 7 remaining treatable infants who wrt'f' deliverPd vaginally 4 died.
4. Contracted pelvis: Three fetal perinatal deaths occurred iu the 6 cases of pelvic contraction in which the cord prolapsed. This high fetal loss was due to the fact that attempted vaginal delh·er;- was more difficult than had been anticipated. The 3 living children werP ali deliwred hr cesm·pan .-;Pction. 5. Multiple pregnancy: The risk of cord prolapse was markedly increased in multiple pregnancy, especialh· for thP first child. The first child's cord prolapsed once in ewry. ~4 cases of multiple pregnane.,-. whereas the l'isk fm tlw second child was 1 in 41. The cord of the first child pt·olapscd on 11 oeeasions. with a 27.3 per cent perinatal mortalit,,·. The second c·hild's l'ord prolapsed on 7 occasions but there were no fetal deaths. These mortality Jigm'('S agn·(· with those of Fenton and D'Esopo" and arr, of comse. arconnted for by the fa<-t that prolapse of the second rhild's cord orenrs nmlrr idt>al cin·mnstanl'('S. 6. Placenta previa: Five treatable cases of plaeenta 1n·evia assoc·iatt•cl with prolapse of the cord oecurred, and ~ of the ('ases had a low insc·rtion o[ the eord. Three of the 5 mothers were tlelin~rcd of liYing· rhildrrn hy r·esarra11 section; of the 2 delivrrerl vaginally, 1 diPd. 7. Fetal abnormality: l11 1his s!·ries of ra~ws, S.;i per eent of the babies had abnormalities incompatihh· with life. Thercfon•. hdore a cesarean srction is performed for prolapse of the cord, c•m·dnl elinical examination should ahvays he carried out to rxclmlt• the• c•ommm1 J'c>tal ahnormalitirs of anl'nePplwly ancl hydrorephalr. Treatment
In,itiaL 'I't·eatmeni.-Postural or digital elevation of the presenting part tP relieve the pressure on the prolapsrd eon! is frequently advispd as an interim measure while the institution of mon~ radical methods of treatment is awaitc•cL Elevation of the presenting pat-t was specifically mentioned only 14 times in the case records, but I feel sure it was used far more frequently. 'fhis initial therapy would appear to be effective since no child was lost during the waiting period and all the cases of fetal distress improved, except one, whirh O(·eurrecl in a grand multipara having strong uterine eontractions, who waited llh hours for a cesarean section to be carried out. On this occasion obviously too much was demanded of this initial me! hod of trt'atnH'nt. Active Treatment.-Table VII depicts the various methods ntilized in the delivery of the treatable cases of prolapse of the cord at Saint Mary's Hospitals from 1951 to 1955, together with the inridence and pt•rinatal fetal mortalit~· associated with each method. Those patients in whom the prolapsed cord was diagnosed at full cervical dilatation were all delivered vaginally and are marked by an asterisk ( *) in Table VII. In this type of case the average perinatal mortality rate was 17.5 per cent. Analysis of the 7 perinatal deaths which occurred shows that ~ wen· associated with contracted pelves which caused difficulty in forceps delivery. resulting in fetal death from asphyxia; ~ of the fetal deaths were associated with delay in the institution of treatment; 2 other deaths occurred in markedl~ premature babies (2 pounds, 2 ounces, and 3 pounds, 4 ounces), and one fetal asphyxial death occurred despite an apparently rapid and easy forceps delivery. It would therefore appear that still further improvement in the fetal survival rate could have been obtained in this group of cases by immediatel;proceeding with rapid vaginal delivery, provided this was reasonably easy; but in those cases complicated by pelvic contraetion a rapid cesarean section holds out the best chance of fetal survival.
1239
PRESENTATION AND PROLAPSE OF UMBILICAL CORD
Volume 7S Number 6
TABLE
VII.
METHODS OF DELIVERY
1931 TO 1935
1951 TO 1955
CASES
I %
0 3
0 37.5
16.7
1
14.3
3
2
7.1 4.8
2 2
66.7 100.0
3
7.1
1
33.3
100
7.1
3
100
1
100
2.4
1
100
1
100
2A
0
1
0 100
b.v
18 22
25
30.6
1 5
22.7
1 3 8
1.4 4.2 11.1
0 0
0
0 0
5 3
6.9 4.2
2 0
3
4.2
3
100
1
1.4
1
1
1.4 1.4
~
±
2.8 :3.6
72
2 2 18
I %
I
NO.
NO.
Cesarean sectwn Forceps delivery* Forceps delivery through incompletely dilated cervixt Assisted breech delivery* Breech extraction* Breech extraction through incompletely dilated cervixt Internal version and breech extraction* Cord replacement, internal or bipolar version, cervix plugged with % breech, then breech extraction through incompletely dilated cervix t Cord replacement; internal or bipolar version, and cervix plugged with % breech t Cord replacement and cervix plugged with % breech t Cord replacement and bipolar cephalic version t Cord replacement t [nternal version and high forceps* Failed forceps, later craniotomyt Intrauterine death after admission, later craniotomy Intrauterine death after admission. later deli verv bY natural forceR Vertex delivery natural forcps* Total
FETAL MORTALITY
4 8
9.5 19.0
0
7
40.0 0
5.6
100 50
2.± l
2.4
~
±.8
2
100
~A
1
100
7.1 4.8
3 1
100 50.0
3 42
l
100
22
• Patients delivered vaginally at full cervical dilatation. (See text.) tCases treated by vaginal manipulation when prolapsed cord was diagnosed at incomplete cervical dilatation. (See text.)
Those patients treated by vaginal manipulations when the prolapsed cord was diagnosed in association with an incompletely dilated cervix and a living fetus are marked by a dagger ( t) in Table VII. The average perinatal mortality for these cases was 67 per cent. It is in this group of cases that most improvement in the perinatal survival rate is to be looked for in the future, b:· more frequent recourse to cesarean section. The vaginal manipulations utilized in these cases with incomplete dilatation of the cervix were either vaginal delivery through the undilated cervix or replacement of the cord or a combination of both. Vaginal delivery through an incompletely dilated cervix was performed for prolapse of the cord on 9 occasions with 5 perinatal deaths. All thesr perinatal deaths were related to i.Jreech extraction through an undilated cervix although in ~ cases there was also marked prematurity. This method of treatment, therefore, carried with it the high fetal perinatal mortality of :i6 per cent. The very definite risk of damage to the mother by this treatment is emphasized when it is found that the maternal genital infection rate in these eases is 3¥2 times that for all the other cases of prolapsed cord. Replacement of the prolapsed cord was attempted on 6 occasions. It succeeded in 4 cases but failed in L and the prolapse recurred in another case. All the babies died, but in 3 the immediate cause of death was breech extraction +h.,..,.,.,....,..}.... n,.. """'..:J~ln.j-1'\.;J fliYl'I'U~,.. nVlrln..,.-.+Gl:,.·,an l·.IlJ. VUOJt
a.r.1
U.J..IU.tJ.aL
"~A
honnHCII'\.
n.f .LV1.t«--L -fnfnl
u.ttuv-L tJun.L.-.u_ Pv'Vuu.ov v.1...
fl;~tPfl.Oet
u.tot.<.t.v~.
It is unfortunate that manual replacement of the prolapsed cord, which is such an eminently reasonable method of treatment, carries such a poor
1~40
NORBUHN
·\m.
J. Obst.
& Gynec. December, !959
chance of fetal survival. Tn the cases under review, cotton gauze was utilized in the replacement, but it is doubtful if the cord was always fully replaced above both the presenting part and the retraetion ring, into the upper segment of the uterine cavity. Probably the cord had not been fully replaced in thos<• cases where the prolapse recurred, or fetal dist.res:-; developed shortly aftrr apparently successful reposition. Perhaps it is technically too difficult to replace the cord on every occasion completely into the upper uterine segment. especially for the junior obstetrician, who nowadays has less opportunity of performing difficult vaginal maneuvers, but who may su<1clenly be called upon to deal with this emergency. It may be of interest to here record a case which occurred in 1954, when a fetus whose heart became inaudible and whose eord had ceased to heat was delivered alive. At routine examination of a multiparous patient in lahot·. the fetal heart sounds suddenly ceased. Vaginal examination revralcd a fully dilated cervix through which was protruding a nonpulsatile cord. A mpid and easy mhlcavity foreeps drlivcry r·esultcd in the hirth of a living lwalthy child.
Comparison With 1931 to 1935 Prolapse of the cord oc<~urrcd on G4 oeeasion,; f!'om 1!l:3l to 1935, giving an incidence in "hooked" easrs of 1 in 201 and in ''emergency" eases of 1 in 73. .Just over half of the c·ascs wc·n· c·mcrgency admissions and many of the babies werr already dead on admission, leaving 42 "trratahle" cases. The• correctrd fetal perinatal mortality for the treatable eases was G2.4 prr cent, which is rathrt· more than double the corresponding figure for 1951 to 1955. If we consider how this fetal perinatal mortality has hccn lowered over the 20 year interval, it may point the way to a fm·ther reduction of the perinatal mortality in the future. In Table VII are listed methods utilized for the delivery of treatablr cases of prolapse of the cord during 1931 to 1935 as well as the as~wciatrd fetal perinatal mortality rates. Those patients delivered vaginally at full cervical dilatation 1luring 19~~ I to 1935 are marked hy an asterisk ('7') in 'l'ahle VII. lf we compare thefw cases with the similar cases occurring during 1951 to 1955 it will be seen that the incidence of the cases is the same hnt the perinatal mortality for 1931 to 1935 was 40 per cent while during the period 1951 to 1955 it was 17.5 per cent. This fall in perinatal mortality during the 20 year interval is mainly related to a change in etiology, especially in regard to pelvic contraction, with which 20 per cent of the cases of prolapsed cord were associated from HJ31 to 1935, almost treble the incidence from 1951 to 1955. In those patients deliverrd vaginally at full cervical dilatation from 1931 to 1935, 4 of the 8 perinatal deaths were associated with pelvic contraction. This again emphasizes thr need to carefully exclude pelvic contraction before em harking on vaginal delivery for prolapse of the cord. . . Those cases treated by vaginal manipulations during 1931 to 193fi whrn the prolapsed cord was diagnosed at incomplete cervical dilatation, are designated by a dagger ( t) in Table VII. When these cases are compared with the similar cases occurring during the later quinquennium, it is seen that the perinatal mortality has remained very close to 70 prr cent, but the incidenct' of these eases has decreased from 3:3.3 per cent in 1931 to 1935 to 16.7 per cent in 1951 to 1955. This fall in incidence of vaginal delivery has, of course, been accompanied by a parallel increase in the cesarean section rate during the 20 year interval, which has resulted in halving the perinatal mortality for all those cases of prolapsed cord diagnosed at incomplete cervical dilatation. This undoubtedly indicates one of the main paths we may follow in order to save the lives of more babies in the fuinre.
Volume i8 "'umber 6
PRESEN'l'A'l'IO.K ANil l'HOLAPHE OP F.\1HILICAL UORJ)
1241
Another important factor has also tended to produce a general elevation of the fetal perinatal mortality rate for 1931 to 1935. Fifty-three per cent of the patients admitted during this period were emergency cases, and many of them were in poor general condition. Indeed 16 of these babies were already dead and 2 of the mothers died from shock and infection shortly after admission. Presumably an appreciable number of the babies, although alive on admission, were not fit to stand more than the easiest of deliveries. I fe<'l sure this factor contributed to a general elevation of the fetal mortality during the period J 931 to 1985, but to what extent I am unable to asc<'rtain from the notes. 'l'he incidence of the ca~ws diagnosed at each level of cervical dilatation has remained remarkably constant during both 5 year periods and therefore this factor has had no influence 011 the changed perinatal mortality.
Comment It is apparent from what has lw0n said above that if the fetal perinatal survival rate is to be further increasetl, continuous vigilance must be exer·eised with the possibility of prolapse of the cord ever at the back of one's mind, and should the possibility materialize, then, in the main, only 2 lines of treatment should be followed: ( 1) immediate vaginal deliYery, provided the cervix is fully or almost fully dilated and delivery is expected to be easy; (2) immediate cesarean section if the cenix is incompletely dilated or vaginal delivery is expected to be difficult for any other reason, such as pelvic contraction. I would like to plead that the full equipment for a cesarean section should always be kept sterilized and ready for immediate use should such an emergency as prolapse of the cord arise. The cesarean section could, however, be performed in the labor ward if the operating theater were engaged. It is, of course, important to continue with the initial treatment while preparations are being made for the operation and to auscultate th(• fda] heart again immediately before the operation. The objection to further increasing the cesarean section rate lies in the dsk to the mother. Marshall and Cox 6 have shown that during the first 24 hours of Jabot· the maternal risk is less than 0.35 per cent, and it is within this time limit that all cases of prolapsed cord were diagnosed at Saint Mary's Hospitals during 1951 to 1955 (except for 2 cases in each of which the baby weighed less than 3 pounds). Most mothers would, I feel sure, gladly accept this small risk in order to obtain a living child. Obviously if the risk to the mother from cesarean section is markedly increased, or the fetus has a poor chance of survival, an alternative method of treatment should be adopted. provided this carries a lower maternal risk. The alternatiYe courses of action are: 1. Replacement of the cord, which carries a high fetal perinatal mortality, and its usefulness is thrrdore restricted to those cases in which the chance of fetal survival is already doubtful, as in the case of marked prematurity. :2. Vaginal aelivHy through the undilated cervix or after manual dilatation of the eervix, which is associated with a high perinatal mortality and the risk of serious damag·e to the mother. The place of this treatment in modern obstetrical practice can be taken more safely by cesarean section. :3. An expectant poliey is, of eourse, followed if the fetus is dead, or, very occasionally, in the treatable case when the maternal condition is so unsatisfactory (e.g., cardiac failure) that replacement of the cord under general anesthesia carries a maternal risk ont of proportion to the poor chance of fetal survival.
1242
NORBURN
Am. J. Obst. & Gynec. December. 1959
Summary An analysis is presented of 84 cases of prolapse of the cord occurring from 1951 to 1955 at Saint Mary's Hospitals, and these have later been compared with the 64 cases which occurred during 1931 to 1935. The incidence including the relationship to maternal age and parity has been considered. Malpresentation and prematurity were the most eommon etiological factors. The diagnosis has been discussed. It is doubted if spasm of the cord vessels plays such an important role in causing fetal death as has been suggested elsewhere. The corrected fetal perinatal mortality for 1951 to 1955 was 25 per cent. Presentation of the cord carries a similar fetal risk to prolapse of the cord. Certain important factors in relation to perinatal mortality have been considered. The treatment, both initial and active, has been discussed and conclusions drawn as to how further reductions may be made in fetal perinatal mortality. All the babies died when replaccmrnt of the cord was performed. Immediate vaginal delivery through the incompletely dilated cervix carried a perinatal mortality of 56 per cent together with a high maternal rnorbidity rate. It would appear that the fetal perinatal mortality may be further lowl't·ed by following 2 main lines of treatment, eithf'r immediate vaginal delivt>ry. if this is easy, or immediate cesarean seetion. All treatable cases, except in 2 markedly premature infants, of prolaps<· of the cord at Saint Mary's Hospitals from 1951 to 1955 occurred within the first 24 hours of labor, when the maternal risk from cesarean section is low. I wish to express my thanks to the chairman and members of the Medical Committe,-, of Saint Mary's Hospitals for permission to quote from the Hospital Records. l am also greatly indebted to Professor W. I. C. Morris for his invalnahle help and criticism throug-hout the preparation of this paper.
References 1. Stephens, J.: Lancet 2: 196, 1847. 2. Fenton, A. N., and D'Esopo, D. A.: AM. J. 0BST. & GYNEC. 62: 52, lfl.)J. 3. Bourgeois, G. A.: AM. J. 0BST. & GYNEC. 41: 837, 1941.
4. Rhodes, P.: Proc. Roy. Soc. Med. 49: 937, 1956. 5. Moir, J. Chasaar: Munro Kerr's Operative Oh,;tetrics, ed. 6, London, 1956. Baillien·. Tindall & Cox, p. 262. 6. Marshall, C. M., and Cox, L. W.: Tr. Brit. Cong. Obst. & G.vnaee_ 12: 30. 19:)<1.
NoRBURN,
M.B., CH.B., M.R.C.O.G.,
NORTHAMPTON, ENGLAND
(From St. Mary's Hospitals, Manchester, England)
( ) VER 100 years ago James Stephens 1 wrote, "The fatal results, as regards '--"" the life of the child, so frequently observed when the cord descends during labor, renders it very desirable to endeavour to lessen the excessiYe mortality shown in the records of the profession." These words would still appear to he true today, when the fetal mortalit,\' is authoritatively quoted as varying from 50 to 60 per cent. 5 It is the purpose of this papet· to investigate those cases in which prolapse of the fetal umbilical cord occurred and to attempt to learn how the related fetal perinatal mortality may be further reduced. The material for this paper has heen obtained from a study of all the cases of prolapse or presentation of the cord occurring in Saint Mary's Hospitals during the 5 year period, 1951 to 1955. This quinquennium is later compared with the corresponding period 20 years earlier.
Incidence Presentation or prolapse of the cord occurred 84 thnes in 16,487 consecutive deliveries from 1951 to 19fl5 at St. Mary's Hospitals, a total incidence of 0.51 per cent or 1 in 196. The incidence in "booked" cases was 0.43 per cent or 1 in 232, while in "emergency" cases it was 1.12 per cent or 1 in 89. The emergency cases accounted for 24 per cent of the total admissions. A total of 1,031 fetal perinatal deaths occurred during this period and of these, 2.9 per cent or 1 in 34 were related to pr('Sentation or prolapse of tht' cord. Table I shows the incidence of prolapse of the cord in relation to maternal ago and parity. I.1et us exclude for the moment the very young nulliparous gToup where the high incidence of prolapse of the cord is related to the high frequency of prematurity ( 60 per cent). It is now seen that the risk of corr1 prolapse increases as either maternal age or parity increases. IT owever, the greatest risk of cord prolapse at each parity changes from the oldest age group in the nulliparous patients to the youngest age group in the grand multiparous patients. This very high risk (1 in 21) in the youngest age group of tht> grand multiparas demonstrates one of the various disadvantages associatf;d with the too frequent recurrence of pregnancy.
Etiological Factors The incidence of the various etiological factors for the 5 year period is shown in Table II. The factors, of course, may be multiple in any one ease. 1234
1235
PRESJ;;NTA'l'ION AND PROLAPSE OF UMBILICAL CORD
\ olume 78 :\'umber 6
'l'ABLE I.
INCIDENCE OF PROLAPSE OF THE CORD IN RELATION TO AGE AND PARITY
Para 0
UNDER 20 5 in 414 (I in 83)
20-24 6 in 2074 (1 in 346)
25-29 4 in 1865 (1 in 466)
Para i
0 in 46
3 in 512 (1 in 171)
4 in 914 (1 in 228)
Para ii
0 in
4
1 in 117 (1 in 117)
Para iii
0 in
1
0 in
23
Para iv
0 in
0
0 in
1
Para v and over Total
Oin
0
0 in
4
5 in 465 in 93)
(1
10 in 2731 (1 in 273)
AGE (YEARS) 30-34 5 in 1024 (lin 205)
35-39 2 in 555 (1 in 277)
OVER 40 1 in 195 (1 in 195)
TOTAL 23 in 6127 (1 in 266)
4in 751 (1 in 188)
5in 479 (1 in 96)
4 in 166 (1 in 41)
20 in 2868 (1 in 143)
3 in 398 (1 in 133)
4in 401 (1 in 100)
(1 in
5 in 291 58)
1 in 104 (1 in 104)
14 in 1315
1 in 132
(1 in 132)
6 in 200 (1 in 33)
3 in 140 (1 in 47)
0 in 77
lOin 573 57) (lin
1 in (1 in
56 56)
2 in (1 in
93 46)
1 in 105 (1 in lOti)
0 in 43
4in 298 (1 in 74)
Oin
39
6 in 128 (1 in 21) 27 in 2597 96) (1 in
4 in 16fl ( 1 in 42) 20 in 17:i!l (1 in R71
3 in 130 (1 in 43) 9in715 ( 1 in 79)
13 in 440 ( 1 in 34)
] :lin :l404 (1 in :Zti2)
I
I
(1 in
Malpresentation was by far the commonest single predisposing faet01·. Prolapse of the cord occurred only once in ever·y 379 eases of vertex presentation, but when the fetal presenting part fitted the lower segment of the uterus less accurately, the incidence rose markedly to 1 in 59 with face presentation. 1 in 30 with breech presentation, and 1 in 6 with transverse lie or compound presentation. It is interesting to see how infrequently prolapse of the cord is predisposed to by pelvic contraction or placenta previa, but, as will be seen later, their importance in relation to fetal perinatal mortality far outweighs their etiological frequency. TABI,E II.
TNCIDENCE OF' ETIOWG!CAL FACTOltS
ETIOLOGICAL Jo'ACTORS
--~-Malpresentation
<
----~-
Prematurity ( 51;2 pound~) Multiple pregnancy Grand multipara (Para v+) Ri!lh mobile head when membranes ruptured Hvdramnios ~ Piacenta previa Fetal abnormality Contracted pelvis Obstetrical manipulations Obliquity of uterus Vomiting under anesthesia Unknown
NO.
INCI-DENCE ( o/o)
32
38.1 23.fi J 5.5 15.5 9.5 1'!.3 8.3 7.1 5.9 1.1 1.1 5,9
---:vf ___'-----;o5c;-1.-;;2--'----'--HI
13 13 8 7 i H
5
1
1
5
Five eases of prolapse of the eord oecurred dm·ing the course of obstetrical manipulations. T,vo of these oecurred during vaginal n1anipulations at the time of attempted forceps delivery (one of them before admission to hospital) ; one followed artificial rupture of the forewaters in the presence of a high and mobile head; another occurred when labor was induced with a hydrostatic bag which displaced the presenting part and allowed the cord to prolapse; and the other was a case of transverse lie with ruptured forewaters whirh was treated by internal version followed by plugging the cervix with the half breech, but it was discovered later that this trapped the cord between the cervix and breech. Diagnosis Prolapse of the cord was diagnosed on 84 occasions, and on 28 of these (:3:3.0 per cent) the diagnosis was made only when the cord presenterl at the
94)
1236
NORBURN
\m_ .L ObsL & Gynec. December, 1959
vulva. After excluding the 6 cases in which the child was delivered almost immediately after discovery of the cord at the vulva, the corrected perinatal mortality was 23.5 per cent. This compares satisfactorily with the eonectcd perinatal mortality of 25 per cent for all cases. It is therefore doubtful if spasm of the cord vessels plays such an important role in causing fetal death as has been suggested• since presumahly the vascular spasm would he most marked in those cords which prolapse outside the vulva. In the remaining cases, the prolapsed cord was found on digital pelvic examination, but in only 12 cases (1±.3 per cent) was the vaginal examination performed for fetal distress. Most comn1onl.Y (4'7.6 per cent of all cases) the prolapsed cord was found during routine vaginal examination with the possibility in mind; following spontaneous rupture of the membranes (20 cases); while the course of labor was being assessed (14 cases); or following delivery of the first of twins (6 cases). In 4 cnses (4.8 per cent) the prolapsed cord was found during vaginal manipulations.
Prognosis
A. Maternal Mortality.-There were no maternal deaths associated with prolapse of the cord during the period under review. B. Fetal Perinatal Mortality.-There were 30 fetal perinatal deaths due to prolapse of the cord from 1951 to 1955, giving a perinatal mortality rate of 1.9 per 1,000 deliveries. The value of antenatal care even in this obstetrical emergency is seen when the fetal perinatal mortality for booked cases is found to be 32.3 per cent 'l:hile that for the emergency cases is 47.4 per cent. Examination of Table III will show how the corrected fetal perinatal mortality of 25 per cent has been obtained frorn a gross perinatal n1ortalit..v of 35.7 per cent. It will be noted that the correction has been made only in order to obtain the perinatal mortality for "treatable" cases. The treatable cases arc those cases i11 "\vhich the fetus is alive and nor1nal \vhen the patient is admitted to hospital. No correction has bern made for prematurity, except in so far as all the cases were at or paRt the twenty-righth week of gestation. TABLE
III.
CORRECTED FETAI, PERINATAL MORTALI'l'Y
I ____ NO.
Total cases of prolapse of cord Number of perinatal deaths Less fetal abnormalities incompatible with life 7 Less babies dead on admission but otherwise normal 5 Remaining perinatal deaths Total babies normal and alive on admission
FETAL MORTALITY
__ I _ ---~% I ___ >
84
:-w
18
~5.0
72
In the following analysis only treatable cases have been considered. Presentation of the cord was found on 10 occasions. This precursor of the prolapsed cord caused 2 fetal deaths before the membranes ruptured. Three of the 8 remaining patients were rapidly and easily delivered vaginally after rupture of the forewaters, while 5 were delivered by cesarean section. It will therefore be seen that at Saint Mary's Hospitals presentation of the cord is considered to be almost as serious for the fetus as true prolapse of the cord and is certainly not regarded so complacently as it is in most textbooks.
PRESENTATTOK AKD PROLAPkE OF FJ:rBILICAL CORD
Volume iR
~nmher 6
1237
Important Factors in Relation to Fetal Perinatal Mortality.1. Degree of cervical dilatation: This is a Yery important factor in relation to the fetal perinatal mortalit~-, as can be seen from Table IV. TABLE
IV.
DEGREE OF CERVICAl, DILATATION FETAL MORTALITY
CASES DILATATION OF CERVIX WHEN PROLAPSE DIAGNOSED
INC'!DEKCE
xo.
Fully dilated '!14 dilaterl lf2 dilated %dilated
I
40
55.6
-i
5.6 1 ~.ii
0
19
INCIDENCE
NO.
(%)
(%) 17.5 50.0 66.7
6
15.8
3
%.4
When the cervix is fully dilated, the fetus can usually be rapidly, easily, and safely delivered vaginally, but, with an incompletely dilated cervix, immediate vaginal delivery is appreciably more difficult; there is a much greater risk of fetal death, and replacement of the cord also carries a high fetal mortality. The perinatal mortality, therefore, falls sharply as the cervical dilatation increases. When the cervix was only slightly dilated, however, the perinatal mortality was markedly diminished, and the fetal survival rate was better than with the fully dilated cervix. This was due to the frequent use of abdominal delivery in this type of ease. It is noteworthy that all the l6 living children obtained from those cases where the cervix was only slightly dilated were delivered by cesarean section. 2 ..fi'etal maturity: Table V reveals the importance of fetal maturity in relation to the perinatal mortality from prolapse of the cord. The premature baby, as always, is adversely affected by any complication of labor. 'l'ABLE
V.
FETAL MATt'RlTY ~ 1 ~'1'..:'\.L
Mature normal babies PrPmature normal babies (
< 5~t&
pounds)
CASBS
::<10.
41
10
~5
K
rv£0RT.l1.. LITY
lNC!IlEKCe (
o/o)
~u :1~.0
3. Fetal presentation: It is surprising to find on referring to Table VI that the perinatal mortality was not appreciably influenced by the fetal presentation. This was at least partly related to the leveling influence of cesarean sections, as ean be seen by excluding the cases of cesarean section thereby causing the perinatal mortality for breech presentation to be 25 per cent while for vertex presentation it is 32 per cent. This confirms the contention of Bourgeois3 that the irregular soft breech is less liable to compress the cord than the harder rounded yertex presmtation, provided the rhild is drlivered vaginally. TABLE
VI.
FETAL PRESENTATION FETAL MORTALI'rY
Vertex Breech Transverse or compound Face
CASES
NO.
37 18 16
0
1
4
4 1
INCIDENCE (
o/o)
24.3 22.2 25.0 100.0
The perinatal mortality for transverse or compound presentations, even after the cases of cesarean section are excluded, was still only 3-i per crnt
123R
\n •. ]. Obst. & Gynec.
December, 1959
because almost half the cases occurred in the second of twins. When thmw cases relating to the second of twins were exc~luded, it was found that of thl· 7 remaining treatable infants who wrt'f' deliverPd vaginally 4 died.
4. Contracted pelvis: Three fetal perinatal deaths occurred iu the 6 cases of pelvic contraction in which the cord prolapsed. This high fetal loss was due to the fact that attempted vaginal delh·er;- was more difficult than had been anticipated. The 3 living children werP ali deliwred hr cesm·pan .-;Pction. 5. Multiple pregnancy: The risk of cord prolapse was markedly increased in multiple pregnancy, especialh· for thP first child. The first child's cord prolapsed once in ewry. ~4 cases of multiple pregnane.,-. whereas the l'isk fm tlw second child was 1 in 41. The cord of the first child pt·olapscd on 11 oeeasions. with a 27.3 per cent perinatal mortalit,,·. The second c·hild's l'ord prolapsed on 7 occasions but there were no fetal deaths. These mortality Jigm'('S agn·(· with those of Fenton and D'Esopo" and arr, of comse. arconnted for by the fa<-t that prolapse of the second rhild's cord orenrs nmlrr idt>al cin·mnstanl'('S. 6. Placenta previa: Five treatable cases of plaeenta 1n·evia assoc·iatt•cl with prolapse of the cord oecurred, and ~ of the ('ases had a low insc·rtion o[ the eord. Three of the 5 mothers were tlelin~rcd of liYing· rhildrrn hy r·esarra11 section; of the 2 delivrrerl vaginally, 1 diPd. 7. Fetal abnormality: l11 1his s!·ries of ra~ws, S.;i per eent of the babies had abnormalities incompatihh· with life. Thercfon•. hdore a cesarean srction is performed for prolapse of the cord, c•m·dnl elinical examination should ahvays he carried out to rxclmlt• the• c•ommm1 J'c>tal ahnormalitirs of anl'nePplwly ancl hydrorephalr. Treatment
In,itiaL 'I't·eatmeni.-Postural or digital elevation of the presenting part tP relieve the pressure on the prolapsrd eon! is frequently advispd as an interim measure while the institution of mon~ radical methods of treatment is awaitc•cL Elevation of the presenting pat-t was specifically mentioned only 14 times in the case records, but I feel sure it was used far more frequently. 'fhis initial therapy would appear to be effective since no child was lost during the waiting period and all the cases of fetal distress improved, except one, whirh O(·eurrecl in a grand multipara having strong uterine eontractions, who waited llh hours for a cesarean section to be carried out. On this occasion obviously too much was demanded of this initial me! hod of trt'atnH'nt. Active Treatment.-Table VII depicts the various methods ntilized in the delivery of the treatable cases of prolapse of the cord at Saint Mary's Hospitals from 1951 to 1955, together with the inridence and pt•rinatal fetal mortalit~· associated with each method. Those patients in whom the prolapsed cord was diagnosed at full cervical dilatation were all delivered vaginally and are marked by an asterisk ( *) in Table VII. In this type of case the average perinatal mortality rate was 17.5 per cent. Analysis of the 7 perinatal deaths which occurred shows that ~ wen· associated with contracted pelves which caused difficulty in forceps delivery. resulting in fetal death from asphyxia; ~ of the fetal deaths were associated with delay in the institution of treatment; 2 other deaths occurred in markedl~ premature babies (2 pounds, 2 ounces, and 3 pounds, 4 ounces), and one fetal asphyxial death occurred despite an apparently rapid and easy forceps delivery. It would therefore appear that still further improvement in the fetal survival rate could have been obtained in this group of cases by immediatel;proceeding with rapid vaginal delivery, provided this was reasonably easy; but in those cases complicated by pelvic contraetion a rapid cesarean section holds out the best chance of fetal survival.
1239
PRESENTATION AND PROLAPSE OF UMBILICAL CORD
Volume 7S Number 6
TABLE
VII.
METHODS OF DELIVERY
1931 TO 1935
1951 TO 1955
CASES
I %
0 3
0 37.5
16.7
1
14.3
3
2
7.1 4.8
2 2
66.7 100.0
3
7.1
1
33.3
100
7.1
3
100
1
100
2.4
1
100
1
100
2A
0
1
0 100
b.v
18 22
25
30.6
1 5
22.7
1 3 8
1.4 4.2 11.1
0 0
0
0 0
5 3
6.9 4.2
2 0
3
4.2
3
100
1
1.4
1
1
1.4 1.4
~
±
2.8 :3.6
72
2 2 18
I %
I
NO.
NO.
Cesarean sectwn Forceps delivery* Forceps delivery through incompletely dilated cervixt Assisted breech delivery* Breech extraction* Breech extraction through incompletely dilated cervixt Internal version and breech extraction* Cord replacement, internal or bipolar version, cervix plugged with % breech, then breech extraction through incompletely dilated cervix t Cord replacement; internal or bipolar version, and cervix plugged with % breech t Cord replacement and cervix plugged with % breech t Cord replacement and bipolar cephalic version t Cord replacement t [nternal version and high forceps* Failed forceps, later craniotomyt Intrauterine death after admission, later craniotomy Intrauterine death after admission. later deli verv bY natural forceR Vertex delivery natural forcps* Total
FETAL MORTALITY
4 8
9.5 19.0
0
7
40.0 0
5.6
100 50
2.± l
2.4
~
±.8
2
100
~A
1
100
7.1 4.8
3 1
100 50.0
3 42
l
100
22
• Patients delivered vaginally at full cervical dilatation. (See text.) tCases treated by vaginal manipulation when prolapsed cord was diagnosed at incomplete cervical dilatation. (See text.)
Those patients treated by vaginal manipulations when the prolapsed cord was diagnosed in association with an incompletely dilated cervix and a living fetus are marked by a dagger ( t) in Table VII. The average perinatal mortality for these cases was 67 per cent. It is in this group of cases that most improvement in the perinatal survival rate is to be looked for in the future, b:· more frequent recourse to cesarean section. The vaginal manipulations utilized in these cases with incomplete dilatation of the cervix were either vaginal delivery through the undilated cervix or replacement of the cord or a combination of both. Vaginal delivery through an incompletely dilated cervix was performed for prolapse of the cord on 9 occasions with 5 perinatal deaths. All thesr perinatal deaths were related to i.Jreech extraction through an undilated cervix although in ~ cases there was also marked prematurity. This method of treatment, therefore, carried with it the high fetal perinatal mortality of :i6 per cent. The very definite risk of damage to the mother by this treatment is emphasized when it is found that the maternal genital infection rate in these eases is 3¥2 times that for all the other cases of prolapsed cord. Replacement of the prolapsed cord was attempted on 6 occasions. It succeeded in 4 cases but failed in L and the prolapse recurred in another case. All the babies died, but in 3 the immediate cause of death was breech extraction +h.,..,.,.,....,..}.... n,.. """'..:J~ln.j-1'\.;J fliYl'I'U~,.. nVlrln..,.-.+Gl:,.·,an l·.IlJ. VUOJt
a.r.1
U.J..IU.tJ.aL
"~A
honnHCII'\.
n.f .LV1.t«--L -fnfnl
u.ttuv-L tJun.L.-.u_ Pv'Vuu.ov v.1...
fl;~tPfl.Oet
u.tot.<.t.v~.
It is unfortunate that manual replacement of the prolapsed cord, which is such an eminently reasonable method of treatment, carries such a poor
1~40
NORBUHN
·\m.
J. Obst.
& Gynec. December, !959
chance of fetal survival. Tn the cases under review, cotton gauze was utilized in the replacement, but it is doubtful if the cord was always fully replaced above both the presenting part and the retraetion ring, into the upper segment of the uterine cavity. Probably the cord had not been fully replaced in thos<• cases where the prolapse recurred, or fetal dist.res:-; developed shortly aftrr apparently successful reposition. Perhaps it is technically too difficult to replace the cord on every occasion completely into the upper uterine segment. especially for the junior obstetrician, who nowadays has less opportunity of performing difficult vaginal maneuvers, but who may su<1clenly be called upon to deal with this emergency. It may be of interest to here record a case which occurred in 1954, when a fetus whose heart became inaudible and whose eord had ceased to heat was delivered alive. At routine examination of a multiparous patient in lahot·. the fetal heart sounds suddenly ceased. Vaginal examination revralcd a fully dilated cervix through which was protruding a nonpulsatile cord. A mpid and easy mhlcavity foreeps drlivcry r·esultcd in the hirth of a living lwalthy child.
Comparison With 1931 to 1935 Prolapse of the cord oc<~urrcd on G4 oeeasion,; f!'om 1!l:3l to 1935, giving an incidence in "hooked" easrs of 1 in 201 and in ''emergency" eases of 1 in 73. .Just over half of the c·ascs wc·n· c·mcrgency admissions and many of the babies werr already dead on admission, leaving 42 "trratahle" cases. The• correctrd fetal perinatal mortality for the treatable eases was G2.4 prr cent, which is rathrt· more than double the corresponding figure for 1951 to 1955. If we consider how this fetal perinatal mortality has hccn lowered over the 20 year interval, it may point the way to a fm·ther reduction of the perinatal mortality in the future. In Table VII are listed methods utilized for the delivery of treatablr cases of prolapse of the cord during 1931 to 1935 as well as the as~wciatrd fetal perinatal mortality rates. Those patients delivered vaginally at full cervical dilatation 1luring 19~~ I to 1935 are marked hy an asterisk ('7') in 'l'ahle VII. lf we compare thefw cases with the similar cases occurring during 1951 to 1955 it will be seen that the incidence of the cases is the same hnt the perinatal mortality for 1931 to 1935 was 40 per cent while during the period 1951 to 1955 it was 17.5 per cent. This fall in perinatal mortality during the 20 year interval is mainly related to a change in etiology, especially in regard to pelvic contraction, with which 20 per cent of the cases of prolapsed cord were associated from HJ31 to 1935, almost treble the incidence from 1951 to 1955. In those patients deliverrd vaginally at full cervical dilatation from 1931 to 1935, 4 of the 8 perinatal deaths were associated with pelvic contraction. This again emphasizes thr need to carefully exclude pelvic contraction before em harking on vaginal delivery for prolapse of the cord. . . Those cases treated by vaginal manipulations during 1931 to 193fi whrn the prolapsed cord was diagnosed at incomplete cervical dilatation, are designated by a dagger ( t) in Table VII. When these cases are compared with the similar cases occurring during the later quinquennium, it is seen that the perinatal mortality has remained very close to 70 prr cent, but the incidenct' of these eases has decreased from 3:3.3 per cent in 1931 to 1935 to 16.7 per cent in 1951 to 1955. This fall in incidence of vaginal delivery has, of course, been accompanied by a parallel increase in the cesarean section rate during the 20 year interval, which has resulted in halving the perinatal mortality for all those cases of prolapsed cord diagnosed at incomplete cervical dilatation. This undoubtedly indicates one of the main paths we may follow in order to save the lives of more babies in the fuinre.
Volume i8 "'umber 6
PRESEN'l'A'l'IO.K ANil l'HOLAPHE OP F.\1HILICAL UORJ)
1241
Another important factor has also tended to produce a general elevation of the fetal perinatal mortality rate for 1931 to 1935. Fifty-three per cent of the patients admitted during this period were emergency cases, and many of them were in poor general condition. Indeed 16 of these babies were already dead and 2 of the mothers died from shock and infection shortly after admission. Presumably an appreciable number of the babies, although alive on admission, were not fit to stand more than the easiest of deliveries. I fe<'l sure this factor contributed to a general elevation of the fetal mortality during the period J 931 to 1985, but to what extent I am unable to asc<'rtain from the notes. 'l'he incidence of the ca~ws diagnosed at each level of cervical dilatation has remained remarkably constant during both 5 year periods and therefore this factor has had no influence 011 the changed perinatal mortality.
Comment It is apparent from what has lw0n said above that if the fetal perinatal survival rate is to be further increasetl, continuous vigilance must be exer·eised with the possibility of prolapse of the cord ever at the back of one's mind, and should the possibility materialize, then, in the main, only 2 lines of treatment should be followed: ( 1) immediate vaginal deliYery, provided the cervix is fully or almost fully dilated and delivery is expected to be easy; (2) immediate cesarean section if the cenix is incompletely dilated or vaginal delivery is expected to be difficult for any other reason, such as pelvic contraction. I would like to plead that the full equipment for a cesarean section should always be kept sterilized and ready for immediate use should such an emergency as prolapse of the cord arise. The cesarean section could, however, be performed in the labor ward if the operating theater were engaged. It is, of course, important to continue with the initial treatment while preparations are being made for the operation and to auscultate th(• fda] heart again immediately before the operation. The objection to further increasing the cesarean section rate lies in the dsk to the mother. Marshall and Cox 6 have shown that during the first 24 hours of Jabot· the maternal risk is less than 0.35 per cent, and it is within this time limit that all cases of prolapsed cord were diagnosed at Saint Mary's Hospitals during 1951 to 1955 (except for 2 cases in each of which the baby weighed less than 3 pounds). Most mothers would, I feel sure, gladly accept this small risk in order to obtain a living child. Obviously if the risk to the mother from cesarean section is markedly increased, or the fetus has a poor chance of survival, an alternative method of treatment should be adopted. provided this carries a lower maternal risk. The alternatiYe courses of action are: 1. Replacement of the cord, which carries a high fetal perinatal mortality, and its usefulness is thrrdore restricted to those cases in which the chance of fetal survival is already doubtful, as in the case of marked prematurity. :2. Vaginal aelivHy through the undilated cervix or after manual dilatation of the eervix, which is associated with a high perinatal mortality and the risk of serious damag·e to the mother. The place of this treatment in modern obstetrical practice can be taken more safely by cesarean section. :3. An expectant poliey is, of eourse, followed if the fetus is dead, or, very occasionally, in the treatable case when the maternal condition is so unsatisfactory (e.g., cardiac failure) that replacement of the cord under general anesthesia carries a maternal risk ont of proportion to the poor chance of fetal survival.
1242
NORBURN
Am. J. Obst. & Gynec. December. 1959
Summary An analysis is presented of 84 cases of prolapse of the cord occurring from 1951 to 1955 at Saint Mary's Hospitals, and these have later been compared with the 64 cases which occurred during 1931 to 1935. The incidence including the relationship to maternal age and parity has been considered. Malpresentation and prematurity were the most eommon etiological factors. The diagnosis has been discussed. It is doubted if spasm of the cord vessels plays such an important role in causing fetal death as has been suggested elsewhere. The corrected fetal perinatal mortality for 1951 to 1955 was 25 per cent. Presentation of the cord carries a similar fetal risk to prolapse of the cord. Certain important factors in relation to perinatal mortality have been considered. The treatment, both initial and active, has been discussed and conclusions drawn as to how further reductions may be made in fetal perinatal mortality. All the babies died when replaccmrnt of the cord was performed. Immediate vaginal delivery through the incompletely dilated cervix carried a perinatal mortality of 56 per cent together with a high maternal rnorbidity rate. It would appear that the fetal perinatal mortality may be further lowl't·ed by following 2 main lines of treatment, eithf'r immediate vaginal delivt>ry. if this is easy, or immediate cesarean seetion. All treatable cases, except in 2 markedly premature infants, of prolaps<· of the cord at Saint Mary's Hospitals from 1951 to 1955 occurred within the first 24 hours of labor, when the maternal risk from cesarean section is low. I wish to express my thanks to the chairman and members of the Medical Committe,-, of Saint Mary's Hospitals for permission to quote from the Hospital Records. l am also greatly indebted to Professor W. I. C. Morris for his invalnahle help and criticism throug-hout the preparation of this paper.
References 1. Stephens, J.: Lancet 2: 196, 1847. 2. Fenton, A. N., and D'Esopo, D. A.: AM. J. 0BST. & GYNEC. 62: 52, lfl.)J. 3. Bourgeois, G. A.: AM. J. 0BST. & GYNEC. 41: 837, 1941.
4. Rhodes, P.: Proc. Roy. Soc. Med. 49: 937, 1956. 5. Moir, J. Chasaar: Munro Kerr's Operative Oh,;tetrics, ed. 6, London, 1956. Baillien·. Tindall & Cox, p. 262. 6. Marshall, C. M., and Cox, L. W.: Tr. Brit. Cong. Obst. & G.vnaee_ 12: 30. 19:)<1.