In1 J Gynecol Obstet,

285

1992, 39: 285-289

international Federation of Gynecology and Obstetrics

A trial of labor after cesarean section in patients with or without a prior vaginal delivery C. Bedoya,

J.L. Bartha,

Division of Maternal-Fetal Seville (Spain)

I. Rodriguez,

Medicine. Departament

I. Fontan,

of Obstetrics

J.M. Bedoya and J. Sanchez-Ramos

and Gynecology,

Clinical Hospital

‘Virgen Maearena’,

University of

(Received March Sth, 1992) (Revised and accepted June 18tb, 1992)

Abstract OBJECTIVE: To determine the outcome of labor in women with a previous cesarean section, with or without prior vaginal delivery. METHOD: Records were reviewed for 1065 women with a previous cesarean section at ‘Virgen Macarena’ Hospital who were attended for a subsequent labor. RESULTS: Chisquared tests demonstrated that women with previous vaginal delivery (n = 346) had a significantly higher rate of vaginal delivery after a trial of labor (95.24O/9) than those without previous vaginal delivery (n = 719) (82.95%). All the ruptures of uterine scar (n = 4) were found in women without previous vaginal delivery. CONCLUSION: It appears that a cesarean section in a multiparous woman is not a determinant fact in her reproductive history and the risk of rupture of uterine scar did not appear to be present.

Keywords: Cesarean section; Trial of labor; Parity. Introduction Several years ago in Spain, a trial of vaginal delivery was recommended to women with a previous cesarean section. The outcome of this trial has been reported previously [l-4]. 0020-7292/92605.00 0 1992 International Federation of Gynecology and Obstetrics Printed and Published in Ireland

This trend is now being followed in many obstetrics centers. High rates of uterine scar dehiscence or uterine rupture have not been reported and this procedure has been deemed to be safe. Nevertheless, a rigourous selection of patients is required. Presently the success of this procedure reaches 81% in one series published [5]. Overall matemofetal outcome is very favorable and the indication of this procedure appears to be acceptable (Table 1) [5-131. Prior reports on previous cesarean section did not make a distinction between women without a previous vaginal delivery and women with one or more previous vaginal deliveries. We consider that a comparative study between both groups is suitable because previous vaginal delivery may play a role in the outcome of vaginal birth after cesarean section. Subjects and methods A group of 1065 patients with only one previous cesarean section attended our clinic between January 1985 and June 1991, which represents 4.58% of the deliveries during this period (n = 23276). From these patients, 719 (67.51%) were women without a previous vaginal delivery and 346 (32.49O/,) were women with one or more previous vaginal deliveries. Article

286

Bedoya et al.

Table 1. Characteristics of the previous studies about vaginal births after cesarean section. Year

Author

NUM

TL

VAG

%

DEH

PM

1987 1988 1988 1988 1989 1989 1989

Phelan Targett Muylder Flamm Chua Roumen Meehan

2708 4892 400 4929 305 249 2434

1796 1577 288 1776 207 192 1350

1465 1197 235 1314

81 75.9 82 74 69 60.6 81.2

1.9 0.8 0.7 0 1.4 0.5 -

0.13 -

1989 1990 1991

Meehan Egwuatu Pm. Rep.

1498 154 1065

844 102 687

83 71 88.3

0.6 4.9 0.38

151

73 606

1 0.6 2 1.41

NUM, total number of cases; TL, trial of labor; VAG, total number of vaginal births; DEH, dehiscences of the uterine scar; PM, perinatal mortality; Pre. Rep., present report.

Our clinical protocol of these women did not include vaginal delivery in those with breech presentation, multiple pregnancy or pelvic narrowness diagnosed by X-raypelvimetry. We routinely used X-raypelvimetry during labor, with all patients who had a previous cesarean section. When there IS a cephalopelvic disproportion, the trial of labor is not allowed [14]. Oxytocins are used with primiparous women by continuous perfusion of 5 IU oxytocin diluted in 500 ml a

6

glucosaline, with a variable rate according to the dynamic response. A solution of 2.5 g of thiopental sodium in 500 ml glucosaline is administered intravenously, discontinously according to the response, looking for twilight sleep. This begins in the active phase of labor and ends after the delivery when the manual revision of the uterine cavity is done to search for the possible rupture of the uterine scar

WI. A comparative

study is made

%

__

. . ,,,,,,,,..,..._.._.......,....,......

4-

2 x I

10sas

I

1

1987

1986 -

total

+

“‘~“““‘.~~~~~‘...........,...,, ,.,,,,,,,,,,. ., ,,, x

;k

I

I

I

1988

1989

1990

without PVD

FVD:previous vaginal

-+k

I 1991

with PM

delivery

Fig. 1. Percentage of women with previous cesarean section followed in our clinic during the time of the study. I~I J Gynecol Obstet 39

between

281

Vaginal birth after cesarean section

women with or without a previous vaginal delivery regarding the rate of trial of labor and the rate of vaginal delivery following this trial of labor. The incidences of ruptures of uterine scar and perinatal mortality in each group were also studied. Statistical analysis was performed using the $-test. Statistical significance was set at the 0.01 level.

Table 2. Number of ruptures of uterine scar in patients with previous cesarean section (n = 1065).

With PVD Without PVD Total

Without TL DEH

With TL

DEH

52 326 378

294 393 687

0 3 3

0 1 1

DEH, dehiscences of the uterine scar; TL, trial of labor; PVD, previous vaginal delivery.

Results Figure 1 shows the total number of cases following a previous cesarean section in our clinic during the years of the study. The trend is rising for women without a previous vaginal delivery and is decreasing for women with a prior vaginal delivery. Afterwards the total number of patients in labor with a previous cesarean section increased in our clinic. Figure 2 shows that the rate of vaginal delivery descends until 1988. This tendency is then reversed and reaches similar rates up to 1985 at the end of the study.

20

Table 1 shows the comparison between our dates on rates of vaginal delivery, trial of labor, vaginal delivery following trial of labor, rupture of the uterine scar and perinatal mortality and those reported in the literature. The rate of vaginal delivery following trial of labor (606/687) (87.0S”/, was the highest. The percentage of dehiscences and perinatal mortality was similar to those reported by other authors. Table 2 shows the differences between both groups of patients related to uterine

_,

I

-

1

I

1os85 1986

1987 TOTAL

+

1988 WITHOUT PVD

PVD: previous Fig. 2.

1

1989

I

1990

1991

*... WITH PVD

va@nal delivery

Rate of vaginal delivery in women with a previous cesarean section followed in our clinic during the time of the study. Article

288

Bedoya et al.

Table 3.

Intrapartum and postpartum mortality in patients with a previous cesarean section.

With PVD Without PVD Total

Without TL IP

PP

With TL IP

PP

52 326 378

0

294 393 687

0

0 0 0

1 1

1

0 3 3

1

TL, trial of labor; IP, intrapartum mortality; PP, postpartum mortality; PVD, previous vaginal delivery.

dehiscence. All cases of dehiscence of uterine scar happened in women without a previous vaginal delivery. Three of them proceeded during a trial of labor stimulated with oxytotin and ended with cesarean section for failure of progression. The 3 newborns progressed normally. All cases of dehiscence of uterine scar happened in women without a previous vaginal delivery. Three of them proceeded during a trial of labor stimulated with oxytocin and they ended in cesarean section for failure of progression. The 4 newborns were healthy. Overall mortality was 1.41% (1511065). Two were neonatal deaths, one had a respiratory distress syndrome associated with low weight and the other was an hydrocephalus. Of the 3 intrapartum deaths, 2 were acute fetal distress and the other was a chronic fetal distress who arrived in advanced stage of labor. The 3 were extracted by forceps in the pelvic floor (Table 3). A comparison between both groups with respect to the number of trials of labor and

Table 4. Number of trials of labor and rate of vaginal delivery in patients with a previous cesarean section.

NUM Total 1065 Second 719 Multiple 346

TL 687 393 294

% 64.51 54.66* 84.97

VAG TL

%

606 326 280

88.3 82.95* 95.24

* P < o.ooo1. NUM, total number of cases; TL, trial of labor; VAG TL, number of vaginal births after trial of labor. Int J Gynecol Obstet 39

the rate of vaginal delivery following, is shown in Table 4. The number of trials of labor (84.97% vs. 54.66%) as well as the percentage of vaginal births after that (95.24% vs. 82.95%) were higher in women with a prior vaginal delivery (P < 0.0001). Discussion The rate of cesarean section has increased continually in the United States over the last years, reaching 24.4% of total deliveries in 1988 [ 16,171. A similar trend is followed in Spain. Not surprisingly, the number of patients with previous cesarean section followed up in obstetrics centers is rising also. Our clinic is not an exception, as is depicted in Fig. 1. Nevertheless, this is not true for women with a prior vaginal delivery. One possible explanation is the overall fall in the parity of Spanish women. From 1985 to 1988 the use of oxytocin for augmentation of labor was restricted in these women. Consequently, the rate of vaginal delivery fell. After that, a new liberal strategy was implemented. It resulted in a rise of vaginal delivery reaching percentages similar to those in 1985 (Fig. 2). Overall, the high rate of vaginal delivery after trial of labor, the low incidence of dehiscences, the lack of association between perinatal mortality and the existence of previous uterine scar support the use of this procedure. Our low rate of dehiscences after trial of labor in comparison with other authors [5-10,12,13] can be explained by a restrictive protocol that did not allow trial of labor to women with twin pregnancy, breech presentation, pelvic narrowness diagnosed by X-raypelvimetry and two or more previous cesarean sections. Pruet et al. [18] found that the technique of double layer suture after hysterotomy prevents dehiscences. Accordingly, we have used this technique with positive results. The fact that all dehiscences always happened in women without a previous vaginal delivery and never in women with a prior

Vaginal birth after cesarean section

vaginal delivery might imply that if there is not a uterine rupture it will not take place in subsequent deliveries. Nevertheless, this difference was not statistically significant. All the ruptures of uterine scar were found during a new cesarean section. These were done after arrested labor, without other signs and without fetal distress. In the 3 cases a uterine suture was done. The ultrasonography study of uterine scar during pregnancy does not appear necessary due to the low incidence of dehiscences [19,20]. The incidence of previous vaginal delivery was followed by a higher rate of vaginal delivery. This rate is similar to the one in women with a prior vaginal delivery without previous cesarean section. This fact, the null intrapartum mortality and the null dehiscences of the uterine scar probably mean that a cesarean section in women with previous vaginal delivery is not a determinant fact in her reproductive history. Further analysis about the importance of causes and the stage of labor in cesarean section on the success of subsequent births is required to separate both groups of women.

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9

10

11

12

13

14

15 16

17

References 18 Bedoya JM, Navano J: El parto vaginal despues de ceszlrea. Toko-Gin P&t 24: 847, 1965. Turiel de Castro D, Garcia Torres J, Morante del Blanc0 MJ: Conducta ante una cesarea anterior. Toko-Gin Pratt 29: 46, 1970. Sisniega CL, Duyos JA: Estudio estadistico del parto vaginal postcesarea anterior. Toko-Gin PrCt 34: 171, 1975. Chinchilla Calvo C: La cicatriz uterina en la ceslrea. Evaluacibn de las pacientes en gestaciones ulteriores. Acta Gin 24: 703, 1975. Phelan JP, Clark SL, Diaz F, Paul RH: Vaginal birth after cesarean. Am J Obstet Gynecol 157: 1510, 1987. Targett C: Caesarian section and trial of the scar. Aust N 2 J Obstet Gynecol 28 (4): 249, 1988. De Muylder X: Vaginal delivery after caesarean section:

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is it safe in a developing country? Aust N Z J Obstet Gynaecol28 (2): 99, 1988. Flamm BL, Lim OW, Jones C, Fallon D, Newman LA, Mantis J K: Vaginal birth after cesarean section: results of a multicenter study. Am J Obstet Gynecol 158 (5): 1079, 1988. Chua S, Arulkumaran S, Singh P, Ratnam SS: Trial of labour after previous caesarean section: obstetrics outcome. Aust N Z J Obstet Gynaecol29 (I): 12, 1989. Roumen FJ, Janssen AA, Vrouenraets FP: Het verloop van baring na voorafgaande keizersnede. Ned Tijdschr Geneeskd 133 (13): 672, 1989. Meehan FP, Magani IM: True rupture of the caesarian section scar (a 15-year review, 1972-1987). Eur J Obstet Gynecol Reprod Biol 30 (3): 129, 1989. Meehan FP, Burke G, Casey C, Sheil JG: Delivery following cesarean section and perinatal mortality. Am J Perinatol 6 (I): 90, 1989. Egwuatu VE, Ezeh IO: Vaginal delivery in Nigerian women after previous cesarean section. Int J Gynaecol Obstet 32 (I): 1, 1990. Bedoya JM. Radiologia obstetrica. ‘En Labor en la Matemidad de la Macarena’. Edit. Universidad de Sevilla, Vol. 3, p 1, 1963. Bedoya JM: El ‘m&do sevillano’ de analgesia en el parto. Progresos de Obstetricia y Ginecologia 8: 8, 1965. Amirikia H, Zarewych B, Evans TN: Cesarean section: A 15-year review of changing incidence, indications and risks. Am J Obstet Gynecol 140: 81, 1981. TatTel SM, Placek PI: An overview of recent patterns in cesarean delivery and where we stand today. In: Proceedings of the one hundred sixteenth annual meeting of the American Public Health Association, Boston, Massachusetts, November 15, 1988. American Public Health Association, Boston, 1988. Pruett KM, Rinshon B and Cotton BB: Unknown uterine scar and trial of labor. Am J Obstet Gynecol JJ7: 807, 1988. Michaels WI-I, Thompson HO, Boutt A, Schreiber FR, Michaels SL, Rare J: Ultrasound diagnosis of defects in the scarred lower uterine segment during pregnancy. Obstet Gynecol 71: 112, 1988. Lonky NM, Worthen N, Ross MG: Prediction of cesarean section scars with ultrasound imaging during pregnancy. J Ultrasound Med 8: 15, 1989.

Addrez3s for reprints: c. Bedoya Belgua Avda. Bhs Infante, lI, A 41011, SevBk?, Spain

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