In the last decade, several large studies1–3 have challenged the safety and appropriateness of a trial of labor after cesarean delivery. According to these reports, there is an increased maternal and perinatal morbidity associated with a trial of labor after cesarean delivery compared with a planned repeat cesarean delivery. These studies had a major impact, as evidenced by a dramatic decline in the rate of vaginal birth after cesarean (VBAC) and concomitant increase in the rate of cesarean deliveries in the United States and elsewhere, a trend that exists also in Israel. Although, in the developed Western world, many women have only one or two children, there are many countries and communities in which larger families are common. Implementation of the aforementioned trend in such populations will obviously lead to an increase in the number of women having multiple cesarean deliveries. Because the data from the above-mentioned studies relate only to a single repeat cesarean delivery and may not be applicable to multiple cesarean deliveries, their conclusions may not be relevant to women who desire larger families. Undoubtedly, data regarding maternal morbidity associated with multiple cesarean deliveries are of utmost importance for counseling such women before they decide whether to undertake a trial of labor after one cesarean delivery or undergo a planned repeat cesarean delivery that will consequently lead to multiple cesarean deliveries. To date there is only a limited number of studies that specifically addressed maternal complications associated with multiple cesarean deliveries, and their results are conflicting. Our MEDLINE search for publications in English between January 1, 1980, and April 1, 2005, using the key words “repeat cesarean delivery” and “multiple cesarean deliveries,” yielded only eight relevant studies.4–11 The aim of the present study was to assess maternal complications associated with three or more repeat cesarean deliveries compared with a second planned repeat cesarean delivery.
MATERIALS AND METHODS
We performed a retrospective cohort study from January 2000 through May 2005 in our institution. The Bnai-Zion Medical Center is a level 3 university hospital that mainly serves the urban population of the city of Haifa, Israel. The annual number of deliveries is approximately 4,500, and the cesarean delivery rate during the study period gradually increased from 17.2% in the year 2000 to 20.8% in 2005. In our system, the deliveries are conducted by certified midwives supervised by residents, staff obstetricians, and maternal–fetal medicine specialists.
The medical records of all women who underwent two or more planned cesarean deliveries during the study period were reviewed. We compared maternal complications between women who underwent three or more planned cesarean deliveries (multiple-cesarean group) and women who had a second planned repeat cesarean delivery (second-cesarean group). Women undergoing cesarean delivery after failed VBAC were excluded. Women scheduled for planned cesarean delivery presenting in labor were classified as in labor cesarean delivery. The study was approved by the institutional review board of the Bnai Zion Medical Center, Technion, Israel Institute of Technology, Haifa, Israel.
Our policy is to encourage all women with a prior, single, low-segment cesarean delivery and a singleton cephalic gestation to undergo a trial of labor, unless repeat cesarean delivery is indicated. Breech presentation, multiple gestations, estimated fetal weight of more than 4,000 g (by clinical and ultrasonic estimation), unknown uterine scar, low vertical incision, inverted T incision, or any other uterine scar, as well as patient’s request, are considered indications for repeat planned cesarean delivery. All parturients with a history of two or more cesarean deliveries are booked for a planned cesarean delivery. We usually schedule a second cesarean delivery between 38.0 and 39.5 weeks, whereas women with two or more previous cesarean deliveries are scheduled for surgery slightly before or at 38 weeks. This policy is intended to decrease the risk of uterine rupture, associated with spontaneous labor in women with multiple uterine scars. Gestational age is either confirmed or recalculated based on an early ultrasound biometry. Operations in our department are performed either by residents supervised by staff obstetricians or by the staff obstetricians themselves. We usually use a Pfannenstiel incision to enter the abdominal cavity and a transverse incision in the lower segment of the uterus. The uterine incision is closed by a single layer of #1 Vicryl (Ethicon Inc, Somerville, NJ) interlocking suture. The visceral and parietal peritoneum are left open. A single dose of a second-generation cephalosporin is administered intravenously after cord clamping. We provide postpartum thrombophylaxis only to women who are at increased risk for thromboembolism. During the study period our surgical techniques, type of sutures, and postoperative management remained unchanged.
The medical records for all eligible women were reviewed by one of the authors (V.N.). Demographic data, details of medical and obstetric history, and information on the intraoperative and postoperative events were recorded. In particular, from the surgery report we obtained data on estimated blood loss, blood transfusion, abdominal adhesions, extension of the uterine incision, dehiscence of uterine scar, uterine rupture, incidence of cesarean hysterectomy, placenta previa, bladder and bowel injury, and difficulties in the delivery of the neonate. From the postoperative records, we obtained data on postoperative morbidity, including febrile morbidity, skin wound complications, the need for relaparotomy, thromboembolic events, and length of hospital stay. The intra- and postoperative complications were categorized as either major or minor complications. Indeed, this classification is arbitrary, yet it represents the magnitude of the complication, and most importantly, the criteria for the classification were established a priori. Late postoperative morbidity, after discharge, was not included in this study.
Uterine rupture was defined as a disruption or tear of the uterine muscle and visceral peritoneum. Uterine dehiscence was defined as a disruption of the uterine muscle with an intact serosa. A difficult delivery was defined as such if there were problems concerning neonatal extraction through the uterine incision, as mentioned in the surgery report, mainly due to a scarred abdominal wall. Excessive blood loss was defined as blood loss of 1,000 mL or more or transfusion of two or more units of blood as an indirect representation of excessive blood loss during surgery. Dense adhesions were defined as the presence of multiple adhesions between the uterus and surrounding tissues or organs. Postpartum febrile morbidity was defined as a temperature of 38.0°C (100.4°F) or higher on any two of the first days after delivery, exclusive of the first 24 hours. Major maternal complication was defined as the occurrence of one or more of the following: uterine rupture, hysterectomy, relaparotomy, operative injury (bladder, bowel), thromboembolism, and excessive blood loss. Minor maternal complication was defined as the occurrence of one or more of the following: extension of uterine incision to the cervix or to the broad ligament, postpartum febrile morbidity, wound infection, uterine scar dehiscence, transfusion of one unit of blood, and difficult delivery of the newborn. The presence of dense adhesions was recorded and analyzed separately.
Demographic variables, clinical features, and complications were compared between the multiple cesarean group and the second cesarean group with Student t test, Mann-Whitney test, and Pearson χ2 test, as appropriate, for continuous, ordinal, and categorical variables, respectively. Fisher exact test was used when appropriate. Trend in probability of complications associated with increasing number of cesarean deliveries was tested with χ2 test for trend.12
Multivariable logistic regression was used to estimate adjusted odds ratio (OR) and 95% confidence interval (CI). The model included important clinical variables: maternal age, parity (more or less than 4), and gestational age (more or less than 37 weeks). Index cesarean variable was entered as a covariate (one degree of freedom) to estimate adjusted P value for trend. Significance tests were two-sided and P < .05 was considered significant. Statistical analysis was performed with SPSS 11.5 (SPSS Inc, Chicago, IL).
Altogether, 940 repeat cesarean deliveries were performed during the study period, 172 of which were undertaken because of failed trial of labor, and were thus excluded. Of the remaining 768 women, 491 women underwent two cesarean deliveries and 277 women underwent three or more; of these women, 213 underwent three cesarean deliveries, 56 had four, 7 had five, and 1 had seven cesarean deliveries.
Demographic and obstetric characteristics of the two groups are presented in Table 1. As could be expected, maternal age and parity were higher and gestational age was lower in the multiple-cesarean group. Twin pregnancies and pregnancy-induced hypertensive disorders were more common in the second-cesarean group. The groups were otherwise similar with respect to other pregnancy complications, the proportion of women who underwent in labor cesarean delivery, and the type of anesthesia. The incidence of chronic illness such as asthma (3.6% versus 3.5%), diabetes mellitus (0.7% versus 1.2%), chronic hypertension (3.6% versus 2%), connective tissue diseases (0.4% versus 0.2%), and neurological (0.7% versus 1%) and endocrine disorders (2.2% versus 2.6%) was comparable in the two groups (multiple-cesarean and second-cesarean group, respectively).
Intraoperative complications are presented in Table 2. Excessive blood loss (7.9% versus 3.3%; P < .005), difficult delivery of the neonate (5.1% versus 0.2%; P < .001), and dense adhesions (46.1% versus 25.6%; P < .001), were significantly more common among women in the multiple-cesarean group. Regarding dense adhesions and excessive blood loss, adjusting for maternal age, parity, and gestational age, the differences between the groups remained statistically significant (P < .001, OR 2.5, 95% CI 1.8–3.4; and P = .018, OR 2.3, 95% CI 1.1–4.5, respectively) (Table 2). Three women (1.1%) in the multiple-cesarean group required hysterectomy (two placenta accreta, one uterine atony) compared with only one woman (0.2%) in the second-cesarean group (placenta accreta). Bladder (two cases) and bowel injury (one case) occurred only in the second-cesarean group, but these differences in specific rare major morbidities between the groups were not statistically significant. Three women in the second-cesarean group (0.6%) had placenta accreta, compared with four women in the multiple-cesarean group (1.4%, P = .26). Three of the four cases of placenta accreta among the multiple-cesarean group occurred among women with four or more cesarean deliveries (3/64 [4.7%] compared with 3/491 [0.6%] for women with four or more cesareans and women with two cesareans, respectively, P = .023).
Minor and major postoperative complications were not significantly different between the two groups. The incidence of abdominal scar problems, including wound infection or hematoma drainage, was 4/277 (1.4%) in the multiple-cesarean group and 3/491 (0.6%) in the second-cesarean group (P = .26). The percentage of postpartum febrile morbidity was similar in the two groups (2.9%). Relaparotomy because of intra-abdominal hemorrhage was performed in 3/277 patients (1.1%) in the multiple-cesarean group and in 2/491 (0.4%) in the second-cesarean group (P = .357). Pulmonary embolism occurred in one patient from the multiple-cesarean group (0.4%) and was not reported among women in the second-cesarean group (P = .361). The length of postoperative hospitalization was similar between the two groups (median 4.0, range 2–27 days in the multiple-cesarean group and median 4, range 2–25 days, in the second-cesarean group). When data were stratified according to the mode of cesarean (planned or in labor), the results were similar (data not shown).
Because some women may have more than one complication, we examined what proportion of women in each of the study groups had one or more complications. For this purpose, we used two composite outcomes: “any major complication” for women with at least one major complication with or without minor complications, and “any minor complication” for women with at least one minor complication. The proportion of women having any major complications (intraoperative or postoperative) was significantly higher in the multiple-cesarean group compared with the second-cesarean group, 8.7% versus 4.3%, respectively (P = .013) (Table 3). The risk of having any major complication increased with cesarean delivery index number: 4.3%, 7.5%, and 12.5% for second, third, and fourth or more cesarean delivery, respectively (P for trend = .004) (Table 4). These differences remained significant also after controlling for maternal age, parity, and gestational age (Table 3 and Table 4).
Large families are common in many countries and communities throughout the world. As the rate of primary cesarean deliveries increases and the rate of VBAC decreases, the number of women who will consequently undergo multiple cesarean deliveries will eventually increase.
Our results demonstrate that, compared with a second cesarean delivery, multiple cesarean deliveries are associated with more surgical difficulties and a slight, but statistically significant, increase in major complications. Dense adhesions, which have been also reported by other investigators,4,7,8,10 not only create difficulties for the surgeon but may also pose an increased risk to the patient by prolonging operation time and by increasing the risk of injury to adjacent organs. Indeed, the three cases of such an injury among our patients were associated with dense adhesions. Similar to our results, two previous studies4,5 reported an increased risk of major operative complications and abnormal placentation in women with multiple cesarean deliveries. Makoha et al5 in Saudi Arabia studied maternal complications among women who have undergone between one and eight cesarean deliveries. The authors concluded that maternal morbidity increased with successive cesarean delivery before and through the third cesarean delivery. However, compared with the third, the risk of major morbidity was significantly increased with the fifth and was much worse at the sixth cesarean delivery for placenta previa, placenta accreta, and hysterectomy. Abnormal placentation, which was associated with three of the four hysterectomies in our study, seems to be the leading cause of major complications in women with multiple cesarean deliveries. As reported by others,4–6,13,14 we observed the highest proportion of placenta accreta among the group with four or more cesarean deliveries. In contrast, several other authors6–11 deny that multiple cesarean deliveries carry an increased risk for surgical or postoperative complications. Rashid et al10 in Saudi Arabia compared maternal complications between 308 women with five or more cesarean deliveries and 306 women with three or four cesarean deliveries. The authors concluded that the high number (5–9) of repeat cesarean deliveries carries no specific additional risk for the mother or the newborn when compared with the lower number (3 or 4) cesarean deliveries. Regarding postoperative complications, our data, as well as most of the above-mentioned studies, demonstrate a relatively low rate of complications and a lack of a significant correlation with the number of previous cesarean deliveries.
We acknowledge some limitations to our study. 1) Due to the retrospective nature of the study, we cannot rule out that some complications were not fully documented. In an effort to minimize this shortcoming, we reviewed, not only the computerized records, but also each patient’s chart, including handwritten data. 2) Likewise, data regarding adhesions, difficult delivery, and blood loss cannot be quantified retrospectively and are based on subjective description of the surgeons. 3) Even with the fairly large cohort, the number of women who underwent three or more cesarean deliveries is relatively small. Moreover, because of the rareness of major complications such as hysterectomy, bladder, or bowel injury, our study did not have the power to detect differences for any specific major complication between the groups, even if they existed. In conclusion, with the growing rate of cesarean deliveries worldwide, women should be counseled that approximately 9% of those undergoing multiple cesarean deliveries may suffer from major complications, and approximately 1% will require hysterectomy, most commonly as a result of abnormal placentation.
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© 2006 by The American College of Obstetricians and Gynecologists. Published by Wolters Kluwer Health, Inc. All rights reserved.
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