Reserves for reducing the frequency of cesarean section in a level 3A hospital

Introduction

Cesarean section (CS) is one of the most common surgeries in the world, the incidence of which has remained consistently high over the past decades. In 1985, a group of experts convened by the World Health Organization (WHO) concluded: “There is no justification for the CS rate to be higher than 10–15% in any region” [1]. In 1990, the CS rate worldwide was 6.7% [2]. According to a retrospective analysis of data from 150 countries for the period of 1990–2014, covering 96.1% of live births worldwide, the proportion of abdominal births increased to 18.6% [2], and by 2018, their incidence reached 21.1% [3]. The prognosis for the growth of the CS rate is extremely disappointing; at the current rate, in 2030, 28.5% of women worldwide will give birth by CS (38 million CS operations annually). This data will vary from 7.1% in sub-Saharan Africa to 63.4% in East Asia [3]. In Russia, the dynamics of the CS rate are comparable with global trends since it was 22.3% in 2010 and increased to 31.2% by 2022¹.

In 2015, WHO published the following guidelines regarding the level of operative delivery worldwide:

1. CS is effective in saving the lives of mothers and babies, but only when it is medically necessary.
2. At the population level, a CS rate exceeding 10% is not associated with a reduction in maternal and perinatal mortality.
3. CS may result in serious (and sometimes irreversible) complications, disability, or death, especially in the absence of conditions and/or opportunities to properly perform safe surgery and treat surgical complications. Ideally, CS should be performed only when it is medically necessary.
4. Every effort should be made to ensure that CS is provided only to women in need, rather than aiming at a specific target.
5. The impact of the CS rate on other outcomes such as maternal and perinatal morbidity, pediatric outcomes, and psychological or social well-being remains unclear. Further studies are needed to evaluate the impact of CS on short- and long-term outcomes².

For the assessment, monitoring, and comparison of СS indicators, WHO and the International Federation of Gynecology and Obstetrics recommend the Robson classification (RC)² [4][5].

In the Russian Federation, the use of the RC is regulated by the letter of the Ministry of Health of Russia dated February 22, 2022 No. 15-4/I/2-2832 “Recommendations for the implementation, using and analysis of the report on the Robson classification of the cesarean section operation”. The RC is represented by 10 mutually exclusive and fully inclusive groups, which allow classifying all women admitted to childbirth.

Some studies use a modified Robson scale. In particular, in the original paper “A step towards better audit: Robson’s 10-group classification system for outcomes other than Caesarean section”, the RC with subgroups was used to analyze the CS rate since 2002 [6].

Medical indications for abdominal delivery have expanded significantly over the past 20 years; moreover, CS at the request of a woman without medical indications has become a global trend [7][8][9].

Thus, the persistent high frequency of CS and associated complications in pregnant women with an operated uterus, as well as the ambiguity of conclusions about the reserves for its reduction, remain a significant problem of global health care at the end of the first quarter of the 21st century. The question of whether the frequency of CS is a controllable factor remains debatable.

According to WHO recommendations, interpretation of the CS report can provide useful information on the quality of data collection, as well as the type of population served by the maternity care facility, the CS rates in each group, and how each patient of the 10 groups contributes to the overall CS rate in the facility³. The WHO data for comparing the above indicators are based on two sources: international experience of CS since 1990 [5][10][11] and the WHO Multi-Country Survey on Maternal and Newborn Health [12][13]. The latter study was conducted in 370 medical institutions in 29 countries, involving more than 275,000 women in Africa, Asia, the Eastern Mediterranean region, and Latin America between May 1, 2010 and December 31, 2011 [14]. Based on these investigations, a so-called “reference population” was presented, which included patients from all facilities with low CS rates and low perinatal mortality. It was assumed that in these institutions, the number of operations performed in the absence of indications was negligible, and maternal and perinatal outcomes were favorable. Among these institutions, the 50th percentile of the CS rate was 30% and the 50th percentile of the perinatal mortality rate was 6.8 per 1000 live births.

WHO regulates three steps for analyzing a report³:

1. Data quality assessment,
2. Definition of the obstetric population type,
3. Estimation of the incidence of CS.

The aim of the study was to substantiate the reserves for reducing the CS rate in a level 3A hospital via a retrospective analysis of patients who gave birth using the Robson classification.

Materials and methods

A retrospective analysis was based on 3771 birth histories of patients who gave birth in 2017 at the State Budgetary Institution of the Rostov Region “Perinatal Center”. The patients were divided into 10 groups according to the Robson classification. The accumulation and systematization of information, as well as visualization of the obtained results, were carried out in Microsoft Office Excel 2019 spreadsheets. Statistical analysis was performed using IBM SPSS Statistics 28.0.1.1 (developer IBM Corporation), STATISTICA 13.5.0.17 (developer StatSoft.Inc), and the MedCalc 20.027 package.

Results

In accordance with WHO recommendations³, we analyzed the indicators of the standardized form “Robson Classification Report Table” (Table 1), the assessment of data quality (Table 2), and the assessment of the population type (Table 3).

An analysis of delivery methods showed that out of 3771 deliveries, 2018 women were delivered abdominally, which amounted to 53.2% of the total number of births in 2017. The perinatal mortality rate, which often reflects the efficacy of CS, was 4.9%.

The proportion of group IX, involving all women with a singleton pregnancy, transverse or oblique fetal position, including women with one or more CS in the anamnesis, was 1.2% in the studied cohort of patients, which was slightly higher than the indicator according to both Robson recommendations and WHO data (Table 2). This probably indicates the concentration of patients classified in this group in a level 3A hospital and not a low level of data collection quality.

The combined proportion of primiparous patients with one fetus in cephalic presentation, ≥ 37 weeks, spontaneous onset of labor, induction of labor, or CS before the onset of labor (groups I+II according to the RC) was 30.2%, which was lower than the same indicator in both Robson’s interpretation and the “WHO Reference Population” (Table 3). The proportion of multiparous patients without a previous CS with one fetus in cephalic presentation, ≥ 37 weeks, spontaneous onset of labor, induction of labor, or CS before the onset of labor (groups III+IV according to the RC) was also lower and amounted to 25.2% (Table 3).

The proportion of multiparous patients with one or more CS in the anamnesis, one fetus in cephalic presentation, ≥ 37 weeks (group V according to the RC) was 16.4% and exceeded the indicator recommended by Robson by 1.6 times, as well as the indicator according to the “WHO Reference Population” by 2.3 times (Table 3). The proportion of all primi- and multiparous women with one fetus in breech presentation, including women with one or more CS in the anamnesis (groups VI + VII according to the RC), amounted to 6.8% and was also 1.7 times higher than the indicator recommended by Robson and 2.5 times higher than the value of the “WHO Reference Population” (Table 3). The most pronounced differences were obtained in the comparative analysis of groups VIII (7%), and X (13.2%). The proportion of women in labor with multiple pregnancies, including women with one or more CS in the anamnesis (group VIII according to the RC) and with singleton pregnancies, cephalic presentation, <37 weeks, including women with one or more CS in the anamnesis (group X according to the RC) was more than 3.5 times higher relative to the recommended levels.

The ratio of the number in groups I and II (2.5:1), III and IV according to the RC (6:1) did not have significant differences compared to the indicators recommended by Robson and WHO. The ratio of primiparous women with a singleton pregnancy in breech presentation to multiparous women with a history of CS (groups VI and VII) was 0.9, which was comparable to the level of the “WHO Reference Population” (0.8), but significantly differed from that recommended by Robson (2:1) (Table 3).

The obtained results on the size of I+II groups, which amounted to 30.2%, i.e. less than 30–35%, typical for most obstetric hospitals, demonstrated the predominance of multiparous patients who gave birth in 2017 in the level 3A obstetric institution studied. The size of III+IV groups (25.2%), which turned out to be lower than the traditional level (30–40%), was the result of the high proportion of hospitalized women in labor in group V (16.4%), i.e. patients who had previously given birth by CS. The sizes of groups VI+VII (6.8%), VIII (7%), and X (13.2%), significantly different from the reference population, indicated the correct routing of patients with high perinatal and obstetric risk to the level 3A hospital studied.

The ratio of the numbers of groups I and II according to the RC (2.5:1), groups III and IV (6:1) is primarily an indicator of the high quality of data collection and also demonstrates the predominance of patients with the spontaneous onset of labor over patients with induced labor and those delivered before the onset of labor. The ratio of groups VI (all primiparous women with a singleton pregnancy in breech presentation) and VII (all multiparous women with one fetus in breech presentation, including women with one or more CS in their anamnesis), detected as 0.9:1, attests to a predominance of multiparous women with breech presentation among the analyzed cohort.

Thus, the conducted analysis showed a predominance of patients belonging to a high perinatal and obstetric risk group in the examined population, which is probably one of the reasons for the high frequency of CS in this level 3A maternity hospital (53.2%).

The assessment of the CS indicators in each of the RC groups revealed the findings presented in Table 4.

Due to the fact that the rate of CS in each of the RC groups exceeded that recommended by Robson and WHO (Table 4), an analysis of the indications for CS in each group was conducted to identify true reserve groups for reducing the overall level of abdominal delivery in the institution under study.

In the clinical guidelines (treatment protocol) of the Ministry of Health of the Russian Federation “Cesarean section. Indications, methods of pain relief, surgical technique, antibiotic prophylaxis, postoperative management” dated May 6, 2014, No. 15-4/10/2-3190, indications for operative delivery are presented in 15 groups⁴.

Considering that a number of patients had indications that did not belong to any of these groups, within the framework of this analysis we identified group 16 with the name “other indications”, which included women who gave birth due to developing anomalies of labor, as well as those who had a combination of relative indications for operative delivery, and chorioamnionitis (Table 5).

The obtained data demonstrate that the leading reserve for reducing the frequency of operative delivery was associated with patients from groups I–IV according to the RC. In particular, 813 patients were classified in group I according to the RC, of which 191 (23.5%) were delivered surgically (Table 6). One of the main indications for delivery in group I was fetopelvic disproportions, which was revealed in 64 (33.6%) patients. Besides, 56 (87.5%) patients were operated due to the phenomena of the clinically narrow pelvis that developed during labor, and 8 (12.5%) were operated due to the development of labor activity and anatomical narrowing of the pelvis of degrees II–III. Other indications for CS in 54 (28.3%) patients were related to abnormalities in the development of labor that could not be corrected including primary and secondary weakness of labor and discoordinated labor. Of the 47 patients (24.6%) who delivered due to distress, in 41 cases (87.2%), the clinical picture was accompanied by the release of meconium into the amniotic fluid; in 3 patients from this group, newborns were born with an Apgar score of less than 7 points at 1 minute.

Group II according to the RC included 324 patients, of whom 291 (89.8%) women delivered surgically. The total number of women in labor with induced labor (Group IIa of the RC) was 70 (21.6%), of whom 37 (52.8%) patients delivered surgically. The main indications for delivery in Group IIa were developed abnormalities of labor (in 20 (54.1%) patients) and fetopelvic disproportions (in 10 (27%) women). The high frequency of CS in group II according to the CR was associated with the number of women from group IIb, more specifically 254 (78.3%) patients. In particular, 67 (26.4%) patients in this group were delivered for a combination of obstetric indications, as being referred to the “high” perinatal risk group, who did not have absolute indications for operative delivery either from the mother or the fetus. In 33 (13%) patients from this group, the indication for abdominal delivery was anatomical obstacles to vaginal delivery, among which 12 (36.3%) patients were diagnosed with cicatricial deformities of the cervix. In 35 (13.8%) cases, CS was performed before the development of regular labor due to the presence of anatomical narrowing of the pelvis.

Group III according to the RC included 815 women, of whom 38 (4.7%) patients were delivered by CS. The main indications for delivery in this group were fetopelvic disproportions (9–23.7%) and other indications, namely, developed anomalies of labor (8–21%).

The number of patients in group IV for CS amounted to 135, of whom 93 (68.9%) women delivered abdominally (Table 6). Group IVa was represented by 48 (35.5%) patients, of whom 6 (8.3%) women underwent CS; group IVb consisted of 87 (64.4%) patients, which determined the high level of CS in group IV as a whole. The leading indications for operative delivery in group IVb were anatomical obstacles to vaginal delivery (22 (25.3%) women), placenta previa (19 (21.8%) patients), and other indications (patients classified as high obstetric and perinatal risk groups without absolute indications for CS) involving 14 (16.1%) patients.

The obtained results indicate that one of the leading indications for operative delivery in groups I and III was pelvic-cephalic disproportion. In order to reduce the frequency of operative delivery for this group of patients, it is reasonable to consider the use of an alternative solution in the form of preinduction and induction of labor at full-term gestation. A significant “contribution” to the overall frequency of CS is made by patients who delivered with a combination of indications (after ART, complicated obstetric-gynecological and somatic history). This group of patients is also a reserve for reducing the frequency of CS. In fact, in this case, CS was performed both at the patient’s request and with regard to the doctor’s position (risk of lawsuits in the case of an unfavorable maternal and perinatal outcome). In addition, patients with anomalies in the progression of labor activity are a reserve for reducing the frequency of CS: all cases of abdominal delivery in patients, stipulated by anomalies in the progression of labor activity, must be analyzed in order to identify missed opportunities and improve the tactics of labor management in a particular institution.

In order to identify differences in indications for operative delivery in groups I+II and III+IV according to the RC, a comparative analysis of statistical data was conducted (Table 7).

The comparative analysis showed that in groups I+II according to the RC, the basis for CS was “other indications” (141 (29.2%) patients), which was significantly (p<0.001, χ2 =71.773) different from groups III+IV, in which the predominant indications were anatomical obstacles to childbirth through the natural birth canal (27 (20.6%) patients).

Patients from group V according to the RC with one scar on the uterus are considered a reserve for reducing the frequency of operative delivery. In particular, 619 patients were classified in this group and 599 (96.8%) of these patients were delivered operatively. An analysis of the structure of this group was conducted by the number of scars on the uterus in the studied cohort of patients. The largest proportion of patients in group V according to the RC consisted of women in labor with one scar on the uterus (392 (65.4%) patients). Almost a third of this cohort of women, namely 177 (29.5%), had two scars on the uterus. The smallest proportion of patients in Group V according to RC was delivered by CS due to the presence of three scars (28 (4.8%) patients), and four or more scars on the uterus (2 (0.3%) patients) (Table 8). In 3 (0.5%) patients with one scar on the uterus, the main indication for CS was complete placenta previa.

It is worth noting that if all births in patients with one scar on the uterus from group V according to the RC are performed through the natural birth canal in the presence of conditions and the absence of contraindications, then the CS rate will decrease by a total of 10% (to 43.2% cases), which makes this group of patients the most powerful reserve for reducing abdominal delivery in a level 3A hospital.

According to the RC, 256 patients were classified in groups VI and VII, of which 245 (95.7%) women underwent surgical delivery. The main indications for delivery in group VI were fetal malposition (100 (83.4%) cases) and fetal distress (10 (8.3%) cases); in group VII, those were previous operations on the uterus (43 (34.4%) cases), fetal malposition (45 (36%) cases); statistical differences between these groups were significant (p < 0.001, χ2 = 60.384). In group VII, one of the leading indications for delivery was a uterine scar.

Group VIII according to the RC included 264 patients, of whom 215 (81.4%) patients were delivered abdominally including 212 sets of twins and 3 sets of triplets. The main indications for CS in this group were the breech presentation of the first fetus (106 (49.3%) cases), malposition of the second fetus (52 (24.1%) cases), malposition of both fetuses (7 (3.2%) cases), or one or more uterine scars from previous CS operations (20 (10.2%) cases). Considering that the choice of delivery methods in multiple pregnancies is determined by many factors (gestational age, degree of perinatal risk, the number of fetuses, chorionicity and amnioticity, the position and presentation of fetuses, the expected weight of fetuses, the presence of complications in this pregnancy, the condition of the mother, the availability of informed voluntary consent), patients in this group cannot be included in the reserve for reducing the frequency of abdominal delivery⁵.

Group IX of the RC included 47 patients, who in 100% of cases were delivered by CS. According to WHO recommendations, the frequency of CS in this group should be 100%, so if a decision were made to give birth through the natural birth canal, the woman would have to be classified into other RC groups³. The main indication for CS in this group was the isolated transverse position of the fetus (18 (38.3%) women), a scar on the uterus after CS (11 (23.4%) women), and placenta previa (12 (25.6%) women).

Group X of the RC included 498 patients, and 299 (60.0%) of these patients were delivered surgically. In this group, the most significant contribution to the frequency of CS was made by pregnant women who underwent surgery due to previous operations on the uterus (100 (33.4%) patients), fetal distress (53 (17.7%) patients), severe preeclampsia with no conditions for vaginal delivery (48 (16%) patients), placenta previa (42 (14%) patients), and “other indications” for CS (28 (9.4%) patients). In fact, the only reserve in this group was patients with one scar on the uterus after CS. The analysis of patients who gave birth abdominally due to previous operations on the uterus is presented in Table 9.

The average gestational age of patients in Group X with one uterine scar after CS was 34.7 weeks. Nineteen (36.5%) fetuses in this group had low birth weight (LBW), namely <2500 g; in 33 (63.5%), cases the birth weight was within 2500–4000 g. The Apgar score of less than 7 points at the 1st and 5th minutes was in 7 (13.4%) newborns. The main indications for delivery in patients with fetal distress were decompensated forms of fetoplacental insufficiency (45–84.9%) and acute intranatal fetal distress (8–15.1%).

The analysis of indications for operative delivery, conducted in each group, explains a certain frequency of CS in each group and in the institution as a whole, which is traditionally associated with the concentration of patients at high risk for the development of obstetric complications and perinatal pathology in a level 3A hospital.

Discussion

Traditionally, most researchers use CS to determine reserves for reducing the frequency of abdominal delivery. In order to differentiate the reasons for abdominal delivery, in some few domestic and foreign studies, researchers have conducted a comparative analysis of indications for abdominal delivery. In such cases, either only indications for emergency delivery were considered [15] or different lists of relative reasons were compared. For instance, in 2019, a retrospective study assessed 4357 birth histories of patients from 13 public hospitals in Egypt only by 12 indications for CS [16]. A study conducted in Nigeria (Babcock University) in 2023 analyzed 14 indications in 447 patients. In the work of the researchers from Ethiopia, both absolute and relative indications for operative delivery were studied over a two-year period (2020–2022) [17]. In our opinion, such a non-standardized approach does not enable one to perform a comparative analysis of indications for the choice of a particular obstetric tactic and also hinders accountability and adequate assessment of trends in delivery methods both in individual maternity institutions and in the context of monitoring the CS rate between hospitals.

The generally accepted reserve for reducing the frequency of CS is related to patients from groups I–IV according to the RC. However, a detailed analysis of indications for abdominal delivery has shown that these groups include patients with absolute indications for CS such as placenta previa, premature placental abruption, uterine scar after conservative myomectomy, anatomical obstacles to vaginal delivery, somatic diseases requiring exclusion of the pushing period, threatened or incipient uterine rupture, severe preeclampsia, HELLP syndrome, or eclampsia during pregnancy and labor (in the absence of conditions for vaginal delivery). Nevertheless, in this group of women, a balanced approach with adequate assessment of perinatal risk can change obstetric tactics and conduct delivery through the natural birth canal. This is a careful selection of patients for programmed delivery and induction of labor, timely correction of labor anomalies, and the absence of hyperdiagnosis of fetal distress. It is these patients from these groups that are the main reserve for reducing the frequency of CS.

Besides, significant potential for reducing the frequency of abdominal delivery in group V of the RC is patients with one scar on the uterus, for whom, in the absence of medical contraindications and the presence of conditions, it is possible to perform delivery through the natural birth canal. Patients from group VII with a breech presentation of the fetus and no contraindications to external obstetric rotation of the fetus can also be considered a reserve for reducing the frequency of CS; in group X, those are pregnant women with one scar on the uterus without other nosologies, which complicate the course of pregnancy and childbirth.

In our opinion, only a standardized approach to auditing indications for CS in groups of RC is a vector of best practices in labor management: a low proportion of CS due to abnormal labor, cephalopelvic disproportions, fetal distress, use of ART, and/or a combination of relative indications for CS.

Conclusions

The data obtained during the conducted analysis allow concluding that, although the RC makes it possible to analyze the frequency of CS in each group, it can be compared with other hospitals. In order to structure in detail, the reserves for reducing the frequency of abdominal delivery in a specific institution and a personalized comparative assessment of this indicator between institutions, in addition to the traditional analysis according to the RC, it is necessary to develop and implement a single standardized form for analyzing indications for CS in each of the RC groups.