CESAREAN SECTION CLASSIFICATION ACCORDING TO THE ROBSON MODEL, OBSTETRICS UNIT, SAN FELIPE GENERAL HOSPITAL, HONDURAS, APRIL-JUNE, 2017

Clasificación de cesáreas según el modelo de Robson, Unidad Obstétrica, Hospital General San Felipe, Honduras, abril-junio de 2017

Cesarean section (c-section) is a procedure whereby the fetus can be born through the abdominal (lapa- rotomy) and uterine walls (hysterotomy), when vaginal delivery becomes difficult. Etimologically, the word comes from the latin secare, which means “cut- ting” ¹. In the past, it was considered a frightful intervention because of very high rates of maternal and fetal morbidity and mortality. However, these rates have dropped thanks to the use of antibiotics, improved surgical and anesthesia-analgesia techniques, and the creation of blood banks. As a result, it has become a useful and well appreciated surgery, but this has given rise to abuse. At present, it is considered the most frequently performed surgery ¹. The growing number of c-section births exceed the frequency of 15% recommended by the World Health Organization (WHO), and is detrimental to the health systems because of increased costs associated with maternal care ². In the early 1990s, rates ranged between 16.8 and 40% ^1,3, whereas the current frequency is as high as 70% ^1,3. In a recent study carried out in 150 countries to explore the trends of cesarean sections between 1990 and 2014, the authors report a 19.4% increase in frequency (from 22.8% in 1990 to 42.2% in 2014) in Latin America and the Caribbean; 15.1% in Asia (from 4.4% in 1990 to 19.5% in 2014); Oceania 14.1% (from 18.5% in 1990 to 32.6% in 2014); 13.8% in Europe (from 11.2% in 1990 to 25% in 2014); and 10% in North America (from 22.3% in 1990 to 32.3% in 2014) ⁴. Specifically in the case of Latin America, with approximately 11 million births per year, two million births are by c-section, with a mean rate of 18% ¹, compared to figures ranging between 30% in the United States and 46% in Colombia (2, 5, 6).

Besides cost increases, c-section heightens the risk of maternal and perinatal morbidity and mortality. This intervention is associated with complications and disabilities in 12-15% of patients, with severe obstetric morbidity occurring in 0.05-1.09% of cases ^1,2,7,8. This is compounded by fetal and neonatal complications and more admissions to neonatal intensive care units ^2,5,9. The above defines the size and magnitude of a health problem that could impact the expansion of public health system coverages ^1,5,6,10. In 2014, the WHO Human Reproduction Programme recommended the Robson model for initial assessment, research into processes, and definition of strategies for reducing the number of c-sections in obstetrics units, as well as monitoring and comparisons be- tween units regarding the c-section frequency in accordance with the risk or the initial need of the pregnant woman. This model is based on categories derived from obstetrical history, the course of labor, and gestational age ^{2,5,6,8,11,12}. It has been described that for adequate decision making on high rates of c-sections, any steps taken should necessarily be based on reliable data and a simple analysis; moreover, each unit may set criteria in accordance with Robson’s groups where the largest number of c-sections are concentrated ¹³.

There is a similar trend towards an increase in the number of c-sections in Honduras. In 1985, the Latin-American Perinatology Center/Pan American Health Organization (CLAP/PAHO) reported a prevalence of 9.3% of c-sections in this country, which by 1988 had increased to 19.6% in tertiary institutions such as the Social Security Institute of Honduras (IHSS) and to 27.3% in 2014 at Hospital Escuela Universitario (HEU) ^6,14,15. The growing trend towards performing c-sections in itself represents a public health problem that may impact the workings of the entire system and must be tackled with strategies adapted to every individual hospital setting.

Consequently, the objective of this study was to classify c-sections in accordance with the Robson Model in the Obstetrics Unit of the San Felipe General Hospital in Tegucigalpa (Honduras), with the aim of evaluating the applicability of this model as an assessment and monitoring tool for identifying low risk groups taken to c-sections and defining strategies designed to limit their performance.

The proportion of c-sections over the total number of deliveries in the institution during the study period was 59.8% (477/797; 95% CI: 56.3-63.3).

In the sample group studied, mean age was 26.4 years (± 5.9; 17-43 years); the highest frequency was found in the group 18-35 years of age (92.1%). The most frequent level of schooling was complete secondary education in 23 (25.8%); 38/89 (42.7%) came from the marginal urban area (Table 1).

Table 1
Sociodemographic and clinical characteristics of pregnant women seen at HGSF, Tegucigalpa, Honduras, April-June 2017.

Source: study data.

Regarding the clinical characteristics, it was found that 77/89 (86.6%) had 37-40 weeks; 42/89 (47.2%) were primiparous; and 24/89 (27.0%) had a history of c-section. According to the classification by type of c-section, it was found that 54/89 (60.7%) were elective (Table 1).

By order of frequency, the obstetric indications for c-section in the study sample were cephalopelvic disproportion (CPD), 24/89 (27.0%; 95% CI: 18.1-37.4); low fetal reserve, 23/89 (25.8%; 95% CI:17.1- 36.2); breech presentation (complete breech), 8/89 (9.0%; 95% CI: 4-16.9); podalic presentation (incomplete breech), 6/89 (6.7%; 95% CI: 2.5-14.2); previous c-section, 7/89 (7.9%; 95% CI: 3.2-15.5); severe oligohydramnios, 6/89 (6.7%; 95% CI: 2.5- 14.2); other causes, 15/89 (16.7%) which included a history of three and two c-sections, transverse position, fetal macrosomia, contractility dystocia, condylomatosis and bleeding placenta previa. In the no-risk group, the most frequent obstetric indication for c-section was low fetal reserve, 22/89 (24.7%; 95% CI: 16.2-35.0). In cases classified as “pregnancy with no risk for c-section,” the most frequent indication was CPD and breech presentation, 8/89 (9%; 95% CI: 4-16.9).

According to the classification under the Robson model, 48/89 cases (53.9%; 95% CI: 43,0-64,5) were identified under the group of “pregnant women with no risk” for c-section (groups 1-4); in the group of “pregnant women with risk” of c-section (groups 5-10), 41/89 (46.1%; 95% CI: 35.4-57) were identified (Table 2).

Table 2
Classification according to the Robson model of categories of pregnant women at HGSF, Tegucigalpa, Honduras, April-June 2017.

Source: study data.

The results of this study show that the model is applicable in our setting in Central America. Moreover, the study found an overall proportion of c-sections of 59.8%, a high figure when compared to that reported by Jiménez et al.² in Bogotá (Colombia), who reported a proportion of c-sections of 37.0% in the study entitled “Rate of c-sections by Robson groups in an intermediate complexity institution in the city of Bogota” (“Tasa de cesáreas por grupos de Robson en una institución de mediana complejidad de la ciudad de Bogotá 2012-2014”) ². However, it is similar to the 53.10% reported by Anaya et al.¹⁶ in Popayán (Colombia) ¹⁶, and to the report by Carreño et al.¹⁷ in a comparative study between two hospitals in Chile where the proportions of c-sections were 55.7% versus 35.7%, the former being similar to the one found in this study ¹⁷.

According to the results derived from the application of the Robson model in the obstetrics unit, it was found that the low risk groups (groups 1 and 2) accounted for 19 to 22% of the total number of c-sections performed. Group 5 contributed with 21% of the c-sections, similar to the report by Vargas et al.¹⁸, who determined that group 5 accounted for the largest proportion at 65.2%, and similar to the figure reported by Smithies et al.¹⁹ at 75.1% in Canada ¹⁵. Our results regarding the frequency of c-sections in pregnant women considered to be at low risk are lower than those found in a WHO report of a study carried out in 120 obstetrics centers in 8 Latin American countries that included 97,095 women; it reported that pregnant women classified as low risk for c-section accounted for 60% of the proportion of c-sections performed. In that study, the contribution by groups 1 and 2 to the proportion of c-sections was 18.3% and 15.3%, respectively ¹⁰, similar to the finding in our study ¹⁰. Consequently, groups 1, 2 and 5 appear to be the potential targets for the implementation of a process of field research. The finding for group 5 is consistent with the report by Aleem et al.²⁰ in a large series studied in Egypt in 2016, which found that group 5 contributed with 25.5% of the cases; however, excess number of c-sections in the group classified as no-risk was 14.2% in total (Robson groups 1-4), lower than the figure of 53.9% found in this study (Robson groups 1-4) ⁽¹⁹. In contrast, in the study by Anaya et al.¹⁶, the groups with the largest contribution of c-sections were 5, 8 and 9, although the highest contribution came from group 5, at 12.17% ¹⁷.

The strengths of this study include the use of a probabilistic random selection and the application of the tool exclusively by the author. This ensures uniformity at the time of applying the Robson model for the classification. In terms of limitations, the study period was short and it could have been extended had more resources been available. Additionally, pregnant women who did not undergo c-sections were not included as was the case in other Latin American reports ¹¹, since only patients taken to c-section were included.

The applicability of the Robson model to the classification of c-sections as a tool to diagnose and monitor the proportion of c-sections in a Level II institution is demonstrated. Regular surveillance of c-section indications helps identify opportunities for institutional performance improvement in order to comply with WHO recommended frequencies. Further studies are required to assess interventions in those groups in which c-sections could be avoided.

We wish to thank doctor Carlos Ochoa for helping make this research possible; and doctor Neyra Padilla for her review of the manuscript.