Open Journal Systems

CLINICAL AND SURGICAL PRACTICE

Received: February 25^th 2015

Accepted: May 15^th 2015

Caesarean section: History, epidemiology, and ethics to diminish its incidence

Gerardo Jesús Martínez-Salazar,^a Pedro Mario Grimaldo-Valenzuela,^b Gloria Gabriela Vázquez-Peña,^b Carlos Reyes-Segovia,^b Gabriela Torres-Luna,^b Gabriela Virginia Escudero-Lourdes^b

^aDepartamento de Ginecología y Obstetricia, Unidad Médica de Alta Especialidad 23, Instituto Mexicano del Seguro Social, Monterrey, Nuevo León, México

^bDepartamento de Ginecología y Obstetricia, Hospital General de Zona 1, Instituto Mexicano del Seguro Social, San Luis Potosí, San Luis Potosí, México

Communication with: Gerardo Jesús Martínez-Salazar

Telephone: (81) 8150 3132, extensión 41350

Email: dr.gmtz@gmail.com

Cesarean section has become the most performed surgery and it has been enhanced with the use of antibiotics and improvement in surgical techniques. The aim of this systematic review is to describe and clarify some historical and ethical characteristics of this surgery, pointing out some aspects about its epidemiological behavior, becoming a topic that should be treated globally, giving priority to the prevention and identification of factors that may increase the incidence rates. Today, this “epidemic” reported rates higher than fifty percent, so it is considered a worldwide public health problem. Consequently, in Mexico strategies aimed at its reduction have been implemented. However, sociocultural, economic, medicolegal and biomedical factors are aspects that may difficult this goal. As we decrease the percentage of cesarean section in nulliparous patients, we diminish the number of iterative cesarean and its associated complications. This aim must be achieved through the adherence to the guidelines which promote interest in monitoring and delivery care in health institutions of our country.

Keywords: Cesarean section, Obstetric labor complications.

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Caesarean section is a procedure that allows the birth of the fetus through the abdominal wall (laparotomy) and uterus (hysterotomy), when vaginal birth is difficult.¹ Etymologically, it comes from the Latin secare, meaning to cut.² Before, it was considered a frightening intervention because it produced high rates of maternal and fetal morbidity and mortality, which have decreased with the use of antibiotics, better surgical techniques, anesthesia, analgesia and the creation of blood banks, so it is a useful and much appreciated surgery. This has led to its abuse, and it is statistically considered the most practiced major surgery in current days.^3-7

Cesarean section in history

In Imperial Rome newborns born in this way they were called Caesares, but the real origin of its name has been the subject of multiple and questionable versions. The most popular comes from the birth of Julius Caesar, who according to Pliny the Elder, came into the world and was named so due to his mother's uterus being excised, caesus, meaning cut.²

Most authors believe that the true creator of the name of cesarean section was the French physician Francois Rousset (1530-1603) who mentions a section césarienne in his monograph published in 1581 on the intervention entitled Traitte Nouveau de L'hysterotomotokie ou enfantement cesarien (New treatise on hysterotomy or cesarean birth), where it is recommended for the first time as a medical procedure on a living woman. This book argues that the uterus should not be sutured, which was accepted as undisputed truth. Paradoxically, Rousset, who formed his views on a caseload of few successful caesareans, did not perform any of these himself, nor did he ever attend an operation as a spectator.⁸

Another possible origin derived from Roman law of Numa Pompilio, ruler of Rome between 672 and 715 BC; a law that under the Caesars would have had the nickname of cesarean section and which imposed abdominal extraction post mortem to save the fetus, "The Lex Regia prohibited to bury a woman who died during pregnancy, before extracting the fruit via abdominal excision. Who work against this obviously destroys the hope of a living being".⁸ The church proclaimed this repeatedly through the councils of Cologne (1280), Vienna (1311-1312), Langres (1404), Paris (1557), and Sens (1574), with respect to caesarean section in the dead woman, declaring it obligatory to open the late mother's womb, provided there was reason to believe that the child was still alive. So, until the sixteenth century caesarean section was performed only in the dead mother to save the fetus, but because of the delay, its survival was also rare.²

The first reference to a cesarean section on a living woman corresponds to that practiced by the Swiss pig gelder Jacob Nufer, who performed it on his wife successfully for mother and son in the year 1500.² However, the first case historically accepted without objection was done in 1610 in Germany by the surgeons Seest and Trautmann on the wife of a cooper, who at the end of her pregnancy was seriously wounded by the arrow from a bow caught in the belly, producing a uterine rupture. The child survived, but the mother died at 25 days from sepsis.⁹ Thus, in the seventeenth century, the most important obstetricians such as the German Solingen Cornelius (1641-1687) and the French Francois Mauriceau (1637-1709) condemned this operation in living women because of the deadly outcomes for the mother.⁸ In New Spain it was decided in 1772, to do caesarean section immediately after the death of the mother to remove the fetus, living or not, and to perform his baptism.¹⁰

In 1793 the first successful caesarean section was done in England and a year later in the United States. In 1820, the Spanish doctor Alfonso Ruiz Moreno in Venezuela performed in the first cesarean vitam in Latin America, the patient died two days after surgery, but the child managed to survive.⁸

For the development of cesarean section it was necessary to find solutions to two key issues: pain relief during surgery and the prevention and treatment of infections. The pillars of this development are named after James Young Simpson (1811-1870) who introduced the use of chloroform in obstetrics; Ignaz Semmelweis (1818-1865) who first recognized the cause of puerperal fever; Louis Pasteur (1802-1895) who proved the existence of bacteria and envisioned their role in infections, an issue proved by Robert Koch (1843-1910), and Joseph Lister (1827-1912) who introduced the aseptic treatment of the operation area.⁸ One of the controversial issues associated with cesarean delivery from 1581 was the suturing of the uterine incision. In 1882 German gynecologists Ferdinand Adolf Kehrer (1837-1914) and Max Sänger (1853-1903) successfully introduced the silver and silk suture to close the uterus after cesarean section. The Sänger technique consisted of longitudinally operating on the body of the uterus on its anterior surface, which was established as the classic operation. Kehrer meanwhile, successfully practiced transverse incision in the lower uterine segment. In 1921, the Englishman J. Munro-Kerr rediscovered the Kehrer technique and in 1926 introduced the cross or crescent incision in the uterus, instead of the vertical incision in the midline, making it the ideal technique of hysterotomy in the 20^th century.²

In Mexico, it was not until September 1877 that the first caesarean section was performed on a living woman, in Monterrey, Nuevo Leon, by J.B. Meras and J.H. Meras, on a woman with exostosis of the sacrum and stillbirth. The mother recovered and walked at twenty days.^10-12

Whereas the main causes of maternal mortality associated with caesarean section were hemorrhage and uterine infection, it was necessary to exclude the uterus, which in 1876 marked a new era in the caesarian section, when the Italian surgeon Edoardo Porro (1842-1902) described the first cesarean followed by subtotal hysterectomy successful for the mother and child.^2,8

Epidemiological behavior

In the early nineties, high cesarean rates were a phenomenon of the Latin American countries. In the countries studied, cesarean section rates ranged between 16.8 and 40%. Today, this "epidemic" seems to have spread worldwide.¹

In recent decades this surgery has increased. For example, in Italy it rose from 6.0% in 1974 to 29.0% in 1986; in the United States between 1965 and 1986 it increased from 4.5 to 24.1%, and in Scotland from 7.1% in 1980 to 10.7% in 1996. It is important to note that the observed increase in the use of CS has not been a phenomenon exclusive to developed countries.⁵ There are several reasons for this, such as the decrease in mortality with the advent of antibiotics, improved anesthetic and surgical techniques, availability of blood banks and maternal and neonatal intensive care units. Current technology allows us to closely monitor fetal well-being and new indications for cesarean have appeared.^13,14

Nearly 11 million children are born in Latin America each year. There has been an increase in caesarean section rate from 15 to 35% in recent years, representing 2 million additional caesarean sections per year. In developed and developing countries for each 1% increase in the cesarean rate, costs increase by 9.5 million dollars.¹

The increase in the frequency of this surgery is considered a public health problem in the world, and Mexico is no exception. In our country, this remarkable increase in the number of cesareans without justified indications in public and private sector institutions has been a concern for the Sistema Nacional de Salud, so the Secretaría de Salud, the Federación and the Asociación Mexicana de Ginecología y Obstetricia, as well as the Asociación Mexicana de Obstetricia y Ginecología Infantojuvenil have joined forces to implement strategies aimed at reducing it.¹⁵

In proportion to the decreasing percentage of Caesarean sections in primiparous patients, the number of iterative cesareans will also decrease. So, overall one of the leading causes of cesarean section will be reduced, which together with cephalopelvic disproportion represents 53.4% of cases. Dystocia represents up to a third, while the breech presentation and low fetal reserves represent 10% of indications.^1,16

Although the Norma Oficial Mexicana establishes that the initial rate recommended for Caesarean is 15% for second-level hospitals and 20% for third level, in some countries the possibility is accepted that this incidence could be up to 29%.¹⁷ At present, some reports show rates in Mexico above 40%, an increase that is based on multiple factors: technological advances, changes in cultural patterns, professional and economic aspects, associated maternal and fetal morbidity and mortality, the proportion of patients referred to third-level care centers, increasing average maternal age, especially in nulliparous patients, use of electronic fetal monitoring, decreased use of forceps and vacuum, increasing prevalence of obesity during pregnancy, the practice of defensive medicine for fear of legal problems, and, finally, the misuse of evidence and departure from clinical practice guidelines and institutional regulations.^1,18

During 2013, the World Health Organization (WHO) reported for the 2005 to 2011 period, figures close to what is established in Sweden (17%), France (21%) and Argentina (23%); at the other end, Germany (32%), Australia (32%), USA (33%), Portugal (36%), Korea (37%), Chile (37%), Mexico (39% reported), Iran (40%), Mauritius (44%) and Brazil (52%).¹⁹ In Mexico, there was an increase of almost 3% compared to the 2009 report (2000-2008).^20,21

Regarding the age of pregnant patients, Cuban and American demographers have identified a rejuvenation of fertility and point to pregnancies at younger ages, reporting that up to 50% of adolescents between 15 and 19 years have active sexual lives.²²

Indications for cesarean

Differences in attitudes of obstetricians are not based on specific medical evidence, but on cultural factors, legal responsibility and the variables related to the specific organization of perinatal care. We should put more emphasis on understanding motivation, values, ​​and the fear underlying a woman's request for termination of pregnancy by elective cesarean.²³

Muñoz et al.,¹⁸ in 2011, in their analysis of the indication for cesarean section show an enormous list of 45 diagnoses, which they summarized by frequency and tried to integrate into groups according to the most frequently reported indications. It was found that the number one cause is the low fetal reserve followed by iterative cesarean, unfavorable cervix, premature separation of normal insertion placenta, cephalopelvic disproportion, stagnant dilation, and dystocia.

This wide range of diagnoses shows a simple way to choose any of them to justify surgical intervention, coupled with the good intentions of surgical technique, the decrease in anesthetic risk, better medical treatment that includes a shorter hospital stay, and routine administration of antibiotics, it becomes very attractive to choose surgery and forget or ignore basics of professional and ethical responsibility, from which arise sentences like: "If it doesn’t come out the bottom, it comes out on top." Even when questioning patients about surgical history, they often indicate other surgeries but not cesarean section, that is to say, it is not given the importance as it is, a real surgical event not without risk and complications.¹⁸

Maternal or medical decision?

Attributing the increased incidence of the surgical procedure to one or a few causes ignores the complexity of the problem. Cultural, socio-economic, medico-legal and biomedical factors are crucial, difficult to correct, and harder to compare in performing the procedure. For example, De la Fuente and De la Fuente,²⁴ surveyed 1222 members of the Sociedad Española de Ginecología y Obstetricia in 2006, on the decision to do cesarean section at the request of the patients. 57.8% would not do a Caesarean section on a primiparous patient with a normal fetus with cephalic presentation who requested the operation; in contrast, 93.8% answered affirmatively when this primiparous patient in normal conditions has a breech fetus.

In recent years the role the patient should play has become increasingly important in the process of diagnosis and treatment. It is said that they should be involved in decision-making, guided by information given by the doctor, who must stop being paternalistic and ask the opinion of the mother, who will record her choice by signing an informed consent. The reasons given by the pregnant women who wish to terminate pregnancy by Caesarean section are, among others, believing it possible to avoid bad perinatal outcomes and complications of the pelvic floor, both urinary and fecal incontinence.²⁵ Although vaginal birth is the natural and most frequent way to give birth, there is much scientific evidence on the safety and potential benefit of ECS in pregnant patients.¹  

The question is: Is it ethically valid for a woman to decide the mode of delivery of the fetus? The reasonable answer seems to be yes if we consider one of the core principles in bioethics, that is, the principle of autonomy. Seen in this premise, then the duty of the medical team and the obstetrician is to give the woman all relevant information, of course free of jargon, so she can make a proper deliberation and choose the path of birth of the fetus, which implies an exercise by the doctor not only humility to see themselves as equal to the patient, but of openness and sensitivity to other ways of seeing reality, that is, leaving aside the "empowering" of the patient, and in any case with the advantage of also sharing responsibilities. For all the academic and scientific rigor that is applied to analyze this situation, it is not possible to find a clear explanation, and this is because obstetricians have many ways to disguise the indications of a Caesarean. We write diagnoses like "cephalopelvic disproportion" to then extract a newborn of 2.7 kg; or "low fetal reserve" with Apgar 9-9. Of course, in all these cases we convince women to be subjected to surgery to "prevent" damage to the newborn, but in many cases none of said risks are seen.²⁶

For the above reasons, cesarean section is the most often performed surgery in all secondary care hospitals in the health sector and even more in private hospitals.¹⁸ There are many causes that have traditionally been associated with this detected increase, highlighting isolated medical staff factor as the most influential for cesarean to be done.²⁷ The doctor’s fears of being sued by the patient forces them to try to justify this procedure and practice defensive medicine;¹⁸ paradoxically, in Mexico, the Comisión Nacional de Arbitraje Médico (CONAMED) reports that 46.3% of ob-gyn complaints are related to cesarean operations.²⁸

Vallejos-Paras et al.²⁹ designed and validated a clinimetric tool for evaluating sociodemographic characteristics of the ob-gyn physician, their preferences in pregnancy resolution, attitude about cesarean sections without medical indication and on maternal request, as well as their views on the right to decide the mode of delivery. Such instruments allow one to know doctors’ preferences and modify interventions that are not supported.

Complications and risk factors associated with cesarean

In Mexico, the main causes of maternal death are hypertensive disorders related to pregnancy, childbirth and postpartum, hemorrhage, thromboembolic disorders and sepsis.^30,31 Controversially, evidence supported with methodological rigor states that cesarean delivery is associated with complications, Among the most frequent are the same causes of death identified, except for the hypertensive disorders, namely: infections, bleeding, thromboembolic events and in addition visceral lesions. Complications range from 12 to 15%.¹⁷ The incidence of severe obstetric morbidity is between 0.05-1.09%; it has also been shown that maternal mortality after cesarean is six times higher than after vaginal birth, although this increase is halved with elective caesarean.³² Thus, intraoperative and postoperative complications of cesarean are potentially serious and increase both the risk of maternal, fetal and neonatal mortality, and length of hospital stay.^17,32

Because of its frequency, the development of infections is one of the main reasons for rehospitalization, mainly because of surgical wound conditions.³³ Among the factors that have been identified as conducive to the development of this complication are: overweight, ruptured membranes for over six hours, emergency cesarean, socioeconomic conditions, number of vaginal revisions, nulliparity, chorioamnionitis, surgical blood loss volume, the presence of infection elsewhere, and preeclampsia.^33,34 However, this complication does not exceed 10% when prophylactic antibiotics are used, and its prevalence is still lower when surgery is performed with intact membranes without labor.³³ It has even been shown that the wound becomes infected almost 12 times more than that of episiorrhaphy.¹³ Decidual endometriosis and abdominal sepsis are also described, but with a prevalence reaching only 0.1% of cases.³²

One of the scenarios seen most frequently in recent years is one in which vaginal delivery is attempted in patients with previous cesarean. In this regard, a success rate of between 72 and 76% are described; this rate increases to 90% if there has been a previous birth.³⁵ Factors that can decrease the rate of vaginal birth after a cesarean are: if the previous cesarean had been because of dystocia, non-use of obstetric analgesia, prior preterm delivery, and if the period between pregnancies since the previous cesarean is less than 18 months.^36,37 Uterine rupture during labor is a serious but rare complication in the attempt of vaginal birth after cesarean.^38,39 Measuring thickness of the lower uterine segment by ultrasound during the third quarter is a tool to identify patients at high risk and reduce cases of uterine rupture in pregnant women with previous cesarean contemplating vaginal birth.^38,40 The absolute risk of this complication ranges from 0.5 to 4%.⁴¹ There is an inverse correlation between the thickness of the lower uterine segment and the risk of incident at the uterine scar, but there is still controversy in the cutoff to use.^38-40 Different studies set the safety limit at 2.3 and 3.5 mm. Although it has been said that a uterine segment with 1.4-2 mm myometrium thickness correlates with an odds ratio (OR) of 11.2 for uterine rupture,^38,39,41-43 more evidence studies are need to standardize an imaging technique that is clinically useful as a predictor of uterine rupture.^42,43  

The frequency of hemorrhage associated with elective caesarean section is less compared to emergency caesarean and childbirth.¹ In Instituto Mexicano del Seguro Social, the most common cause of obstetric hemorrhage was uterine atony isolated or associated with other morbidity processes.⁴⁴ In Mexico, in 2010, obstetric hemorrhage came second (19.6%) as a direct cause of maternal death.⁴⁵ Traditionally, this complication is defined as blood loss with any of the following criteria: loss of 25% of the total volume, hematocrit decrease more than 10%, hemodynamic changes, loss of more than 150 ml / minute, or blood loss of more than 500 ml after birth or more than 1000 ml after cesarean section. However, blood loss in these cases is sometimes underestimated.⁴⁶ Reasons for obstetric hemorrhage in the first half of pregnancy are abortion, trophoblastic disease, and ectopic pregnancy. During the second half of pregnancy, according to the stage in which bleeding occurs, it can be divided into bleeding antepartum, during labor (mainly disorders of placental insertion) and postpartum. Postpartum hemorrhage is divided into: primary or early obstetric hemorrhage, which occurs in the first 24 hours (whose main etiology is uterine atony, followed by cervicovaginal or birth canal trauma) and secondary or late bleeding, occurring after 24 hours but before 12 weeks postpartum (retention of placental remains, infection and bleeding disorders).⁴⁴

Regarding placental attachment disorders, the evidence shows that the risk factors for placenta previa and placenta accreta are maternal age more than 35 years, multiparity, smoking, and previous uterine scar (implemented curettage, manual vacuum aspiration, caesarean section, myomectomy).^46,47 It is essential to identify patients with one or more of these risk factors associated and perform ultrasonography to confirm the site of placental implantation after 28 weeks gestation.⁴⁸ Patients at high risk of obstetric hemorrhage must be sent to second or third level of care, at about the 28^th week of pregnancy or earlier in case of transvaginal uterine bleeding. Vaginal transducer ultrasound at the second and third trimesters in women with suspected placenta previa has a sensitivity of 87.5%, specificity 98.8%, positive predictive value (PPV) of 93.3% and negative predictive value (NPV) of 97.6%.^49,50 Patients with a history of placenta previa, previous cesarean and current suspected abnormal placental insertion, are at high risk of placenta accreta.⁵¹ Doppler ultrasonography for diagnosing placenta accreta has a sensitivity of 82.4% , specificity of 96.8%, a PPV of 87.5% and NPV of 96.8%.⁵⁰ It is estimated that the relative risk of developing placenta accreta in women with placenta previa is 35 times higher with a history of cesarean section than without it; there is also a 40% increase seen in the risk of premature separation of normal insertion placenta in those whose pregnancy previous to the one studied ended in cesarean.¹

Bleeding in pregnancy, childbirth or postpartum is an emergency, because survival is only 60% if action is taken in the first 20 minutes.^44,45

Some other complications associated with cesareans are adhesions as a potential cause of infertility, however, in comparing different ways of resolving the pregnancy, we have not found significant differences.¹ Postpartum depressive symptoms were more frequently associated with caesarean section; however, at 3 months postpartum there are no significant differences.^1,5

Regarding socioeconomic characteristics and associated risk factors, it is noted that women with higher education, higher income, urban residents with private health insurance, or those treated at private medical units have a higher risk of being subjected to cesarean.⁵ In addition, the conditions that mothers can present have changed and they now have a higher body mass index with deteriorating nutritional status, are older or very young, and have diseases that previously did not allow pregnancy; This group of patients are also at high risk of cesarean operation.²²

Strategies to reduce the incidence of cesarean section

WHO in its document Recommendations for Appropriate Technology for Birth, Fortaleza Declaration drafted in 1985, stresses that "there is no justification for a cesarean rate greater than 10-15%” and "vaginal delivery should be favored in patients with previous cesarean".⁵²

Clinical practice guidelines (CPG) are an appropriate tool to reduce the frequency of cesarean section. Its constant updating by unifying criteria in the indications for surgery and its application in a specific population contributes to lowering the unjustified practice.^15,53

Recently in our country we have described strategic plans to reduce the incidence of cesarean section, where it is stated:^16,18,53,54

• The application of a childbirth protocol based on scientific evidence has been shown capable of significantly reducing the rate of caesarean sections.
• Getting a second opinion before surgery, especially in primiparous patients, with clinical correlation between pre and postoperative feedback for analysis and diagnosis.
• Providing an opportunity for labor, to the extent possible, for patients with relative indication of cesarean section according to CPG.
• Avoiding loss of information, gathering full details of the patient, including the summary sheet of prenatal care for a daily review of records of patients who are undergoing cesarean section.
• Monitoring and caring for labor, proper registration in the childbirth graph.
• Analysis of information reduces cesarean section due to dystocia.
• Establishing evaluation committees of the clinical record exclusively for caesarean section, evaluating and proposing changes based on the results.

Such measures rooted in evidence-based medicine, should be promoted more to be implemented by health personnel. Encouraging surveillance and care in labor and its complications are the precepts that should be given priority and applied routinely in our health institutions in order to reduce the incidence of cesarean section.

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