CAESAREAN SECTION OR VAGINAL DELIVERY IN THE 21ST CENTURY ntil the 20th Century, caesarean fluid embolism. The absolute risk of trans-placentally to the foetus, prepar- section (C/S) was a feared op- death with C/S in high and middle- ing the foetus to adopt its mother’s Ueration. The ubiquitous classical resource settings is between 1/2000 and microbiome. C/S interferes with neonatal uterine incision meant high maternal 1/4000 (2, 3). In subsequent pregnancies, exposure to maternal vaginal and skin mortality from bleeding and future the risk of placenta previa, placenta flora, leading to colonization with other uterine rupture. Even with aseptic surgi- accreta and uterine rupture is increased. environmental microbes and an altered cal technique, sepsis was common and These conditions increase maternal microbiome. Routine antibiotic exposure lethal without antibiotics. The operation mortality and severe maternal morbid- with C/S likely alters this further. was used almost solely to save the life of ity cumulatively with each subsequent Microbial exposure and the stress of a mother in whom vaginal delivery was C/S. This is of particular importance to labour also lead to marked activation extremely dangerous, such as one with women having large families. of immune system markers in the cord placenta previa. Foetal death and the use blood of neonates born vaginally or by of intrauterine foetal destructive proce- Maternal Benefits C/S after labour. These changes are absent dures, which carry their own morbidity, C/S has a modest protective effect against in the cord blood of neonates born by were often preferable to C/S. urinary stress incontinence later in life pre-labour C/S. Immunological diseases With the advent of Munro Kerr’s (4). Approximately 10% of women who including asthma, atopic dermatitis and lower-segment uterine incision and the have delivered vaginally will have moder- celiac disease are more common in chil- discovery of antibiotics in the second ate to severe urinary stress incontinence dren born by pre-labour C/S compared half of the 20th century, the safety of C/S compared with 5% of women who have with those exposed to labour. The mecha- improved dramatically. As maternal risk delivered by C/S: a reduction of 5%, nisms through which C/S may cause dropped, C/S gained routine use for foetal meaning 20 C/S would need to be per- these differences are not well understood; indications. Debates arose as to how formed to prevent one case of moderate however, optimal establishment of the small a level of foetal risk warranted the to severe urinary incontinence. early microbiome and priming of the maternal risk of C/S; and routine C/S for neonatal immune system appear to have breech presentation, for example, became Neonatal Morbidity and Mortality long-term effects on childhood health. commonplace. C/S can be a life-saving operation for a Animal studies suggest that disruption Modern refinements in C/S technique foetus in jeopardy. Paradoxically, however, of this process has negative direct and have improved safety further. Regional countries with higher C/S rates now have epigenetic effects on later metabolism and anaesthesia, antibiotic chemoprophylaxis, higher rates of neonatal morbidity and immune system function (5). oxytocin, secondary ebolics, crystalloid mortality. Iatrogenic late preterm and resuscitation and blood transfusion have early term deliveries carry a significant Indications for C/S reduced mortality and morbidity to risk of neonatal pulmonary complica- Analyzing indications for C/S is difficult. very low levels. As C/S has become safer, tions, particularly for infants born by Labour is a dynamic process involving tolerance for foetal risk during labour has C/S without labour. Compliance with varying levels of risk and many foetal, decreased and C/S rates have increased recommendations to delay pre-labour placental and maternal factors. Clinician dramatically around the world. The C/S until 39 weeks gestation is variable and maternal preference also play an in- average C/S rate in 24 OECD countries and iatrogenic prematurity remains a creasing role in decisions about delivery. in 2011 was 26% and it was over 40% in significant cause of neonatal morbidity In 1996, Michael Robson published an 8 Turkey, Mexico and Brazil. C/S is now and mortality. A higher rate of stillbirth innovative system to classify C/S. Birthing so safe that some affluent women are in pregnancies after C/S also contributes women are grouped into ten mutually being offered and are seeking elective C/S to an increase in perinatal mortality. exclusive groups based on objective, without indication. The downstream routinely recorded obstetrical parameters. effects of this are only beginning to be Childhood Considerations The number of women in each group appreciated. In the United States, for the Transition from sterile foetal life to is recorded as well as the C/S rate for first time in history, maternal mortality newborn life involves rapid epithelial each group, allowing groups with high and morbidity are increasing (1). colonization with micro-organisms. C/S rates to be identified, as well as their Contact with the maternal vagina during contribution to the overall C/S rate based Maternal Risks labour and maternal skin post-partum on the size of the group. This system has Maternal mortality and morbidity is exposes the foetus to the normal maternal been used to analyze C/S rates around approximately five times greater with microbial flora. The maternal immune the world, revealing a wide variation in caesarean than with vaginal birth: spe- system has a symbiotic relationship with rates, but common themes (6). In high- cifically, the risks of hemorrhage, sepsis, this microbiome. Maternal immune resource settings, most C/S are performed venous thromboembolism and amniotic globulins are transferred antenatally, in three groups of birthing women: Andrew Kotaska parous women with a history of a prior maintain C/S rates near 15%. However, essary caesareans are performed. Com- C/S; nulliparous women in spontaneous C/S carries greater risk and cost than pared with vaginal delivery, C/S involves labour; and nulliparous women being vaginal birth; and efforts to safely avoid increased maternal risk, financial cost induced. Efforts to reduce C/S rates using unnecessary cesareans are warranted and sometimes foetal risk. Most women the Robson Ten Group Classification from the perspectives of beneficence and desire a normal vaginal birth. We have an System typically concentrate on these justice. ethical duty to help them achieve one. three groups (7). Currently, many women desiring a vaginal birth who could achieve one de- Reasons for increasing C/S rates: liver instead by C/S. Those with a breech Andrew Kotaska, MD, FRCSC, For decades, the WHO has specified 15% foetus, a deep transverse arrest, or a his- Clinical Director Maternal and as the ideal C/S rate, yet rates around the tory of a prior C/S often do not have ac- Child Services, Stanton Territorial Hospital, world keep climbing. Many factors are cess to an obstetrician or setting that can Yellowknife, NT, Canada, responsible, including: or will provide a vaginal birth. Although [email protected] • Decreasing tolerance for foetal risk the presence of a doula in labour reduces (e.g. routine C/S for breech presenta- the chance of C/S, few women around tion); the world have access to one. Instead, • Decreasing tolerance for perineal epidural analgesia, which interferes with References trauma (C/S instead of forceps the progress of normal labour, is used 1. Kuklina E, Meikle S, Jamieson D et delivery); ever more frequently. Maternal obesity al. Severe obstetric morbidity in the • Over-estimation of risk with labour increases the risk of C/S; and average or United States: 1998-2005. Obstet after prior C/S (decreased VBAC excessive weight gain during pregnancy in Gynecol 2009;113(2 Pt 1): 293–299. rates); obese women increases that risk further. 2. Villar J, Carroli G, Zavaleta N et al. • Lack of access to doula support in Improvement in labour management has Maternal and neonatal individual labour; the potential to avoid C/S by confirming risks and benefits associated with • Loss of obstetrical skills among abnormal electronic foetal monitoring caesarean delivery: multicentre pro- obstetricians (vaginal breech; opera- and assiduously augmenting women spective study. BMJ 2007;335:1025 tive vaginal delivery; vaginal twin laboring with epidural analgesia before 3. Landon MB, Hauth JC, Leveno KJ et delivery); resorting to surgical delivery. al. Maternal and perinatal outcomes • Use of electronic foetal monitoring Although C/S solely based on mater- associated with a trial of labor after without access to foetal scalp sam- nal choice occurs, it accounts for a small prior cesarean delivery. N Engl J Med pling (C/S for false positive atypical portion of the overall C/S rate. Within 2004;351:2581-9. or abnormal foetal heart rate); the bounds of maternal autonomy, there 4. Rortveit G, Daltveit A, Hannestad Y et • Increasing maternal obesity; is opportunity in many jurisdictions to al. Urinary incontinence after vaginal • Increasing induction of labour reduce the number of C/S. delivery or cesarean section. N Engl J (convenience, avoidance of post-dates Med 2003;348:900-7. risk); Summary 5. Cho CE, Norman M. Cesarean section • Increasing use of epidural analgesia In 21st century high-resource settings, and development of the immune with inadequate labour augmenta- C/S has become safe enough to allow a system in the offspring. Am J Obstet tion; rapid expansion in accepted indications Gynecol 2013;208:249-54. 9 • Maternal preference (scheduling, fear, and a dramatic increase in its frequency. 6. Brennan D, Robson M, Murphy M et avoidance of labour, convenience); The reasons for this increase are multifac- al.