O&G Forum

OBSTETRICS & GYNAECOLOGY FORUM 2021 | ISSUE 3 | 15 The medical condition associated with the highest CS number was hypertensive disorders (n=1241, 14.8%). Table 2 illustrates the medical conditions and corresponding caesarean section rate. Eleven entries contained inaccurately entered information and these were taken as missing values. Table 2: Medical conditions associated with caesarean sections. Medical Condition Number of CS for medical condition Contribution to medical condition CS number (%) (n/1592) Contribution to overall CS number (%) (n/8412) Hypertensive disorders 1241 78.0 14.8 Cardiac 165 10.4 2.0 Diabetes 156 9.8 1.9 Asthma 5 0.3 0.1 Cancers 4 0.3 0.0 Epilepsy 3 0.2 0.0 Thyroid disorders 2 0.1 0.0 Others 16 1 0.2 Total 1592 100 10 The incidence of postpartum haemorrhage (PPH) between women who delivered vaginally and those who delivered by caesarean section was compared. Two hundred and forty-five (2.9%) mothers developed postpartum haemorrhage in the caesarean section group compared with 173 (2.5%) in the vaginal delivery group. There was no statistically significant difference between these two groups (p=0.132). A sub-group analysis of maternal near misses was undertaken for a 12-month period from January 2018 to December 2018. There were 3 331 deliveries during this period and 46 (1.2%) women fulfilled the criteria for a maternal near miss over this 12-month period. 11 The caesarean section numbers for women classified as a maternal near misses was 69.6%. Table 3 below shows the diagnoses and caesarean section numbers for the near miss cases. Table 3: Near miss data and caesarean section numbers Diagnosis Total Near Misses Number of CS per near miss Number of CS per near miss over total number of near misses n/46 (%) Hypertensive disorders 20 17 36 Obstetric Haemorrhage 12 9 19.5 Medical condition 8 2 4.3 Sepsis 5 3 6.5 Extrauterine pregnancy 1 1 2.1 Total 46 32 69.6 Discussion This study includes 15 295 deliveries over a 5-year study period at a tertiary referral hospital. The average caesarean section rate over the study period remained relatively constant and ranged between 52.8%-56.3% (mean 55%). This rate is higher than the rate of 50.6% reported in 2018 by another tertiary institution in South Africa. 12 The higher rate reported in our study probably reflects the increased proportion of high-risk cases managed at our institution. The major contributors to the caesarean section numbers were group 5 (all multiparous, ≥1 previous CS, ≥ 37 weeks, single cephalic pregnancy) and group 10 (all women with single cephalic pregnancy < 37 weeks gestation, including women with previous scars) and women with hypertensive disorders in pregnancy. The CS percentages in these groups were 29.0%, 22.0% and 14.8% respectively. The age group associated with most deliveries was 20-35 years. Our findings were similar to research published previously from Ethiopia where 86.7% of participants were between the ages 20-35years 13 . Previous caesarean delivery is an important contributor to CS rates. 8,12 It is common practice for women with a previous CS to opt for an elective repeat CS. 8 The Royal College of Obstetricians and Gynaecologists (RCOG), advises that women be counselled that the chance of successful VBAC is approximately 70%, 14 however lower success rates have been reported in women of African ancestry. 15,16- 18 The VBAC success rate at our institution for 2013-2018 was 36%. 15 Reasons for failed VBAC in this study included poor progress of labour, fetal distress as well as cephalo-pelvic disproportion. 15 The VBAC complication rate at our institution was low. No women attempting VBAC during the 2013-2018 study was admitted to the intensive care unit and there were no cases of uterine rupture following attempted vaginal birth. The authors reported that the low complication rate observed was most likely due to the strict VBAC protocol followed. 15 The second highest contributor to the caesarean section number was group 10, which represents the group of women who deliver preterm. The CS rate contribution from this group was 22%. The preterm birth rate over the study period at our institution was 33.6% (n=5 127). The preterm birth rate at our institution is significantly higher than the average rate in South Africa (15%) as we are a tertiary institution. 19 We will need to critically assess the causes of preterm birth at our institution, and this would possibly assist in lowering the CS rate in this group. The sub-group analysis on near miss data from January 2018 to December 2018 revealed a 69.6% CS rate among women classified as a maternal near-miss. Studies have shown that near misses are associated with increased CS rates. 20 A secondary analysis of the WHO Global and multi-country surveys showed that, compared with vaginal delivery, CS was associated with significantly increased odds of maternal intensive care unit admission, maternal near miss, and neonatal intensive care unit admission. 21 The WHO study further found that 90% of near-miss cases in obstetric haemorrhage group had caesarean sections. Maswime et al, in a study on near- miss maternal morbidity, found that prior caesarean section was a dominant risk for maternal near miss due to obstetric haemorrhage. 22 It is therefore prudent to address the two important Robson’s 10 groups (5 and 10) contributing to high caesarean section rates. We analysed the contribution of maternal medical disease to our CS numbers. Nineteen percent of caesarean sections were performed for women with underlying medical condition. The medical condition associated with most caesarean sections was hypertensive disease (14%). Looking at data from other academic hospitals, Yale showed that risk factors of CS included preeclampsia, suspected macrosomia and other maternal and fetal conditions such as placental attachment disorders and congenital anomalies. 7 A study done in Durban, South Africa, showed that preterm pre-eclampsia was associated with an increased incidence of caesarean sections. 23 In Brazil, a study done on indications for caesarean section rate saw a high rate of CS being done for severe pre-eclampsia (57%), followed by fetal distress (15%). 24 Prevention of hypertensive disorders in pregnancy is therefore prudent in reducing caesarean section rates. Both the South African Department of Health and the American College of Obstetricians and Gynaecologists recommend the use of low dose aspirin (81mg/day) in patients at risk of pre- eclampsia. The use of calcium supplementation in patients with low calcium intake has also shown benefit in reducing pre-eclampsia. In a 2018 systematic review of 27 randomized control trials, calcium use from mid-pregnancy (20weeks), to delivery approximately halved the risk of pre-eclampsia. 25 Ensuring that these strategies are implemented widely may reduce the incidence of pre-eclampsia and the subsequent caesarean section rate. O&G Forum 2021; 31: 13 - 16 ORIGINAL RESEARCH