Predictors of caesarean section in Northern Ghana: a case-control study

Introduction Caesarean section rates have become a global public health. This study investigated obstetric and socio-demographic factors associated with caesarean section in northern Ghana. Methods This was a case-control study comparing 150 women who had caesarean section (cases) and 300 women who had vaginal delivery (controls). Data were collected retrospectively from delivery registers, postpartum and postnatal registers in the Bolgatanga Regional Hospital. Univariate and multivariate analysis of data were done using SPSS 22. Results The study revealed that women who had higher odds of having a caesarean section were women who; attended Antenatal care (ANC) ≥ 4 times (Adjusted OR= 2.99, 95% CI1.762-5.065), were referred from other health facilities (Adjusted OR = 1.19, 95% CI 1.108-1.337) and had a foetal weight of ≥ 4000 grams (Adjusted OR = 1.21, 95% CI 1.064-1.657). There was a slight increase in odds of having a caesarean section among women who had a gestational age > 40 weeks (Adjusted OR = 1.09, 95% CI 1.029-1.281). Women who had secondary/higher education (Adjusted OR = 0.55, 95% CI 0.320-0.941), gestational age < 37 weeks (Adjusted OR = 0.20, 95% CI: 0.100-0.412) and women who had a foetal weight of 1500 grams to 2499 grams (Adjusted OR = 0.17, 95% CI 0.086-0.339) were associated with a lower odds of having a caesarean section. Conclusion There was an increase in odds of having a caesarean section among pregnant women who had a foetal weight of ≥ 4000 grams and women who attended ANC ≥ 4 times. Pregnant women who were referred also had increase odds of having a caesarean section.


Introduction
Caesarean Section (CS) is a surgical obstetric care that is beneficial in saving lives of mothers and newborns when its indication is well grounded [1][2][3]. The decision to perform a CS should be based on obstetric history and anticipated mode of delivery [4]. Clients should be provided with detailed information on CS during prenatal care.
This ensures that clients are well informed when CS is indicated. In Nigeria it was found that higher perinatal mortality of 34% was associated with clients who refused elective CS as compared to 5% of clients who accepted the procedure [5]. The refusal for CS could be attributed to lack of detailed information on CS among clients.
Caesarean section is not only a life saving intervention but its rates have been used as an indicator of access to emergency obstetric care in population based studies [6,7]. However, like any other surgery, CS carries the risk of complications including death [8].
Caesarean section rates have become a global public health concern as the World Health Organization (WHO) observed that some countries have unacceptable high CS rates above the recommended rate of 15% [9]. Caesarean section rates have been reported to be very high. The rise in CS rates has been attributed to many factors.
Nulliparity, grand multiparity, macrosomia, hypertensive disorders in pregnancy, extremes of maternal age and cephalopelvic disproportion have been observed as indications for rise in CS rates [10][11][12][13]. Others indications documented include previous CS, antepartum haemorrhage, multiple pregnancy, maternal height, maternal weight, preference by clients and private healthcare have also been responsible for high CS rates globally [14][15][16][17]. However, increased CS rates have also been attributed to medically unjustifiable indications which makes it more alarming, hence bringing negative economic and health related repercussions [1]. This is of great public health concern as indiscriminate use of this procedure may put the health of mothers and newborns at risk. In Sub-Saharan Africa, countries like Ghana have a health system that is structured with most of the deliveries initiated in health facilities that do not have the capacity to perform CS and lack ambulances for referrals of clients who need CS [7,15]. This often leads to a lot of pregnant women undergoing emergency CS at referral hospitals with adverse obstetric outcomes as compared to clients who have been booked for parturient [15]. Although the risk factors of caesarean section have been documented globally [11,18], not much has been done to assess the predictors of CS locally within a specific Ghanaian population. This study therefore sought to determine the predictors of caesarean section. This we believe is essential for prenatal counselling in Ghana. Municipality [19]. The Bolgatanga Regional hospital is the main referral facility in the region and provides healthcare services to the entire population of the region [19,20].

Methods
Sample size and data collection procedures: Sample size was calculated using Epi info 7 with a 95% two sided confidence interval, power of 80%, two controls per case based on the formula by Kelsey et al [21]. We assumed that 15% (recommended WHO accepted CS rate) of pregnant women who delivered at the Bolgatanga Regional hospital were likely to have a CS, this was used in the calculation of the sample size [9]. Using Epi info StatCalc, our sample size was fixed at 150 cases and 300 controls (one case to two controls). The first case selected was followed by the next two successive controls as it was possible to have two successive cases.
This was repeated until the sample size was obtained. Records  [22,23]. The null hypothesis for Hosmer-Lemeshow's goodness-of-fit test of the model was fit [24]. The P value was 0.529 which is not significant, hence the model was fit.
The classification table by SPSS also showed that 79.9% of the cases were predicted accurately irrespective of whether they had caesarean section or not. This is a good model as its predictive value is 70% and above [22], the model was more appropriate as none of the interactions were significant and there were no multicollinearity problems.

Results
A total of 450 subjects (150 cases and 300 controls) were enrolled in the study. The mean age of subjects in the study was 27.5 with Standard Deviation (SD) of ± 6.9. The age of subjects reviewed ranged from 14 to 47 years. Table 1

Discussion
Our results are consistent with findings of Sørbye et al and Nilsen et al in Tanzania who reported that pregnant women who were referred were more likely to have a CS during delivery than pregnant women who walked in for delivery [7,15]. This is because pregnant women who are usually referred from other health facilities often require emergency caesarean section as referral facilities often lack the capacity [15]. This finding suggest that health facilities that lack CS services should refer pregnant women in labour with complications early enough as they are most likely to undergo CS. Macrosomia (foetal weight ≥ 4000 grams) as defined by Oluwarotimi et al was found in this study as an independent predictor of CS. This finding agrees with many other studies that identified macrosomia as a risk factor for CS [25,26] This finding is important as it would guide healthcare workers to take a timely decision of conducting a CS when a pregnant woman in labour presents with macrosomia. The findings also revealed that pregnant women with a gestational age of greater than 40 weeks were at a higher risk of having a CS. This finding is in line with results reported in studies by Osava et al in South eastern Brazil [25]. This is likely so because pregnant women with such gestational age category are more likely to have post term pregnancy which tend to be associated with higher risk of having a CS [27]. This finding is significant as it will inform healthcare workers on the need to carry out CS for pregnant women who have exceeded their expected date of delivery without having a spontaneous or induced labour. In addition, pregnant women who attended ANC 4 or more times were found to be more likely to have a CS. This is in contrast to findings of Tebeu et al in Cameroon who found no association between ANC attendance and CS [4]. This finding in our study may be due to pregnant women who were booked for elective CS as they are more likely to have their mode of delivery planned during ANC [28]. Such women often have medical or obstetric indications for CS and are often told by healthcare providers to report for ANC more frequently than their counterparts without such indications. In Italy, it was found that pregnant women with secondary/higher education had higher odds of having a CS than clients with no/primary education [29]. This is not in conformity with findings reported in our study as pregnant women with secondary/higher education had lower odds of having a CS than their counterparts with lower education.
However, our findings were in line with studies reported by Tollånes et al in Norway who argue that pregnant women with lower education had a higher risk of having a CS as they may not be well informed about their health and often report late to health facilities with complications making them more prone to CS [30].
This study also found that pregnant women with gestational age of less than 37 weeks have lower odds of having a CS as compared to their counterparts with gestational age of 37 weeks to 40 weeks. This is likely so because pregnant women with gestational age of less than 37 weeks who go into labour usually have preterm labour [31]. Preterm labour tends to be associated with low birth weight (less than 2500 grams) [32], both of which are associated with lower risk of CS [33]. In addition, low foetal birth weight in this study is associated with lower odds of having a CS as compared to neonates with normal birth weight (2500-3999 grams). This finding re-emphasis the observation made by Puliyath in the Middle East who reported that low birth weight was at a lower risk factor for CSs. In the Univariate analysis, the age group of pregnant women had no statistical association with having a CS. This is in contrast to previous studies that found extremes of age to be associated with CS [34,35]. However, our findings of no association between HIV status of pregnant women and CS agrees with studies by Calvert and Ronsmans that found no association between HIV and CS [36].
The lack of an association between HIV and CS in our study is surprising. This is because CS has been recommended for

Conclusion
This study found that pregnant women who were referred, pregnant women who attended ANC for four or more times, pregnant women with gestational age of greater than 40 weeks and pregnant women who had a foetal of weight of 4000 grams or more had a higher likelihood of delivering by CS. It will help improve on early referral of pregnant women by health facilities that lack the capacity of performing CS when it is indicated.
What is known about this topic  Pregnant women with a secondary or higher school education are less likely to have a caesarean section.

Competing interests
The authors declare no competing interests.

Authors' contributions
Paschal

Acknowledgments
We are grateful to the Upper East Regional Health Directorate for granting us permission to conduct the study. We are also thankful to the Bolgatanga regional hospital especially the staff of the obstetrics and gynaecology department for their co-operation and support.