The present prospective study was conducted to evaluate the relationship between mode of delivery and maternal outcomes in labor ward of Sananadaj Hospital from May 2012 to May 2013. The study population included all women who were admitted for labor in Sanandaj’s Hospital. Sanandaj is the capital of Kurdistan province in Western Iran.

The inclusion criterion incompasses; patients who underwent caesarean section and operative vaginal delivery. Exclusion criteria were expulsion of the fetus before the 20^th week of pregnancy (abortion). Data collection instrument was researcher made questionnaire and was composed of three parts: the first part was related to demographic characteristics of participants (age, education, occupation, place of residence, parity), the second part was related to the problems associated with current pregnancy, and the third part included different modes of delivery (vaginal, vaginal + episiotomy, caesarean delivery, operative vaginal delivery) and maternal birth outcomes until discharge (bleeding, laceration, rupture of cervix, abnormal placental adhesion, consumption of antibiotics, blood transfusion, hysterectomy, admission to ICU and maternal mortality).

For content validity, the questionnaires were given to three obstetrics and gynecology specialists and three midwifery lecturers and necessary modifications were made on the questionnaire based on their recommendations. The reliability of questionnaire was determined by Cronbach’s alpha (r =0.88).

After approval of Ethical Committee of Kurdistan University of Medical Sciences and permission of hospital authorities, two trained midwives collected the data.

Data were entered into SPSS version 20.0 and analyzed using chi-square test. Desired outcomes were put into multivariate logistic regression. The model consists of four levels of delivery: vaginal (reference group), vaginal + episiotomy, caesarean section delivery and operative vaginal delivery. Insignificant variables were removed one by one and only significant variables remained thereafter. The importance of this model was to estimate the independent effect of caesarean section compared with vaginal delivery on the outcomes. Increased risk of caesarean section was verified by OR with a 95% confidence interval. To estimate the parameters and significance levels more accurately, bootstrap technique and a sample size of 1000 were used. The p-value of less than 0.05 was considered as statistically significant in all stages of the study.

During the study, a total of 5984 deliveries were conducted in Sanandaj’s Hospital, of which 3423 (57.20%) were vaginal (vaginal, vaginal + episiotomy, operative vaginal delivery) and 2561(42.80%) were caesarean section. The method of delivery differed significantly by age, occupation and level of education. Women aged more than 36 years old, employed and having university education were more likely to undergo caesarean delivery. [Table/Fig-1].

The results showed that maternal complication rate in Sanandaj were 101.8 in 1000 deliveries. In total, maternal morbidity by caesarean section was 10.86% vs 8.2% that of vaginal delivery. There was a statistically significant association between mode of delivery and outcomes such as bleeding rupture of cervix, use of antibiotics and hospitalization in ICU. However, no statistically significant association was found between mode of delivery and outcomes such as perineal laceration (p=0.107), uterine rupture (p=0. 481), abnormal placental adherence (p=0.593), blood transfusion (p= 0.519), hysterectomy (p=0.353) and maternal mortality (p=0.911) [Table/Fig-2].

We used multinominal logistic regression models during which vaginal delivery was chosen as the base group, vaginal delivery + episiotomy as the second group, caesarean delivery as the third group and instrumental delivery as the fourth group. Significant variables including bleeding, perineal laceration rupture of the cervix, antibiotic use and hospitalization in the ICU entered into the model and was analyzed at different levels. Multinominal logistic regression showed that the risk of bleeding during vaginal delivery + episiotomy (OR 0.69, 95% CI, 0.439-1.076) was higher than caesarean section (OR 0.40, 95% CI, 0.25-0.65). Risk of perineal laceration in vaginal delivery + episiotomy was five times higher than vaginal delivery (base) (OR 5.83, 95% CI, 0.02- 1653.828). Risk of perineal laceration for caesarean section delivery and operative vaginal delivery were not calculated because there were no cases of perineal laceration [Table/Fig-3].

The results of this study also showed that the risk of cervical rupture in vaginal delivery + episiotomy was higher than the other modes of delivery. OR for “use of antibiotics” in caesarean section was 5 times greater than other modes of delivery [Table/Fig-3] (OR 3.18, 95% CI, 2.27-4.45). In addition, vaginal delivery + episiotomy was significantly increased the risk of hospitalization in ICU compared with other mode of delivery [Table/Fig-3]. The results from bootstrap technique used in this model show that estimation of parameters were exact and had precision.

The findings of this study showed that caesarean section delivery rate in Sanandaj was 42.80% in 2012-2013 which is higher than caesarean section rate recommended by WHO (10%-15%) [17]. WHO study which was conducted in eight Latin American countries in 2005 reported caesarean section rate as 33%, also in another study by WHO in nine Asian countries during the years 2007-2008, this rate was reported as 27.3 % [16].

In general, the results of the study showed that postpartum maternal morbidity in Sanandaj was 101.8 per 1,000 deliveries. However, in international studies this rate has been reported from 3.8 to 430 per 1,000 deliveries [18].

The most important finding of this study was a positive relationship between mode of delivery and maternal outcomes. While in previous studies maternal morbidity of caesarean section deliveries had been reported as higher than vaginal delivery, but in this study, complications such as bleeding, perineal laceration, rupture of the cervix, hospitalization in ICU in vaginal delivery +episiotomy were greater than caesarean section [16-19]. In this study the risk of postpartum hemorrhage in vaginal + episiotomy delivery was greater than caesarean delivery. This finding is inconsistent with the results of Liu S et al., that reported increase of bleeding after caesarean section [15]. Although this result was unexpected because the average amount of hemorrhage in caesarean section is greater than vaginal delivery, this finding may indicate the importance of care and attention related to the mode of delivery. In caesarean section, more care and faster diagnosis and intervention is required to prevent bleeding which could potentially put the mother’s life at risk [18]. International Confederation of Midwives and International Federation of Obstetrics and Gynaecology recommend active management of third stage of the delivery for all women with the aim of decreasing post partum bleeding and its related conditions [20].

In this study, risk of perineal laceration after vaginal delivery + episiotomy was greater than vaginal delivery. Several studies have shown that complications of routine use of episiotomy are one of the factors of perineal trauma and recommended limited use of episiotomy [21-23]. In a clinical trial conducted by Dannecker C et al., two ways of episiotomy were studied. In the first group, 49 cases were included in the study who underwent episiotomy because of fetal indications and 60 other cases were included in the second group who underwent episiotomy only in case of impending rupture. Episiotomy rate in the first and second groups were 41% and 77% respectively. Researchers concluded that chance of having a safe perineum in women with limited use of episiotomy (second group) was more and they had mild perineal trauma and less pain after delivery [24].

Findings of this study showed greater rate of cervical rupture during vaginal delivery + episiotomy than caesarean section, these findings were consistent with the results of other studies [22,23]. Landy HJ et al., demonstrated that risk factors among multiparous women regardless of parity for cervical lacerations included young maternal age, vacuum vaginal delivery, oxytocin use and cerclage [25]. Although in our study causes of cervical laceration were not investigated, the cervical laceration of this study could be due to use of oxytocin and augmentation, using operative vaginal delivery as well as episiotomy (36.99%). Therefore, complications of vaginal delivery could be reduced by reducing unnecessary interventions such as routine use of oxytocin and episiotomy.

In the present study the use of antibiotics in caesarean section delivery was three times higher than vaginal delivery (vaginal, vaginal + episiotomy, instrumental delivery). These findings are consistent with the results of other studies [22, 23, 26, 27].

In general, postpartum infection is the most common complication of caesarean delivery and this infection is associated with the length of labor, rupture of membranes and diabetes [24].

This study showed that the rate of mothers’ hospitalization in ICU after vaginal delivery + episiotomy was greater than that of caesarean delivery which was inconsistent with the results of other studies [22-24]. In a study by Souza JP et al., the length of stay in the ICU after caesarean delivery has been more than what was found in vaginal delivery [27]. Also Lumbiganon P et al., concluded that, the risk of ICU stay after caesarean delivery was significantly higher than vaginal delivery [16].

The present study was comprehensive and conducted on maternal morbidity rate in Sanandaj and assessed prospectively all the deliveries during one year. Also, the large sample size was a strength of the study. A potential limitation of this study is that maternal outcomes were considered only after delivery until discharge from the hospital, while there may be some complications after discharge leading to readmission to the hospital (especially after vaginal delivery which is followed by an earlier discharge from the hospital). In addition, study hospitals were training, non training and private hospitals with different routines of care and procedures. This could affect the outcomes of delivery; however, in this study they were not investigated independently.

The finding of this study showed that caesarean section delivery rate in Sanandaj was 42.80% in 2012-2013 which is higher than caesarean section rate recommended by WHO. Also, this Study showed that there is a relationship between mode of delivery and maternal outcomes.