In recent years, cases of Chinese hospital settings under violent threats have been reported and such reports have become the subject of worldwide attention.1 2 These adverse events have affected doctors and medical students in China.3 4 Violence against medical staff is not solely limited to China, but a worldwide issue.5 6 7 Nevertheless, it is unimaginable that this kind of violence could become exacerbated, and this threat has even influenced the medical education of the future Chinese generation. As the lack of trust and relationship between doctors and patients in China becomes worse, many doctors are discontented and concerned about their safety during daily work. The survival status of Chinese doctors in this special period is worthy of attention. As of now, the exact status of Chinese doctors’ quality of life (QOL) under conditions like these disastrous situations remains obscure.

A brief version of the World Health Organization Quality of Life (WHOQOL-100; WHOQOL-BREF) is one of the best known and acceptable instruments available. It has been developed for cross-cultural comparison of QOL and is available in more than 40 languages. Its validity has been confirmed in assessing the subjective QOL of patients and the general public. The Chinese version of WHOQOL-BREF has also proven to be reliable and valid in the assessment of QOL in Chinese individuals.8 9

The aim of this study was to assess the QOL of Chinese urologists from a nationwide survey10 to explore the possible influencing factors of QOL, and to generate public attention on the issue of QOL of the current medical community.

The approval for this study was obtained from the Institutional Review Board of the Second Xiangya Hospital, Central South University, China. The survey was anonymous and questionnaires did not contain information that could identify individual respondents. The administrator saved all the returned questionnaires and data drawn from the survey remained confidential.

The survey was carried out at the 20th National Urology Conference in Beijing held between 19 and 21 December 2013.10 The conference was organised by the Chinese Urological Association and was held at the China National Convention Center in Beijing. More than 2000 members registered for the conference from over 30 areas, which included participants from different provinces, cities, and autonomous regions of China. This cross-sectional study was conducted on 19 December 2013. A total of 1000 questionnaires were sent to the delegates and none of them reported repeating the test. Four well-trained investigators distributed and carried out the survey simultaneously and each survey process was limited to less than 10 minutes per participant. If participants had any questions regarding the survey, they could ask for help at any time during the process. The exclusion criteria were: (1) if more than 20% of items (5 items) were not answered in the WHOQOL-BREF questionnaire; or (2) if more than two items were not answered in the general information section, except the items of WHOQOL-BREF.

The questionnaire comprised two sections: (a) general information of respondents which included gender, professional qualifications (titles), working years, hospital location, and sources of stress including medical environment (referring to working environment and workplace safety), clinical work, research work, and promotion; and (b) the Chinese version of WHOQOL-BREF which consisted of 26 items in four domains. The four domains included in the brief version of WHOQOL-100 were physical health (PHYS), psychological health (PSYCH), social relationships (SOCIAL), and environment (ENVIR). Each of the 26 items was assigned value scores of 1 to 5. The score for each domain was transformed into a linear scale from 0 to 100, reflecting QOL which ranged from lowest to highest.

Software EpiData version 3.1 (The EpiData Association, Odense, Denmark) was used to establish the database. Double data entry was done and this was double-checked by two well-trained researchers until the results were exactly the same. Besides the questionnaires that were excluded, in the general information section of the valid questionnaires, all the missing values were replaced with medians (rounded), and for WHOQOL-BREF, the missing data were replaced with the series mean.

All the statistical analyses were performed with the Statistical Package for the Social Sciences (SPSS; Windows version 16.0; SPSS Inc, Chicago [IL], US). Cronbach’s α was used to measure internal consistency (‘reliability’), while Kaiser-Meyer-Olkin (KMO) measure and Bartlett’s test were used to assess the validity of the instrument. Data in each domain of WHOQOL-BREF were divided into two grouping variables by its mean. Binary logistic regression was carried out to analyse impact factors. A P value of <0.05 was considered statistically significant.

Of the 1000 questionnaires sent, 856 were completed and returned. Approximately 17% (148/856) were excluded according to the exclusion criteria. Among the remaining 708 questionnaires, the total missing data in the general information section and WHOQOL-BREF section were about 2.1% (15/708) and about 3.0% (21/708), respectively, and these were considered to be valid. Of the 708 respondents, 597 (84.3%) were male, and 111 (15.7%) were female. The work years was divided into groups of <10, 10-19, 20-29 and ≥30 years which was composed of 35.9%, 35.5%, 18.4% and 10.2% of respondents, respectively. Approximately 46% of the respondents came from provincial capitals like Guangzhou in Guangdong province, and municipality directly under the central government like Shanghai. The professional qualifications (titles) were subdivided into three categories: junior, intermediate, and senior titles. From the start of career as a doctor in China, doctors work approximately 5 years to get promoted from each title level to the subsequent one. In the survey, almost half the respondents held senior professional titles. With regard to stress, all the four sources of stress had two options to choose from: ‘Yes’ and ‘No’. For example, choosing ‘Yes’ in medical environment meant that respondents felt stress from medical environment, while choosing ‘No’ meant feeling no stress from this aspect. Each respondent could choose one or more than one source of stress. The results with regard to source of stress showed that 54.2% (384) felt stress from medical environment, 45.1% (319) from clinical work, 76.0% (538) from research work, and 85.3% (604) from promotion.

Reliability and validity were performed by SPSS. Cronbach’s α, the most common measurement of reliability, was used to assess the degree of internal uniformity. The overall Cronbach’s α coefficient of the instrument was 0.825, indicating the questionnaire was of good quality. Exploratory factor analysis is a mature and effective method used to uncover the underlying structure of a relatively large set of variables. Results showed that KMO measure was 0.841 and P value of Bartlett’s sphericity was <0.001, indicating that the data gathered from the study were suitable for factor analysis.

We then analysed the factors affecting each domain using binary logistic regression. Gender, titles, work years, hospital locations, and four sources of stress were entered as independent factors into the regression model. The analysis was performed by the Enter method. The Hosmer-Lemeshow test for the four regression equations were obtained: PHYS (P=0.198), PSYCH (P=0.863), SOCIAL (P=0.246), and ENVIR (P=0.959), indicating higher fitting degrees. Affecting factors are presented in detail in Table 1 and their relative risks and 95% confidence intervals are listed in Table 2. Three factors that affected PHYS domain were found to be gender, research work, and promotion. Research work and promotion were also the two affecting factors of PSYCH domain. In the domain of SOCIAL, only research work proved to be an affecting factor. In the ENVIR domain, three factors were found affecting—work years, medical environment, and promotion. All the above affecting factors were significant with P values of <0.05. The above results suggested that gender, work years, and medical environment were potential affecting factors of QOL and only influenced one domain. In contrast, research work and promotion influenced three domains of WHOQOL-BREF. Title, hospital location, and clinical work were demonstrated as non-affecting factors of four domains of WHOQOL-BREF (all P>0.05).

The reliability and validity of the WHOQOL-BREF instrument in a specialised Chinese population were analysed. The WHOQOL-BREF is used worldwide to assess QOL of different populations. The result suggests that the instrument is feasible in the assessment of QOL of Chinese medical professionals like urologists. The QOL of Chinese medical students8 and urban community residents9 have been successfully assessed using the WHOQOL-BREF and these studies have also proved the reliability and validity of the Chinese version of WHOQOL-BREF. 8 9

Usually the QOL of patients and geriatric populations are monitored with consideration. However, less attention has been placed on the QOL of health care practitioners, even physicians themselves. It is necessary to emphasise the QOL of health care facilitators when catastrophic events happen to medical staff. The QOL of health care providers (including physicians, nurses, and technicians) has been studied after the 2010 Haiti earthquake, and results suggest that health care providers have expressed dissatisfaction about their environment.11 In recent years, violence in health care settings in China has becoming increasingly fierce. More and more physicians and nurses have encountered physical attacks, light injuries resulting in psychological problems, or severe harm leading to death or disability. Living with high amounts of tension and fear, the work environment and personal life of Chinese medical staff are severely affected according to previous studies.2 12 In these situations, the QOL of Chinese physicians needs to be estimated. The study aimed to evaluate the QOL of Chinese urologists across the country.

In our study, 856 questionnaires were returned with a valid response rate of about 86% which is reasonable, and a total of 708 copies were used for final assessment. Males comprised the majority (84.3%) which may be partially derived from the characteristics of field of urology, and because fewer females prefer being a surgeon, not to mention an urologist. It is known that Chinese medical staff’s work environment and personal life are severely affected by violence happening in hospitals.1 2 In the four sources of stress in our study, only 54.2% of medical staff felt stress from medical environment, while 76.0% and 85.3% felt stress from research work and promotion, respectively. Following binary logistic regression analysis (Tables 1 and 2), titles, hospital locations, and clinical work were demonstrated as non-affecting factors in the four domains of WHOQOL-BREF (all P>0.05), indicating that these three variables may have very limited impact on doctors’ QOL in today’s world. When considering hospital location as an example, this information may provide a powerful and useful reference for recently graduated medical students in their job search. As in recently, most medical students tend to work in big cities,13 and our result indicated that the QOL of doctors living in provincial capitals and municipality directly under the central government may not be better than the other two city types, even though they might have better opportunities for further study, better life, and convenience which are driving their choice to work in big cities.

Like medical students,8 gender, work years, and medical environment proved as potential affecting factors of QOL but only influenced one domain of WHOQOL-BREF. In contrast, research work and promotion influenced three domains. These results suggest that research work and promotion might be the two most considerable sources of stress to Chinese doctors. As in recent China, with economic and technological take-off, especially the huge advances in modern medicine, Chinese doctors have to seize the opportunity and redouble their efforts to meet the challenges. Besides daily clinical work, they usually have to deal with extensive research work, and only then will they get promoted and paid well. Combining the above percentage of delegates choosing medical environment as a source of stress, it seems that although the medical environment has become worse and negatively impacts Chinese medical practice, it has not made such a powerful or deep influence to urologists’ QOL, when compared with a wider and subtle impact of research work and promotion. Nevertheless, the side-effects of deteriorating medical environment on doctors should not be ignored, as it indeed negatively affects QOL of medical staff and medical education even in the next generation.2 3 The policy-makers in China should pay more attention to protect medical staff from violent threats during medical practice and policies to improve the situation are recommended.

This study has some limitations. First, selection and response bias might exist as the survey was done using convenience sampling, was self-reported, only urologists were investigated, and no comparison on the time span and other medical specialties were analysed. Second, other factors which might affect QOL and also be associated with the factors were not included and analysed in this study.

The study indicated that the WHOQOL-BREF may be a reliable and valid QOL assessment tool for Chinese urologists. It is true that the deteriorative medical environment negatively affects medical practice in China according to previous studies and policies are recommended to improve the situation. We, however, should not be too pessimistic about it, as in today’s context research work and promotion may be the most extensive and significant affecting factors on doctors’ QOL.

The study was supported by the Fundamental Research Funds for the Central Universities of Central South University in 2013 (no. 2013zzts095). The authors are grateful to the participants in the conference who took time to complete the survey.

No conflicts of interest were declared by authors.

1. Huang J, Yan L, Zeng Y. Facing up to the threat in China. Lancet 2010;376:1823. Crossref

2. Sun S, Wang W. Violence against Chinese health-care workers. Lancet 2011;377:1747. Crossref

3. Jie L. New generations of Chinese doctors face crisis. Lancet 2012;379:1878. Crossref

4. Zeng J, Zeng XX, Tu Q. A gloomy future for medical students in China. Lancet 2013;382:1878. Crossref

5. Fernandes CM, Bouthillette F, Raboud JM, et al. Violence in the emergency department: a survey of health care workers. CMAJ 1999;161:1245-8.

6. Friedrich MJ. Human rights report details violence against health care workers in Bahrain. JAMA 2011;306:475-6. Crossref

7. Kowalenko T, Hauff SR, Morden PC, Smith B. Development of a Data Collection Instrument for Violent Patient Encounters against Healthcare Workers. West J Emerg Med 2012;13:429-33. Crossref

8. Zhang Y, Qu B, Lun S, Wang D, Guo Y, Liu J. Quality of life of medical students in China: a study using the WHOQOL-BREF. PLoS One 2012;7:e49714. Crossref

9. Xia P, Li N, Hau KT, Liu C, Lu Y. Quality of life of Chinese urban community residents: a psychometric study of the mainland Chinese version of the WHOQOL-BREF. BMC Med Res Methodol 2012;12:37. Crossref

10. Special report one: the Twentieth National Urology Conference in 2013 opens today. 2013. Available from: http://www.ynurol.com/ct_show.asp?id=557. Accessed 6 Jan 2015.

11. Haar RJ, Naderi S, Acerra JR, Mathias M, Alagappan K. The livelihoods of Haitian health-care providers after the January 2010 earthquake: a pilot study of the economic and quality-of-life impact of emergency relief. Int J Emerg Med 2012;5:13. Crossref

12. Huang SL, Ding XY. Violence against Chinese health-care workers. Lancet 2011;377:1747. Crossref

13. Xinhua: High salary and housing cannot attract medical students; candidate students prefer big cities [in Chinese]. 2009. Available from: http://news.xinhuanet.com/edu/2009-11/24/content_12528605.htm. Accessed 23 Jan 2014.

There is widespread public and professional concern about the increasing rates of caesarean section (CS). In the UK and North America, around 25% and 32% of births respectively were by CS.1 2 In Hong Kong, according to the 2009 territory-wide O&G audit report, CS rate has been around 42.1%.3 Previous CS has been the most common indication for caesarean delivery.3 In subsequent pregnancies, CS can be associated with serious maternal morbidities.4 To reduce CS rate and related morbidities, vaginal birth after caesarean (VBAC) is an alternative advocated in most developed countries.2 5 6 According to the UK and North American guidelines, induction of labour (IOL) can be offered to women with medical or obstetric indications who opt for VBAC after discussion.2 5

Unfavourable cervix, which is a common obstetric problem, can be addressed using pharmacological and mechanical methods to enable cervical ripening. In Hong Kong pharmacological method is more commonly used for IOL. In women with previous CS, the increased risk of uterine rupture is a major concern during IOL.2 5 6 7 Mechanical methods apply pressure on the internal cervical os, stretch the lower uterine segment, and increase local production of prostaglandin. There is a lack of compelling evidence suggesting increased risk of uterine rupture because mechanical devices can be readily removed when needed and are stable in room temperature. Compared to conventional Foley catheter, the double balloon catheter (DBC) has a cervicovaginal balloon in addition, allowing greater compression of the cervical os and avoiding the need for traction (Fig 1). Nevertheless, there are limited reports about the experience with the use of DBC. Regarding the question of which IOL method is suitable in women with prior CS, a recent Cochrane review stated that there was insufficient information available to conclude on the optimal method of IOL in women with prior CS.7

Since May 2013, our unit has been offering the option of DBC (Cook Cervical Ripening Balloon; Cook Medical, Bloomington [IN], US) for IOL in women with one previous CS. Therefore, we conducted a study on Chinese women with an objective to evaluate the efficacy and safety of the DBC in IOL with one previous CS and unfavourable cervix at term. Another objective was to identify risk factors associated with unsuccessful VBAC. This is one of the first studies to report using DBC for this indication in Asian Chinese population.

This retrospective study was conducted in the obstetrics unit of Pamela Youde Nethersole Eastern Hospital in Hong Kong. The unit provides tertiary care and conducts over 3000 deliveries per year. Prior to the introduction of DBC, the background CS and VBAC rates in our unit was approximately 30% and 1.9%, respectively. The overall success rate of VBAC was more than 80%. In our study, we identified VBAC cases using DBC for IOL between 1 May 2013 and 30 April 2014 through the departmental database. Clinical details were reviewed from the case notes and hospital electronic systems.

Inclusion criteria were women with one lower transverse caesarean scar and no contra-indication for VBAC who were given the option of either repeated elective CS or VBAC. Those VBAC cases requiring medically or obstetrically indicated IOL were offered DBC if the cervix was unfavourable (modified Bishop score <6) and membranes intact.

The exclusion criteria for using DBC were: women with two or more previous CS, classical CS scar, inverted T or J or low vertical incision in previous CS; previous uterine scar for gynaecological conditions, eg myomectomy, hysterotomy; congenital uterine abnormality; twin pregnancy, non-cephalic presentations, intra-uterine death, suspected fetal distress; uterine fibroids which may obstruct labour, placenta praevia, antepartum haemorrhage, leaking, clinical chorioamnionitis, suspected macrosomia (ultrasound estimated fetal weight ≥4000 g), polyhydramnios (amniotic fluid index ≥25 cm or single deepest pocket ≥8 cm), congenital fetal abnormalities; and maternal diseases or maternal infection which would contra-indicate vaginal delivery or warrant prompt delivery. Ethical approval for this study was obtained from the local institutional human research ethics committee.

Eligible patients were admitted into hospital in the evening and an initial Bishop score was obtained. Cardiotocogram for 60 minutes, and ultrasound scan to assess estimated fetal weight, liquor volume, fetal wellbeing by umbilical artery Doppler and placental location were performed. After informed consent, the DBC was inserted according to the manufacturer’s instruction. If the DBC insertion failed, women would be offered CS the next day morning. The procedure of DBC insertion in all patients was done by one investigator (KY Cheuk). The uterine and vaginal balloons were inflated in phases to 40-50 mL and 60 mL, respectively using normal saline. After insertion, vaginal examination was performed to confirm correct placement. The catheter was taped to the woman’s inner thigh without tension. Following insertion of catheter, continuous fetal heart monitoring (CFHM) was done for 60 minutes. The catheter was kept for 12 hours if spontaneous expulsion did not occur, or removed earlier if there was spontaneous rupture of membranes, excessive vaginal bleeding, fetal distress, scar tenderness, or patient intolerance. Immediately following balloon expulsion or removal, the Bishop score was reassessed, followed by an attempt to have artificial rupture of membranes (ARM) regardless of Bishop score. To reduce the potential inter-observer bias, the same investigator (KY Cheuk) assessed the Bishop score before DBC insertion and immediately after DBC expulsion or removal. Oxytocin infusion (Syntocinon; Sandoz Pharmaceuticals, East Hanover [NJ], US) was commenced if after ARM the uterine contractions remained suboptimal at a rate of 1 mU/min and the infusion rate was doubled every 30 minutes until the uterine contractions were regular at 3 minutes’ interval. The maximum dose was capped at 8 mU/min. Oxytocin was not started without membrane rupture or if the DBC was still in place; CFHM was started after ARM till delivery. Labour was managed by the attending obstetrician and midwives. Assessment of labour progress and administration of analgesia was made according to departmental protocols. Group B streptococcus prophylaxis was given according to departmental protocol. It was commenced after DBC insertion until delivery for group B streptococcus carriers.

The primary outcome was successful vaginal delivery (spontaneous or instrument-assisted). The secondary outcomes were: induction-to-delivery interval; device-removal-to-delivery interval; cervical score improvement; oxytocin augmentation; maternal or fetal complications during cervical ripening, intrapartum and postpartum period, which included failed device insertion, inability to void during insertion, intolerance of device necessitating early removal, uterine hyperstimulation, uterine rupture, fetal distress, abruption, antepartum haemorrhage, cord prolapse, malpresentation, meconium-stained liquor, intrapartum and postpartum infection, postpartum haemorrhage, readmission in puerperium period, neonate delivery with Apgar score of <7 in 5 minutes, cord blood pH of <7.2, admission to neonatal intensive care unit, neonatal sepsis, respiratory distress syndrome and neonatal death, and risk factors associated with unsuccessful induction.

Uterine hyperstimulation was defined as either the occurrence of five or more contractions in 10 minutes for two consecutive 10-minute period, or a contraction lasting for at least 2 minutes, with or without changes in fetal heart rate pattern. Uterine rupture was defined as disruption of the uterine muscle extending to and involving the uterine serosa or disruption of the uterine muscle with extension to the bladder or broad ligament.5 Uterine dehiscence was defined as disruption of the uterine muscle with intact uterine serosa.5 Intrapartum infection was defined by maternal fever of ≥38°C during labour. Failed IOL was defined as failed ARM after catheter removal or cervical dilatation of <3 cm after at least 8 hours of optimal uterine contractions.

We also conducted a literature search on PubMed, Ovid Medline, EMBASE, Cochrane library database of systematic reviews and open library using the keywords “double balloon catheter”, “Atad balloon”, “double balloon device”, “Foley catheter”, “induction”, “previous caesarean section”, and “previous scarred uterus”. Bibliographies of all relevant articles identified were searched manually to locate additional studies. We excluded non-English publications, or if the original paper was not available from various sources such as PubMed, local hospital or universities library systems and internet.

The statistical analysis was done by PASW Statistics 18, Release Version 18.0.0 (SPSS Inc, 2009, Chicago [IL], US). Fisher’s exact test was used for categorical data, while independent t test was used if normally distributed, and non-parametric test (ie Mann-Whitney U test) if highly skewed. Univariate analysis was used to assess the risk factors associated with unsuccessful VBAC. To identify the differential effect over time, Wilcoxon signed rank test was used to compare the cervical Bishop scores before and after DBC application. The critical level of statistical significance was set at P<0.05.

Twenty-five cases were identified during the 1-year study period, and one non-Chinese woman’s data were excluded. The remaining 24 cases were included for analysis. Table 1 summarises the baseline characteristics of study patients.

Figure 2 depicts the induction process and outcomes of the 24 cases; DBC was well tolerated in all cases (Table 2). There was no case of failed insertion. After DBC expulsion or removal, the cervix became favourable (Bishop’s score ≥6) in 18 (75%) cases. The improvement in Bishop score 3 (interquartile range [IQR], 2-4) was statistically significant (P<0.001). Artificial rupture of the membranes was successful in all 22 cases with intact membranes, regardless of cervical favourability. Oxytocin augmentation was required in 18 (75%) cases. Overall, 75% of cases were delivered vaginally. Among them, the median insertion-to-delivery and removal-to-delivery intervals were 19 (IQR, 13.4-23.0) hours and 6.9 (IQR, 4.1-10.8) hours, respectively. All the four women with previous vaginal deliveries had successful VBAC. Compared with cases without, the balloon expulsion-to-delivery or removal-to-delivery interval was shorter in those with spontaneous balloon expulsion or early balloon removal due to spontaneous membrane rupture during ripening (7.8 vs 3.0 hours, P=0.025). All the cases had good neonatal outcomes with cord blood pH of >7.25, 5-minute Apgar score of 10, without the need for neonatal intensive care unit admissions (Table 3). One case reported severe scar pain during oxytocin augmentation. Scar dehiscence was suspected and emergency CS performed. Dehiscence was not substantiated intra-operatively. The baby was born in good condition. Apart from a few cases of maternal complications (eg postpartum infection and postpartum haemorrhage), there was no case of uterine rupture or adverse neonatal complications.

To study the risk factors associated with unsuccessful VBAC, univariate analysis was performed using maternal age, height, body mass index, cervical Bishop score, cervical favourability after DBC removal or dislodgement, gender and birth weight of baby, gestational diabetes mellitus, history of vaginal delivery, history of successful VBAC, inter-pregnancy interval, the indication for previous CS, and the indication for IOL in the current pregnancy as variables. Previous CS for failure to progress was the only factor significantly associated with unsuccessful VBAC (P<0.001).

Few studies have investigated the use of DBC for IOL in patients with previous caesarean scars. Table 4 summarises the findings from some of the studies8 9 10 11 including the current study. Most of the studies showed significant improvement in Bishop score after using the device and a favourable cervix was achieved in 75% to 85% of cases. The overall vaginal delivery rate was 60.2% (71/118). There was one (0.85%) case of symptomatic scar dehiscence, and no adverse neonatal complications. The cervical ripening success rate in our study was comparable to those in other studies, and also our study achieved a higher vaginal delivery rate. One explanation for this would have been due to differences in the IOL protocols. Some authors would offer CS directly if the cervix failed to ripen after the DBC.9 Our practice was to continue induction with ARM and oxytocin even if the cervix remained unfavourable after the DBC. In our patients, 83.3% (5/6) in this group delivered vaginally with continued induction. A second potential reason for better outcomes in our study would lie in the differences in inclusion criteria. Some studies had excluded women with previous vaginal delivery,10 a factor known to be associated with successful VBAC. A third reason could have been differences in ethnicity. Studies have shown that ethnicity does impact VBAC success rates.12

With increasing rates of CS worldwide, it is estimated that 10% of women requiring IOL have a history of CS. However, the optimal induction method for this high-risk group is unknown. To counter unfavourable cervix with intact membranes, prostaglandins and mechanical methods such as Foley or DBC have been used. Prostaglandins appeared to be associated with a higher uterine rupture risk.13 14 Ravasia et al14 found that the relative risk of uterine rupture with prostaglandins versus spontaneous labour was 6.41, whereas the risk with the use of Foley catheter was comparable to spontaneous labour. Although infective morbidity associated with mechanical induction is a concern, the evidence is contradictory.15 16 A systematic review by Heinemann et al15 on studies using Foley catheter for IOL showed that use of mechanical devices was associated with significant increase in maternal morbidity due to infectious morbidity when compared with pharmacological agents. On the other hand, a recent Cochrane review showed no increase in serious maternal morbidity with the use of the Foley catheter.7 Further support was provided from the recent open-label randomised controlled trial PROBAAT,16 which compared Foley catheter to vaginal prostaglandin in 824 women without previous CS. The study showed that Foley catheter had similar CS rates, less uterine hyperstimulation, fewer maternal and fetal morbidities, and no increase in infectious morbidity. Although Foley catheter was featured in all these studies, DBC potentially has additional utility for an unripe cervix as it applies pressure on both the external and internal os, avoiding the need for traction and reduces the associated patient discomfort. Double balloon catheter has a larger inflated volume compared with Foley catheter (80 mL vs 30 mL) and therefore IOL with a bigger balloon volume may shorten duration of labour with better cervical dilatation.17 Nevertheless, clinical data comparing DBC with Foley catheter in the presence of a caesarean scar are lacking, while those on intact uterus are scarce and inconclusive.18 19

Table 4 summarises the results of studies using Foley catheter for IOL in the presence of a caesarean scar.14 20 21 22 23 24 It appears that DBC achieved comparable vaginal delivery rate (60.2% vs 58.0%) and similar uterine rupture/dehiscence rate (0.85 % vs 0.65%). There was no case report of neonatal death in studies using DBC while there were two cases reported with Foley catheter. One was due to uterine rupture; another was due to rupture of vasa praevia which was independent of the method of induction.23 Further research to compare the efficiency and safety of the two devices for IOL in women with previous CS is warranted. Although uterine rupture and infectious morbidity seemed rare with DBC in women with previous CS, the number of women studied was too small to allow solid conclusion on its safety.

The complication rate for VBAC attempt was highest in those who failed to achieve VBAC in the end.25 Knowledge of the factors associated with successful VBAC would therefore enable better counselling on the choice of mode of delivery. Landon et al12 in a large cohort of 14 529 women showed that previous vaginal delivery and previous successful VBAC were the best predictors of successful VBAC; the success rates were 86.6% and 89.6%, respectively. In our study, all four cases with previous vaginal delivery (including one with previous VBAC) had successful VBAC. In the study by Landon et al,12 factors associated with unsuccessful VBAC included obesity, previous CS for dystocia, IOL, birth weight of <4000 g, advanced maternal age, short stature, more than 2 years from previous caesarean, gestational age of ≥41 weeks, and previous preterm CS. Despite our small sample size, we concurred that previous CS for failure to progress was a significant factor associated with unsuccessful VBAC.

This is the first report from East Asia on the use of DBC for IOL in the presence of caesarean scar. A success rate of 75% was achieved using VBAC in Chinese women with a caesarean scar and an unfavourable cervix. The procedure of DBC was well tolerated, and no major complications were observed. Our favourable experience with DBC in Asian Chinese women lends support to further research exploring the potential of this promising modality in averting the rising CS rates in this part of the world.

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2. Vaginal birth after previous Caesarean delivery. ACOG Practice Bulletin. No. 115. American College of Obstetricians and Gynecologists; August 2010.

3. HKCOG Territory-wide O&G Audit Report: Caesarean section. Hong Kong: Hong Kong College of Obstetricians and Gynaecologists; 2009.

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6. Society of Obstetricians and Gynaecologists of Canada. SOGC clinical practice guidelines. Guidelines for vaginal birth after previous caesarean birth. Number 155 (Replaces guideline Number 147), February 2005. Int J Gynaecol Obstet 2005;89:319-31.

7. Jozwiak M, Dodd JM. Methods of term labour induction for women with a previous caesarean section. Cochrane Database Syst Rev 2013;(3):CD009792. Crossref

8. Khotaba S, Volfson M, Tarazova L, et al. Induction of labor in women with previous cesarean section using the double balloon device. Acta Obstet Gynecol Scand 2001;80:1041-2. Crossref

9. Miller TD, Davis G. Use of the Atad catheter for the induction of labour in women who have had a previous Caesarean section—a case series. Aust N Z J Obstet Gynaecol 2005;45:325-7. Crossref

10. Ferradas E, Alvarado I, Gabilondo M, Diez-Itza I, García-Adanez J. Double balloon device compared to oxytocin for induction of labour after previous caesarean section. Open J Obstet Gynecol 2013;3:212-6. Crossref

11. Ebeid E, Nassif N. Induction of labor using double balloon cervical device in women with previous cesarean section: experience and review. Open J Obstet Gynecol 2013;3:301-5. Crossref

12. Landon MB, Leindecker S, Spong CY, et al. The MFMU Cesarean Registry: factors affecting the success of trial of labor after previous cesarean delivery. Am J Obstet Gynecol 2005;193:1016-23. Crossref

13. Lydon-Rochelle M, Holt VL, Easterling TR, Martin DP. Risk of uterine rupture during labor among women with a prior cesarean delivery. N Engl J Med 2001;345:3-8. Crossref

14. Ravasia DJ, Wood SL, Pollard JK. Uterine rupture during induced trial of labor among women with previous cesarean delivery. Am J Obstet Gynecol 2000;183:1176-9. Crossref

15. Heinemann J, Gillen G, Sanchez-Ramos L, Kaunitz AM. Do mechanical methods of cervical ripening increase infectious morbidity? A systematic review. Am J Obstet Gynecol 2008;199:177-87. Crossref

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