The rate of Cesarean delivery has been increasing worldwide. In some countries, it has reached a level that demands closer attention.1 For example, cesarean delivery accounts for more than 30% of all births in the United States2 and some Latin America countries.3
In the past two decades, China has undertaken one of the greatest economic reforms in modern history. The unprecedented speed of economic development in many regions has improved living conditions substantially in a relatively short period of time. Demand for better health care and quality of life has been increasing accordingly. Probably no medical specialty has witnessed more prominent changes than obstetrics. Based on Chinese national household health surveys, the percentage of parous women who had cesarean delivery in urban China increased from 18% in 1990–1992 to 40% in 2000.4 In large cities, the proportion exceeded 50% on average. Although some hospital data suggest that cesarean delivery on maternal request (CDMR) may be the main drive behind the doubling rate,5 population-based data are lacking. The lack of population-based data is not unique to China, and in other countries is usually due to an inability to identify CDMR as an indication. Presented with a data set that prospectively identifies CDMR, we took the opportunity to examine the rate of cesarean delivery and CDMR in southeast China from 1994 to early 2006. Findings from the 1.1 million births that this study presents may provide useful information for other developing countries.
MATERIALS AND METHODS
From October 1993 through December 31, 1996, the U.S. Centers for Disease Control and Prevention and Beijing Medical University (now Peking University Health Science Center) conducted a population-based China-U.S. Collaborative Project for Neural Tube Defect Prevention.6 The study included one northern province of China (Hebei, outside Beijing) with relatively high rates of neural-tube defects and two southeastern provinces (Zhejiang and Jiangsu, outside Shanghai) with lower rates. This study established a population-based Birth Defects Surveillance System. A total of 247,831 women were recruited before pregnancy and followed through delivery. The study was detailed elsewhere.6
The surveillance system continues to register all women and infants in the catchment areas since then.7 It covers 21 cities and counties with a population of approximately 20 million. Women were registered when they came to obtain a marriage license, at the first prenatal care visit, or when they sought perinatal care services.
Information on maternal demographic characteristics and reproductive history was collected in the registry. Each woman was given a booklet that recorded demographics, medical and reproductive history, prenatal care of the current pregnancy, complications, the labor and delivery summary, and postpartum conditions. Prenatal and obstetric care providers filled in the information at each prenatal visit and after delivery. Labor and delivery information was completed by delivering midwives and obstetricians. After postpartum discharge, the booklet was collected and the information computerized. Data were sent to the National Center for Maternal and Infant Health at the Beijing Medical University for data cleaning and editing. Inquiries on missing and erroneous data were sent to hospitals for data correction.
In 2001, a computer electronic record system was established in the southeastern provinces, as this region is economically and technically more advanced. Once a woman was registered for maternity care, all hospitals and maternal and child health facilities in the corresponding county had access to the secured information. Information on each prenatal visit, labor and delivery summary, and postpartum visit was entered by the health care providers on site and uploaded to the county server each day. The county then sent the data electronically every month to the National Center for Maternal and Infant Health for cleaning and editing.
We used data from the 21 surveillance cities and counties in the southeastern provinces from January 1994 to June 2006 because the northern region did not have complete electronic records after 2000. The following women’s demographic variables were used: women’s residence (city/county), maternal age, education level (attended primary school or less, middle school, high school, college or above), occupation (farmer, worker, service, professional, others), parity (nullipara versus multipara), and maternal body mass index (BMI, kg/m2) either before pregnancy or at the first prenatal visit. Delivery hospital type (provincial, county, and township level), birth weight, gestational age (based on the last menstrual period), and infant sex (male versus female) also were used. Provincial hospitals are usually best equipped and serve as referral centers for other hospitals, whereas township hospitals are less well equipped.
The delivery information includes mode of delivery and indications for operative procedures. The choices for mode of delivery were listed as: spontaneous vaginal, assisted breech, breech extraction, vacuum, forceps, cesarean delivery before the onset of labor, cesarean delivery after the onset of labor, and other. The main indications for cesarean delivery were: fetal distress, cephalopelvic disproportionate, breech/transverse presentation, maternal complications, woman’s request, previous cesarean delivery, and other. The common reasons in the “other” category include “precious baby” (when both parents are single child in their immediate families), maternal age over 35 years, and suspected macrosomia. We did not simply use “woman’s request” to indicate CDMR. Instead, we established our own definition based on previous literature and available information in the database (see Box). Eighty-eight percent of procedures coded as “woman’s request” met the definition of CDMR. Those who were recorded as “woman’s request” but did not meet our definition are categorized as “non-CDMR.”
For data analyses, we used χ2 test for categorical variables and analysis of variance for continuous variables. We then used a log binomial model8 to examine how maternal characteristics were associated with the use of CDMR, controlling for other factors. Adjusted risk ratio (in contrast to odds ratio from logistic regression) and 95% confidence interval were expressed. All analyses were done using SAS 9.1. Use of this de-identified registry data for research was approved by the ethics committee at the Peking University Health Science Center in China and the National Institutes of Health in the United States.
From 1994 to June 2006, a total of 1,696,081 pregnancies were registered in the surveillance system. We excluded women in the following order: multiple gestations (n=14,837), gestational age less than 20 weeks (i.e., spontaneous or induced abortions, n=209,634), and births in the northern region (n=272,705). Finally, we excluded one city and one county that did not implement the electronic registry system until 2005 (n=99,155), leaving 1,099,750 singleton births for analysis.
Table 1 presents the maternal characteristics by year of delivery. Over the past 13 years, maternal age, nulliparity, mean BMI, and birth weight have not changed substantially. However, the prevalence of overweight (BMI ≥25 kg/m2) doubled from 3.8% to 8.4%. The incidence of preterm birth (<37 weeks) steadily declined from 5.7% to 3.5%. Some women changed occupation from working in service sectors to engaging in privately owned businesses. Most importantly, the educational level of women improved dramatically. The percentage of women who had high school or higher education increased from 13% to 46%. Due to the very large sample size, all differences were statistically significant at P<.05.
Figure 1 presents the overall rate of cesarean delivery and array of indications from 1994 to 2006. The overall rate increased from 22% in 1994 to 60% in 2003 but moderated to 56% in 2006 (P<.01). From 1994 to 1998, rates for almost all indications increased except for breech/transverse presentation, which has remained constant for the past 13 years. On the other hand, the proportion of missing values of indications progressively declined over the years, especially after the use of electronic records began in 2001. The rate of CDMR increased dramatically from 0.8% in 1994 to 22% in 2003 and moderated to 20% in 2006. As a matter of fact, the high cesarean delivery rate after 1998 was almost entirely due to CDMR. Should cases of cesarean delivery for woman’s request (including CDMR) be removed, the overall cesarean delivery rate would have remained by and large unchanged (fluctuating at 34–38%) between 1998 and 2006.
Table 2 illustrates risk factors that were independently associated with CDMR after all variables in the table were adjusted in the multivariable model. During the period 1994–1995, older maternal age was strongly associated with CDMR. Women who were nulliparous or had better education were more likely to have had CDMR, whereas farmers were least likely to have had CDMR. Compared with provincial hospitals, county hospitals tended to have performed more cases of CDMR, whereas township hospitals did less. Infant sex was not associated with CDMR. Large newborns were more likely to be delivered by CDMR.
The pattern of risk factors changed substantially between 2004 and 2006. The association between CDMR and maternal age, occupation, and newborn size significantly weakened or disappeared. Maternal age was no longer a strong risk factor, and township hospitals became equally likely to perform CDMR as provincial hospitals.
Nonetheless, the dynamics of change in the overall cesarean delivery and CDMR rates vary between areas. For instance, Jiaxing City is one of the most urban areas and has the highest cesarean delivery rate in the surveillance system (close to 90% between 2002 and 2004) (Fig. 2). The overall cesarean delivery and CDMR rates there were much higher and increased much earlier than in Fenghua County, which is a mostly rural area. Interestingly, while the cesarean delivery and CDMR rates in Jiaxing City began to decline in the past 2 years, those in Fenghua County are still catching up.
Our population-based surveillance data show that the rate of cesarean delivery has undergone astonishing changes in certain parts of China in the past decade. The cesarean delivery rate almost tripled at one point in 2003 (from 22% to 60%). This observation was consistent with the national household survey data.4 We further found that procedures coded as CDMR played the major role in the dramatic increase in the overall cesarean delivery rate. This is also supported by hospital-based data.9 The reasons for the very high overall cesarean delivery rate and CDMR in China are complex, but they may be grouped into clinical and social/cultural categories.
In 1998, Guo et al10 reviewed 857 cesarean deliveries in two medical university-affiliated hospitals. Fifty-four percent of cesarean deliveries had appropriate indications, whereas the rest had inadequate indications (46%). The latter included no trial of labor for suitable patients, inappropriate timing and method of induction, insufficient time for trial of labor, and inappropriate diagnosis resulting in cesarean delivery. Twenty percent were attributed to the physicians, and 26% were requested by the women. The authors also surveyed 63 obstetricians. All of them would consider elective cesarean delivery or trial of labor with loosened criteria in the following situations: “precious baby,” elder primigravida, or estimated fetal weight more than 4,000 grams.
Fu et al5 reviewed the rates of cesarean delivery and cesarean delivery for difficult labor in a university-affiliated hospital in China from 1989 to 2001. The overall cesarean rate increased from 17% to 63% in a decade. Among women who were diagnosed as having difficult labor, cesarean delivery was performed from 40% to 94% of the time, whereas use of forceps dropped from 52% to 4%. Vacuum was rarely used.
Social and cultural factors are the major contributor to the high cesarean delivery rate in China.11,12 Thanks to one-child family policy, women, especially in urban settings, are not concerned about future pregnancies. Families often desire a perfect baby and have little tolerance for risk.13 Furthermore, women are often inadequately informed about child birth. Some women fear labor pain and lack confidence in their ability to go through vaginal birth.12,14 For example, Zhu et al15 surveyed 50 pregnant women. Half of them were not informed of the birth process, 70% were not confident, and 65% thought that cesarean delivery was less painful and would not affect body shape.
Widespread myths may also influence women’s or families’ decisions regarding mode of delivery. For example, “A baby delivered by cesarean delivery is smarter; the head is better shaped.” “Women’s body shape and pelvic floor will be better protected by cesarean delivery.” And “certain dates of birth are more auspicious.”5,12–14 All these factors increase the demand for cesarean delivery despite the fact that the cost of a cesarean delivery is almost twice that of a vaginal delivery on average (RMB 4,226 versus 2,204 in 2000).15
Physician factors also may play an important role. Concerns over possible medical-legal disputes, demand from patients, and higher financial charge by the hospital for cesarean delivery may have contributed to liberal use of cesarean delivery in China.5,13,16 Obstetricians’ own beliefs also may influence the decision to perform cesarean delivery.5 Zhu et al16 surveyed 50 obstetricians and midwives. Eighty percent thought that cesarean delivery was faster and less painful. Fifty-seven percent of parous female obstetricians/midwives had undergone cesarean delivery. Fifty percent of nulliparous respondents would like to have cesarean delivery themselves.
It should be noted that the rate of CDMR in our study is likely to be underestimated still. Anecdotal evidence suggests that the “other” indications category for cesarean delivery includes a substantial proportion of cesarean deliveries for “precious baby” in our study. This should be categorized as CDMR from a clinical standpoint, but because it is lumped with all other indications, we were unable to identify it separately. In addition, our surveillance region is one of the most economically developed areas in China. This is reflected in the dramatic improvement in the education of women as more schools were built and more students could enter high school and college. Our findings, therefore, cannot be generalized to the whole country. We also acknowledge that our surveillance data on indications for cesarean delivery have not been validated. They were reported by obstetricians and midwives. However, the patterns of overall cesarean delivery rate and CDMR in our study are consistent with hospital-based reports.9,11,13 The incidence of cesarean delivery for breech presentation remains virtually the same over the 13 years from 1994 to 2006 (Fig. 1), indicating the consistency of the reporting. Furthermore, the proportion of missing values on the indications progressively declined over the years, suggesting improvements in data quality, especially after the use of electronic records began in 2001. For this study, woman’s request as an indication for cesarean delivery was freely reported by physicians, providing us a unique opportunity to study CDMR.
1. Bertrán AP, Merialdi M, Lauer JA, Bing-Shun W, Thomas J, Van Look P, et al. Rates of caesarean section: analysis of global, regional and national estimates. Paediatr Perinat Epidemiol 2007;21:98–113.
2. Hamilton BE, Martin JA, Ventura SJ. Births: Preliminary data for 2005. Natl Vital Stat Rep 2006;55:1–18.
3. Villar J, Valladares E, Wojdyla D, Zavaleta N, Carroli G, Velazco A, et al. Caesarean delivery rates and pregnancy outcomes: the 2005 WHO global survey on maternal and perinatal health in Latin America [published erratum appears in Lancet 2006;368:580]. Lancet 2006;367:1819–29.
4. Tang S, Li X, Wu Z. Rising cesarean delivery rate in primiparous women in urban China: evidence from three nationwide household health surveys. Am J Obstet Gynecol 2006;195:1527–32.
5. Fu L, Cui M, Chen J. Analysis of the factors affecting cesarean section rates and indications. Zhong Guo Shi Yong Fu Chan Ke Za Zhi (Chinese Journal of Practical Gynecology and Obstetrics) 2003;19:405–7.
6. Berry RJ, Li Z, Erickson JD, Li S, Moore CA, Wang H, et al. Prevention of neural-tube defects with folic acid in China. China-U.S. Collaborative Project for Neural Tube Defect Prevention [published erratum appears in N Engl J Med 1999;341:1864]. N Engl J Med 1999;341:1485–90.
7. Li Z, Li S, Zheng J. editors. China-U.S. Collaborative Project on Neural Tube Defects Prevention Annual Report on Perinatal Health Care and Birth Defects Surveillance 1993. Beijing, China: Beijing Medical University Press; 2000.
8. Robbins AS, Chao SY, Fonseca VP. What’s the relative risk? A method to directly estimate risk ratios in cohort studies of common outcomes. Ann Epidemiol 2002;12:452–4.
9. Lin Y, Wen A, Zhang X. Analysis on the 10-year changes of rates and indications of cesarean section. Guangdong Med J 2000;21:477–8.
10. Guo HY, Xu LZ, Zhuo YM. An analysis of factors affecting doctor’s decision on the selection of caesarean section delivery. Prac Obstet Gynaecol J 2000;16:32–4.
11. Du X, Chen YZ, Lei YL. Indication changes of caesarean section. Chinese J Reprod Health 2004;15:218–20.
12. Huang PQ, Li GY, Chen WY, Wang G, Zhang Y. The changing rate and indications of caesarean section over 12 years. Acad J Guangzhou Med Col 2004;32:57–62.
13. Feng L, Yue Y. Analysis on the 45-year cesarean rate and its social factors. Med Soc 2002;15:14–6.
14. Yao LW. A study on social factors affecting caesarean section delivery rate. J People’s Liberation Army Nurs 2003;20:17–8.
15. Zhu LP, Qin M, Shi DH, Ding Y, Xu HQ, Zhuang SL, et al. Investigation on current status of cesarean section and its effects on maternal and infant health in Shanghai. China Matern Child Health 2001;16:763–4.
16. Zhu L, Zhou B, Hua J. Study on the situation of cesarean section in Shanghai. Shanghai Med J 1999;22:349–51.