Prevalence Of Cesarean Section And Risk Factors Among Kunshan City, Jiangsu Province

Objective1. To explore the prevalence of Cesarean Section （CS）, including Unlabored CesareanSection （LCS）, Labored Cesarean Section （UCS）, and Cesarean Delivery for MaternalRequest （CDMR）, and forecast the prevalence of CS in the following5years.2. To identify the association between maternal and fetal characteristics for UCS andLCS.3. To identify the association between Gestational Weight Gain （GWG） and UCSand LCS.4. To identify the association between maternal and fetal characteristics for CDMR.MethodsThis population-based retrospective cohort study was conducted between January2001and September2009in the Kunshan City, Jiangsu Province, China. Data wereretrieved from Perinatal Monitoring System of Maternal and Child Health Care Hospitalof Kunshan. The study population was consisted of33,039women and singleton livebirths, and excluded those who had the history of CS. GWG was defined as theTotal-GWG during the last and the first antenatal care divided by the interval weeks. CSwas categorized as UCS and LCS. And according to the reasons of CS which labelled asmaternal requested, were termed as CDMR. The World Health Organizationrecommended Asian standard for Body Mass Index （BMI, calculated as weight（kg）/[height （m）]²]） classifications were adopted: underweight, less than18.5; normalweight,18.5-22.9; overweight,23.0-24.9; and obese,25. We performed the multiplelogistic regression model to measure the independent association between maternal andfetal characteristics for mode of delivery, while adjusting for potential confounders, andthe Prevalence Odds Ratio （POR） with95%Confidence Interval （95%CI） wascalculated. All tests were two-sided, P <0.05was regarded as statistically significant.Statistical analysis was conducted using SAS-PC Version9.2（SAS Institute Inc., Cary, NC, USA）.Results1. The overall prevalence of CS was41.7%and in a downward trend year by year,LCS and UCS were36.0%and5.7%, respectively. The prevalence of CDMR was8.7%,and showed in a upward trend year by year, which goes up from5.8%in the year2001to10.9%in the year2009（trend test, P<0.0001）.2. We conducted a forecast for the prevalence of CS in the following5years usingGrey Model. The results indicated that overall prevalence of CS were showed adownward trend for the year2011-2015, it32.50%,31.46%,30.46%,29.49%, and28.54%, respectively.3. As for LCS, after adjusted potential confoundings each other （maternal age,education levels, hospitals when first antenatal care, parity, weight for first antenatalcare, BMI of first antenatal care, birth weight, birthweek and year of the birth）, maternalage less than24years, manual workers, education more than13years, BMI less than18.5kg/m2, preeclampsia and low birth weight were associated with decreased the riskof LCS.Maternal age more than30years, hospitals when first antenatal care was township,overweight and obesity, moderate and severe preeclampsia, parity, male fetus,macrosomia, and postterm were associated with the increased the risk of LCS.4. As for UCS, maternal age less than24years, BMI less than18.5kg/m2coulddecrease the risk of UCS.Maternal age more than30years, hospitals when first antenatal care was township,overweight and obesity, moderate and severe preeclampsia, parity, history of habitualabortion, history of induced abortion, male fetus, macrosomia and low birth weight, andpreterm or postterm were associated with the increased the risk of UCS.5. Subjects with GWG in4^th quatantile have highest prevalence of LCS inunderweight group （POR=1.51,95%CI:1.07².14） and normal-weight group（POR=1.48,95%CI:1.23¹.77）, however, we did not find the association betweenGWG and LCS in overweight and obese individuals. We also found the associationbetween GWG and incident UCS in underweight group （POR=1.55,95%CI:1.31¹.85）for the4^th interquantile, and overweight obese group （POR=1.25,95%CI:1.06¹.46）for the4^th interval. Higher GWG was associated with increased UCS risk in normal-weight group （POR=1.67,95%CI:1.52¹.83） for the4^th interquantile.6. As for CDMR, after adjusted potential confoundings, maternal age more than30years （POR=1.34,95%CI:1.16¹.55）, as a servics or sales （POR=1.20,95%CI:1.03¹.40）, education in10-12years （POR=1.11,95%CI:1.00¹.23）, hospitals whenfirst antenatal care was township （POR=1.43,95%CI:1.30¹.56）, overweight andobesity （POR=1.36,95%CI:1.17¹.58）, parity （POR=2.49,95%CI:2.04³.05）, historyof habitual abortion （POR=1.46,95%CI:1.27¹.68）, history of induced abortion（POR=1.22,95%CI:1.13¹.33）, male fetus （POR=1.10,95%CI:1.01¹.19） wereincrease the risk of CDMR.Conclusion1. Overall prevalence of CS was41.7%among Kunshan City, Jiangsu Province.And it was in a downward trend in the study period, and the following5years were alsoin a downward trend.2. Maternal and fetal characteristcs were associated with the increased theprevalence of UCS and LCS as a whole.3. Higher level of GWG may increase the prevalence of CS, irrespective of LCS orUCS.4. Maternal and fetal characteristics were associated with increased the prevalenceof CDMR in a combined way.