Women's preference of delivery mode and cesarean section rate in the background of China's two-child policy in Hohhot

Abstract

Background: Cesarean sections are associated with short and long term risks for mothers, babies and also further pregnancies. China has the highest rate of cesarean section. After the two-child policy was adopted in 2016, nearly 60 percent of the women now eligible are age 35 or older. If a woman's first child was delivered via C-section, the mother faces greater risk when having a second. Such situation may increase the overall CS rate after the policy. However, the second-child policy may make women consider the harms associated with C-sections more carefully, especially among nulliparous who can have a second child. It may provide an opportunity to see a decline in the rate of CS. In addition, many studies have been documented that the women's preference of CS is an important factor associated the high rate. Finally, to our knowledge, there were few study focusing on the influence of the two-child policy on CS rate and women's preference on the mode of delivery. Objectives: 1) to explored women's preference for delivery mode and its influencing factors, particularly for non-medical factors, in the background of China's two-child policy; 2) to explore the change of CS rate with the development of two-child policy. Methodology: Part 1 - a hospital-based cross-sectional study for the first objective. This hospital-based cross-sectional study was conducted from December 2016 to January 2017 in Hohhot, China. Eligible participants were pregnant women: 1) attending prenatal care during the period of data collection, and 2) gestational age ≥ 28 weeks. Exclusion criteria: 1) women with a history of previous CS and other uterus surgery were excluded; 2) women with self-reported severe disease in previous seven days and women with diagnosed complications. Participants were consecutively recruited into this study in during data collection and were classified into three groups by delivery mode preference; vaginal birth (VB), CS, and "no clear preference". We identified the influencing factors of women's choices by multinomial logistic regression. The adjusted relative-risk ratios (aRRR) for the factors affecting the preference for CS and "no clear preference" categories and their 95% CI were computed, using the preference for VB as the reference group. Part 2 - a retrospective study for the second objective. This study was conducted in one of the four public tertiary hospitals sampled in the cross-sectional study. Data were retrieved from women's electronic medical records of hospital information system (HIS). We collected obstetric care data of woman who was 1): admitted for childbirth between January of 2012 to the end of 2017; 2) gestational weeks >28; and 3) maternal age ≥18 years old. Women meeting with following criteria were excluded: 1) missing data on the mode of delivery, 2) fetal weigh <1.0 kg. A modified Robson 10-group classification system was used to categorize women into different risk groups. Chi-square tests were used to calculate differences within three periods. To assess the association between time period and delivery mode, we performed binomial logistic regression. The outcome variable was delivery mode (CS versus VB), the primary predictor was time period (Period I: 2012-2013, one-child policy time; Period II: 2014-2015, only-child policy time; and Period III: 2016-2017, two-child policy time), controlling by other predictors including women's demographics, maternal obstetric characteristics. Results: Part 1- VB was preferred by 80.3% of the subjects, 8.8% preferred CS and 10.9% had not decided yet. In the multinomial logistic regression, pregnant women intending to have more than one child were less likely to prefer CS (aRRR:0.37; 95% CI: 0.22-0.61); choosing a lucky day for baby birth was the strongest factor for CS preference (aRRR 12.36; 95% CI 6.62-23.08), other factors for CS preference were aged 40 and above (aRRR 4.21; 95% CI 1.43-12.40), being ethnic minority (aRRR 2.00 (95% CI 1.17, 3.41)), feeling difficult in getting pregnant (aRRR 2.23; 95% CI 1.20, 4.13), and having husband's preference for CS (aRRR 7.62; 95% CI 4.00-14.54). The top reasons for preferring CS were the belief that CS was safer (51.5%), less pain (40.8%), and better for baby's and woman's health (24.3% and 22.3%). Part 2 - a total of 25088 eligible women were analyzed, including 16159 (64.4%) nulliparous and 8929 (35.6%) multiparous. 11097 (44.2%) of women delivered baby via CS from 2012 to 2017. The overall CS rate declined from 45.2 in 2012 to 37.8% in 2017, and peaked at 53.4% in 2014. While the CS rate among multiparous increased from 40.9% to 61.3%. The nulliparous women with a single cephalic and at 37>= gestational weeks (group 2) made the largest absolute contribution (20.7%) for the overall CS rate. The absolute contribution of the multiparous with previous CS scar (group 5) was increasing from 6.3% in period I to 12.1% in period III. Women giving birth in period II and period III were less likely to undergo cesarean deliveries than those in period I with the aOR 0.64 (95% CI 0.55 -0.74) and aOR 0.31 (95% CI 0.27 -0.35) respectively. Women aged 40 and above were around 2 times more likely to take CS, compared with those aged under 30 (aOR: 2.40; 95% CI 1.86 - 3.10). The ethnicity was also associated with mode of delivery. Compared with Han, ethnic minority women were more likely to give birth by CS (aOR: 1.37; 95% CI 1.21-1.54). Conclusions: Less than one-tenth of the study subjects preferred CS. The cultural beliefs had the strongest influence on the decision of delivery mode. Those intending to have two or more children following the two-child policy were less likely to choose CS. The overall CS rate has started to decrease since the relaxation of one- child policy in 2014, while the contribution made by the multiparous with previous uterus scar has increased after the two-child policy implemented.