我国计划妊娠女性妊娠间隔及其影响因素的横断面研究

A cross-sectional study of the interpregnancy intervals and its influence factors of women with planned pregnancies in China

目的:描述我国计划妊娠女性妊娠间隔(IPI)的分布现状及其影响因素。方法:选择2010年1月-2018年12月两次参加国家免费孕前优生健康检查项目的育龄女性作为研究对象。进行分析时IPI同时作为定量变量和定性变量,定性变量包括短IPI(<18个月)、适宜IPI(18~59个月)及长IPI(≥60个月)3组,以适宜IPI为对照。使用描述性流行病学方法研究IPI的分布,并采用广义线性回归模型和logistics回归模型探索IPI的影响因素并估计其关联强度指标β与比值比(OR)及其95%置信区间(CI)。结果:计划妊娠女性的IPI中位数为21.3个月,短IPI和长IPI分别占40.7%与1.6%。≥35岁者短IPI风险比20~24岁者降低87.0%(95%CI 86.0~88.0);相对于汉族、高中以下文化程度、正常体重及前次分娩无不良妊娠结局史者,少数民族、高中及以上文化程度、低体重与有不良妊娠结局史者短IPI风险分别增加21.0%(95%CI 16.0~26.0)、3.0%(95%CI 1.0~5.0)、5.0%(95%CI 2.0~9.0)与11.0%(95%CI 8.0~13.0);而与农村户籍、农民、正常体重、不饮酒及前次妊娠分娩方式为阴道分娩者相比,城市户籍、非农民、超重、饮酒及剖宫产者短IPI风险分别降低24.0%(95%CI 19.0~28.0)、11.0(95%CI 9.0%~16.0%)、8.0%(95%CI 6.0~10.0)、25.0%(95%CI 16.0~33.0)与53.0%(95%CI 52.0~55.0);与华北地区相比,其他各地区的短IPI风险均增加(P均<0.05)。结论:我国近50%的计划妊娠女性存在IPI过短或过长问题,未来应加强对有低龄、少数民族、高中及以上文化程度、低体重、农村户籍、农民、以及前次分娩为阴道分娩和发生不良妊娠结局等短IPI易发特征女性的宣传教育,帮助其选择适宜的IPI。

Objective:To describe the current distribution of the interpregnancy intervals(IPI)of women with planned pregnancies in China,and to identify its influencing factors.Methods:The women of reproductive age who participated in the national free pre-pregnancy checkups project twice between January 2010 and December 2018 were selected as the study population.When performing the analysis,IPI was used as both quantitative and qualitative variables,and the women were divided into three groups bases on the qualitative variables,which including the women with<18 months of short IPI in group A,the women with≥60 months of long IPI in group B and the women with 18-59 months of suitable IPI in the control group.Descriptive epidemiological methods were used to study the distribution of IPI of the women,and generalized linear regression models and logistic regression models were used to explore the factors influencing of IPI,and were used to estimate the indicatorβof the associative strength by odds ratio(OR)and its 95%confidence intervals(CI).Results:The median IPI of the women in this study was 21.3 months,40.7%of women had short IPI and 1.6%of women had long IPI.The risk of short IPI of those women aged≥35 years old had decreased by87.0%(95%CI 86.0-88.0)than those women aged 20-24 years old.Compared with those of the women with Han nationality,with lower than high school education level,with normal weight,or with history of adverse pregnancy outcomes in the previous delivery,the risk of short IPI of the women with ethnic minorities,with high school and above education level,with underweight,or with adverse pregnancy outcomes in the previous delivery had increased by21.0%(95%CI 16.0-26.0),3.0%(95%CI 1.0-5.0),5.0%(95%CI 2.0-9.0)or 11.0%(95%CI 8.0-13.0),respectively.Compared with those of the women with rural household registration,with farmer occupation,with normal weight,without drinking,or with vaginal delivery in the previous delivery,the risk of short IPI of the women with urban household registration,with other occupation out of farmer,with overweight,with alcohol consumption,or with cesarean section in the previous delivery had reduced by 24.0%(19.0-28.0),11.0%(95%CI 9.0-16.0),8.0%(95%CI 6.0-10.0),25.0%(95%CI 16.0-33.0)or 53.0%(95%CI 52.0-55.0),respectively.The risk of short IPI of the women from North China had significantly decreased than those women from the other regions of China(all P<0.05).Conclusion:Nearly half of the women with planned pregnancies in China experience either too short or too long IPI.In the future,the publicity and education should be strengthened for the women with short IPI susceptibility characteristics,such as low age,ethnic minorities,high school and above education level,underweight,rural householders,farmers,or experienced vaginal delivery or adverse pregnancy outcomes in the previous pregnancy,so as to help them to choose the appropriate IPI.