Abstract: Background　Physical activity is beneficial for women's health，such as improving the structure of pelvic floor mostly in non-pregnant populations.However，the physical activity pattern and its association with pelvic floor muscle remain to be explored in pregnant women.Objective　The aim of this study was to investigate the physical activity pattern and examine its association with levator ani muscle thickness （LA th） during pregnancy.Methods　A cross-sectional study was performed.Pregnant women in first and second trimesters receiving routine antenatal assessment from Shenzhen Hospital，Southern Medical University were enrolled from January to November 2017 by convenience sampling.Demographic and clinical information was collected through a self-administered questionnaire survey.The physical activity pattern was measured by Pregnancy Physical Activity Questionnaire.The LA th was examined by three-dimensional transperineal ultrasound.Multiple linear regression analyses were used to estimate the association between physical activity pattern and LA th with adjustment for the possible effects of confounding factors.Results　266 pregnant women participated in this study，of whom 10 were eliminated because of failing to complete the questionnaire.The final sample for analysis consisted of 256 effectively filled questionnaires.The M（P25，P75） of total energy expended on physical activity among them in first and second trimesters was 112.13（84.78，148.03） MET-h/wk.Multiple linear regression analyses showed that compared with first quartile group of energy expended on household activities，LA th at pelvic floor muscle contraction was stronger in fourth quartile group 〔β=0.699，95%CI（0.146，1.252）〕（P<0.05）.Compared with first quartile group of energy expended on moderate intensity activities，the difference between LA th at rest and at pelvic floor muscle contraction was higher in fourth quartile group 〔β=0.319，95%CI（0.117，0.522）〕（P<0.05）.Conclusion　These pregnant women in first and second trimesters did not have sufficient physical activity.Household activities and moderate intensity activities can increase LA th and improve the structure of pelvic floor muscle.Individualized care should be delivered to promote physical activity during pregnancy and improve the function of pelvic floor.

Key words: Pregnancy, Physical activity, Levator ani muscle, Pelvic floor

摘要： 背景　体力活动对女性健康具有重要意义，能够优化盆底肌结构，然而现有研究多针对非妊娠期人群，妊娠期女性体力活动模式如何尚不清楚，对盆底肌的影响仍有待探索。目的　调查妊娠期女性体力活动模式的现状，探讨体力活动模式与肛提肌厚度（LA th）的关系。方法　通过横断面研究，采用便利抽样法，选取2017年1—11月于南方医科大学深圳医院行常规产前检查的妊娠早中期女性为研究对象，通过自制的问卷进行一般资料的收集，采用中文版妊娠期体力活动问卷（PPAQ）评估妊娠期体力活动模式，采用经会阴盆底三维B超评估LA th，采用多元线性回归校正混杂因素效应，以分析体力活动模式与LA th的关系。结果　共266例孕妇参与调查，由于未填写完整问卷剔除10例，最终纳入256例有效样本。妊娠早中期女性的总体能量消耗为112.13（84.78，148.03）MET-h/wk。多元线性回归分析结果显示，家务活动能量消耗值第四分位（Q4）组缩肛状态下LA th〔LA th（C）〕大于第一分位（Q1）组〔β=0.699，95%CI（0.146，1.252）〕，中等强度活动Q4组静息状态与缩肛状态下LA th的差值〔LA th（D）〕大于Q1组〔β=0.319，95%CI（0.117，0.522）〕（P<0.05）。结论　妊娠早中期妇女的体力活动水平不足，家务活动和中等强度的体力活动可以增加LA th，优化盆底肌结构，应采取个体化干预措施，提升妊娠期体力活动水平，改善盆底健康。

关键词: 妊娠期, 体力活动, 肛提肌, 盆底