Demographic and obstetric parameters of the analysed study population comparing women with and without 1st to 4th degree perineal tears.

* mean ± standard deviation.$ n (%).¤ median [25th percentile − 75th percentile]Demographic and obstetric parameters of the analysed study population comparing women with and without 1st to 4th degree perineal tears.* 均值±标准差（mean ± standard deviation）。例数（百分比）（n (%)）。¤ 中位数[第25百分位数－第75百分位数]（median [25th percentile − 75th percentile]）。本研究分析的受试人群的人口学与产科参数，用于对比存在1~4度会阴裂伤与无会阴裂伤的女性。