初步建立产后短期内（42~60 d）腹直肌间距的医学参考值范围，为产后腹直肌治疗给出建议。

纳入2019年8月至2020年8月南京医科大学附属苏州医院产后42~60 d门诊回访产妇126名，超声测量产后42~60 d经产妇的腹直肌间距，测量位置为腹中线脐上缘、脐上3 cm、脐上5 cm和脐下3 cm处，测量体位包含平卧位、屈卧位和站立位。采用两独立样本秩和检验比较经阴道分娩组与剖宫产分娩组、第一胎与非第一胎组在不同体位的不同脐水平时腹直肌间距的差异，并以第20百分位数和第80百分位数定义腹直肌间距的参考值范围。

产后42~60 d，经阴道分娩组（89例）和剖宫产组（37例）所有位点腹直肌间距的差异均具有统计学意义（P均＜0.05），第一胎组（72例）和非第一胎组（54例）所有位点腹直肌间距的差异均无统计学意义（P均＞0.05）。以产后腹直肌间距第20~第80百分位数定义参考值范围，经阴道分娩组在平卧位4个测量点依次为：19.60~38.30 mm、15.10~28.80 mm、11.00~21.50 mm、2.70~15.50 mm；在屈卧位4个测量点依次为：16.70~30.90 mm、12.90~26.30 mm、9.20~19.90 mm、1.90~12.00 mm；站立位4个测量点依次为：19.00~39.10、15.90~35.50、11.20~28.50、0.00~8.60。剖宫产组平卧位4个测量点依次为：25.92~44.04 mm、19.78~32.44 mm、14.94~28.76 mm、7.78~24.88 mm；在屈卧位4个测量点依次为：20.12~36.68 mm、17.20~28.44 mm、13.38~26.24 mm、4.08~18.62 mm；站立位4个测量点依次为：28.80~45.68 mm、21.18~40.38 mm、18.04~33.70 mm、0.00~18.62 mm。

鉴于超声测量时屈卧位腹直肌边缘最易识别，在产后40~60 d时屈卧位腹中线最大腹直肌间距超过30.90 mm（经阴道分娩）、36.68 mm（剖宫产分娩）时表明产妇的腹直肌间距已经超过80%的产妇，建议接受进一步的治疗或康复手段。

To evaluate the normal range of inter-recti distance (IRD) 42-60 days postpartum, and then make the preliminary decision when the treatment for postnatal diastasis recti abdominis should be given.

A total of 126 women at 42-60 days postpartum were continuously collected to perform transabdominal sonography from August 2019 to August 2020 at the Affiliated Suzhou Hospital of Nanjing Medical University. IRD measurements were made at the upper margin of the umbilicus, 3 cm above the umbilicus, 5 cm above the umbilicus, and 3 cm below the umbilicus in the supine, flexion, and standing positions. Two independent sample rank-sum tests were used to compare differences in rectus ventral spacing at different umbilical levels between the transvaginal delivery and cesarean delivery and between first and non-first birth groups. The 20th and 80th percentiles were used to define the reference range of postpartum IRD.

The differences of IRDs between the vaginal delivery group (n=89) and the cesarean section group (n=89) were statistically significant (P＜0.05), but there were no significant differences in IRDs between the first (n=72) and non-first birth groups (n=54) (P＞0.05). The postpartum IRDs had a skewed distribution in the vaginal delivery group, with a percentile interval of 20%-80%; the IRDs at the four measurement points (3 cm above the umbilicus, 3 cm above the umbilicus, 5 cm above the umbilicus, and 3 cm below the umbilicus) in different positions were as follows: supine position (mm): 19.60-38.30, 15.10-28.80, 11.00-21.50, and 2.70-15.50; flexion position (mm):16.70-30.90, 12.90-26.30, 9.20-19.90, and 1.90-12.00; standing position (mm): 19.00-39.10, 15.90-35.50, 11.20-28.50, and 0.00-8.60, respectively. In the cesarean section group, there was a percentile interval of 20%-80%, and the IRDs at the four measurement points in different positions were: supine position (mm): 25.92-44.04, 19.78-32.44, 14.94-28.76, and 7.78-24.88; flexion position (mm): 20.12-36.68, 17.20-28.44, 13.38-26.24, and 4.08-18.62; standing position (mm): 28.80-45.68, 21.18-40.38, 18.04-33.70, and 0.00-18.62, respectively.

As the inner edge of the rectus abdominis is the easiest to be distinguished in the flexion position, it is suggested that the maximum space between the rectus abdominis in flexion position be more than 30.90 mm (vaginal delivery) and 36.68 mm (caesarean delivery), and when the measured value exceeds the postpartum IRD of 80% women, a treatment is suggested.