To explore the application value of ultrasonic measurement of the pubic symphysis distance in predicting pubic symphysis diastasis(PSD) during delivery.

A total of 262 pregnant women from June 2021 to July 2022 who delivered at Suzhou Wuzhong People′s Hospital and Jiangyin People′s Hospital were retrospectively analyzed. The patients were divided into PSD group of 26 cases and normal pregnant women group (control group) of 234 cases according to whether or not PSD was confirmed during postpartum follow-up. Relevant data of the two groups were collected, including the biparietal diameter and femoral length of the fetus within 7 days before delivery, the pubic symphysis distance of pregnant women when the cervix was not dilated, pubic symphysis distance when the cervix dilated to 5 cm during the first stage of delivery, and the pubic symphysis distance after delivery, the age of the pregnant woman, the gestational week, the number of pregnancies, and the birth weight of the fetus. The differences of the above relevant data between the two groups were compared.Spearman correlation analysis was used to analyze the correlation between various parameters. The occurrence of postpartum PSD, and Logistic regression was used to analyze the predictive value of various parameters on the occurrence of postpartum PSD. ROC curve was used to analyze the diagnostic efficacy of each parameters to predict PSD.

The fetal birth weight, number of pregnancies, pubic symphysis distance in three time points in the PSD group were significantly higher than those in the control group (all P<0.05). The age of the pregnant women was negatively correlated with the occurrence of postpartum PSD (r_s=-0.152, P=0.014). The fetal birth weight, the number of pregnancies, the pubic symphysis distance in the cervix no-dilated and the first stage of labor were positively correlated with the occurrence of postpartum PSD(r_s=0.160, 0.166, 0.678, 0.581, all P<0.05). Logistic regression analysis showed that the increase of pubic symphysis distance before labor would increase the risk of postpartum PSD, and the difference was statistically significant (OR=2 506.028, 95%CI=14.293-439 402.630, P=0.003). The increase of pubic symphysis distance at the first stage of labor increased the risk of postpartum PSD, with a statistically significant difference (OR=10 704.027, 95%CI=33.830-3 386 803.429, P=0.002). The ROC curve analysis showed that the area under the curve of the pubic symphysis distance in the cervix no-dilated and the first stage of labor for the diagnosis of PSD were 0.896 and 0.917 respectively, the sensitivity were 0.731 and 0.885, the specificity were 0.940 and 0.829, and the corresponding critical values were 0.87 cm and 1.06 cm respectively. The area under the curve of the combination of the two parameters for the diagnosis of PSD was 0.930, the sensitivity was 0.885, and the specificity was 0.876.

Ultrasonic measurement of pubic symphysis distance during delivery can predict the occurrence of postpartum PSD in pregnant women and can provide a basis for the occurrence and treatment of postpartum pubic symphysis separation in pregnant women.

Ultrasonography; Pubic symphysis diastasis; Pregnant women; Measurement