Analysis on the outcome of vaginal trial delivery in singleton full-term pregnancy with low-lying placenta

Abstract

Objective: To analyze the outcome of vaginal trial labor of pregnant women with low-lying placenta detected by translabial ultrasonography, and to explore the influencing factors of vaginal trial delivery and the risk factors of postpartum hemorrhage (PPH). Methods: A total of 80 pregnant women who were diagnosed by translabial ultrasonography with low-lying placenta and underwent vaginal trial delivery in Women's Hospital, School of Medicine Zhejiang University were collected. Based on the distance of placenta lower edge to cervical internal os (IOD) 1 cm, and the general characteristics and pregnancy outcomes of pregnant women with IOD≤1 cm and 1-2 cm were compared and the related factors of PPH were analyzed by binary logistic regression analysis. Results: Among the 80 pregnant women with low-lying placenta, 41 cases with IOD≤1 cm and 39 cases with IOD 1-2 cm, respectively. The rate of cesarean section in the two groups were 15% (6/41) and 15% (6/39), respectively. The birth weight of newborns were (3 334±360) and (3 460±365) g, respectively. PPH rates were 24% (10/41) and 26% (10/39), respectively, and the differences were not statistically significant (all P>0.05). Among the 80 pregnant women with low-lying placenta, 60 cases did not have PPH, and 20 cases did. The rates of placenta manual removal were 2% (1/60) and 20% (4/20), respectively. The birth weight of newborns were (3 330±368) and (3 591±284) g, respectively. The differences were statistically significant (all P<0.05). Binary logistic regression analysis suggested that placenta manual removal was a risk factor for PPH in pregnant women with low-lying placenta (OR=30.448, P=0.029). Conclusions: The results of vaginal trial labor in women with IOD≤1 cm and 1-2 cm are comparable, and vaginal trial labor could be attempted in those without contraindications of vaginal delivery. The main adverse complication of vaginal trial labor is PPH, and those with placenta manual removal need to make corresponding plans.