Asymptomatic rupture of the uterine scar – diagnosis during routine ultrasound check

Purpose: Asymptomatic ruptures of uterine scars after previous Caesarian Section (CS) are of utmost clinical importance even more so if a vaginal birth after CS (VBAC) is planned.

Ultrasound is commonly used in pregnancy and widely available. The routine measurement of the lower uterine segment (LUS) could help detecting patients who should by no means attempt a VBAC as our case suggests.

Case: A 38-year-old G4P3 was referred to our unit at 35 weeks and 2 days due to fetal renal pyelectasis seen in the second trimester ultrasound.

In all previous pregnancies the children were delivered by CS using a longitudinal incision in India.

Fig. 1: 3D scan: complete rupture of the uterine scar

The ultrasound showed a viable appropriately grown fetus in cephalic presentation showing a discrete bilateral pyelectasis. Our routine check of the uterine scar however, revealed an asymptomatic rupture of the anterior uterine wall with bulging of the amniotic membrane.

The patient was admitted for observation. Four days later she developed local pain close to the uterine scar associated with contractions of the uterus. The CS was performed and a healthy male baby was born weighing 2650 g.

The uterine scar showed a complete rupture with bulging amniotic membranes according to the sonographic findings measuring approximately 6 × 3 cm.

The patient recovered normally. Mother and baby could be discharged 5 days after CS.

Conclusion: Routine ultrasound which should include the measurement of the LUS after CS is able to provide reliable data which are important in risk management after CS.