Accurate prenatal discrimination between a simple, non-adherent uterine scar dehiscence with an underlying placenta and the severe end of the placenta accreta spectrum is problematic as the two can appear similar on prenatal imaging. This may lead to the false diagnosis of placenta accreta spectrum resulting obstetric anxiety, overtreatment and potential iatrogenic morbidity. Despite potential similarities in the etiology, the manifestation and management of these two conditions is very different. The prenatal sonographic features of seven confirmed cases of simple uterine scar dehiscence with an underlying placenta previa were examined. The common sonographic features found for scar dehiscence was a thinned myometrium (<1 mm) overlying a generally homogenous placenta and a placental bulge. There was absence of lacunae and features of hypervascularity including bridging vessels. Our findings suggest accurate discrimination between a simple scar dehiscence with the placenta underlying it and placenta accreta spectrum can be made on prenatal ultrasound if the placenta is carefully examined for the vascular features unique to PAS.

BACKGROUND: Clinically silent uterine rupture with complete fetal expulsion into the abdominal cavity is an extremely rare complication. Diagnosis can be difficult and the risk to the mother and fetus is high. Conservative management has been described only in a few cases of partial expulsion of the fetus so far.
METHODS: We present a case of 43-year-old tercigravida with a history of previous laparotomic myomectomy and subsequent cesarean section. The subsequent pregnancy was complicated by uterine wall loosening and rupture at the site of the previous uterine scar after myomectomy and complete fetal expulsion into the abdominal cavity. The diagnosis was made at 24 + 6 weeks of gestation. Considering the absence of clinical symptomatology and the good condition of the fetus, a conservative approach was chosen with intensive monitoring of the maternal and fetal conditions. The pregnancy ended by elective cesarean section and hysterectomy at 28 + 0 weeks of gestation. The postpartum course was uneventful and the newborn was discharged to home care 63 days after delivery.
CONCLUSIONS: Fetal expulsion into the abdominal cavity after silent uterine rupture of the scarred uterus may be accompanied by minimal symptomatology making early diagnosis difficult. This rare complication must be considered in the differential diagnosis in women after major uterine surgery. In selected cases and under conditions of intensive maternal and fetal monitoring, conservative management may be chosen to reduce the risks associated with prematurity.

Uterine rupture is a rare life-threatening complication. It can occur in all 3 trimesters with the first and the second being a rarity. It mainly occurs in the third trimester or during labor in a previously scarred uterus. It is rare in an unscarred uterus. The risk fold is further enhanced by the induction and augmentation with prostaglandins and oxytocin. The clinical diagnosis at this early gestation can be a dilemma to the attending physician as in this case. (1) The patient was a holidaymaker with no documented evidence of a dating scan to suggest any evidence of an ovarian/placental pathology at that stage. (2) The ultrasound findings in our department did suggest a viable intrauterine pregnancy with free fluid within both the adnexa. A 6 cm solid homogenous mass in the midline/right adnexa suggested an ovarian torsion or bowel pathology. The differentials in this particular case were that of a ruptured hemorrhagic cyst, ovarian torsion and even a heterotrophic pregnancy as there had been a few documented cases in the department. Ultrasound diagnosis of an intrauterine pregnancy together with a fluid collection does not suggest by any means that the uterus is intact or there is no ectopic pregnancy.