Thin anterior uterine wall with incomplete uterine rupture in a primigravida detected by palpation and ultrasound: a case report

Abstract

IntroductionUterine rupture is an obstetric complication associated with significant maternal and fetal morbidity and mortality. This disorder usually occurs with a scarred uterus, especially in a uterus with prior Cesarean section. Uterine sacculation or diverticulum may also lead to a thin uterine wall during pregnancy.Case presentationA 27-year-old Japanese primigravid woman was admitted to our hospital due to weak, irregular uterine contractions in her 38th week of gestation. She had no past history of uterine surgery or known diseases. A hard mass was palpable in her abdomen. An ultrasound revealed that the anterior uterine wall was thin and bulging, with a fetal minor part beneath it which corresponded to the palpated mass. A Cesarean section was performed which revealed a thin anterior uterine wall with incomplete uterine rupture. The woman and baby were healthy.ConclusionsAlthough extremely rare, an unscarred primigravid uterus can undergo incomplete rupture even without discernable risk factors or labor pains. Abdominal palpation and ultrasound may be useful in detecting this condition.

Maternal and fetal morbidity associated with uterine rupture of the unscarred uterus

“…4 Cases with no identifiable risk factors, some even in the absence of labor, have also been described. [5][6][7][8][9][10][11][12][13] Primary uterine rupture occurring without labor is often preceded by a period of vague abdominal pain and nausea, followed by sudden, severe abdominal pain and fetal compromise. From these limited data, risk factors for primary uterine rupture have been proposed, and include malpresentation, oxytocin use, abnormal placentation, previous invasive mole, grand multiparity, prior midtrimester uterine instrumentation, uterine anomalies, macrosomia, and fetopelvic disproportion.…”

Sonographic diagnosis of spontaneous uterine rupture at the site of cornual wedge resection scar – a case report

“…Uterine rupture (also termed ‘complete rupture’) is a full‐thickness separation of the uterine wall and the overlying serosa, resulting in communication between the amniotic and abdominal cavities. It is associated with extensive bleeding, ruptured membranes, abdominal pain, fetal distress and expulsion of the fetus and/or placenta into the abdominal cavity 1 – 3 …”

“…Rupture is considered spontaneous if it occurs without contractile activity of the myometrium and is not the result of trauma such as violence, car accidents or manipulation 4 , 5 . Spontaneous rupture may rarely occur in unscarred uteri with adenomyosis, uterine or placental anomalies, infection, cephalopelvic disproportion or underlying connective tissue disease however most cases are associated with a scarred uterus, usually due to prior caesarean section 3 – 5 …”

“…Uterine dehiscence (also termed ‘incomplete rupture’) is a more common event than uterine rupture and is defined as the thinning or separation of a prior uterine scar which does not involve the uterine serosa or fetal membranes and is not associated with intra‐abdominal haemorrhage 2 , 3 , 6 …”

Pregnancy complicated by uterine sacculation due to a huge myoma

“…Uterine sacculation is a functional malformation of the pregnant uterus and occurs in about 1 in 3000 pregnancies 1–4 . Uterine sacculation is difficult to diagnose, but causes considerable intrapartum and postpartum morbidity in both mothers and infants 1,4,5 . Vaginal delivery should not be tried due to the risks of dystocia and uterine rupture 3,5 .…”