Parturition-induced pelvic instability

Parturition-induced pelvic instability is a rare condition seen in women following vaginal delivery.

Epidemiology

The incidence of symphyseal rupture after vaginal delivery ranges from one in 600 to one in 30,000 deliveries .

Predisposing factors include multiparity, complicated delivery, forceps or vacuum assisted delivery, shoulder dystocia, maternal hip dysplasia or prior pelvic trauma, hyperabduction of the thighs, and epidural anesthesia .

Pathology

Peripartum ligamentous relaxation with moderate widening of the pubic symphysis and sacroiliac joints is physiologic and occurs regularly. It is thought to be hormonally mediated by relaxin and progesterone . Physiologic peripartum symphyseal widening ranges from 3-7 mm and often remains asymptomatic. Slight pubic diastasis in the absence of clinical symptoms is frequent and does not necessitate medical treatment. After delivery, laxity of these ligaments gradually diminishes, the pubic diastalsis disappears, and pelvic stability is restored.

Treatment and prognosis

Treatment of postpartum symphyseal rupture has traditionally been non-operative and conservative . Bed rest, usually in a decubitus position, analgesics and the application of a pelvic binder to facilitate reduction of the diastalsis are sufficient to ensure full recovery in most case. The successful surgical treatment of the chronic postpartum pelvic pain usually is anterior pubic fixation with or without sacroiliac joint stabilization.

The occurrence of a symphyseal separation should not significantly alter the management of subsequent pregnancies, and conservative therapy is recommended for any recurrence of symptoms.