Parturition-Induced Pubic Diastasis

Anteroposterior view of the pelvis in a recently postpartum woman shows widening of the pubic symphysis > 1 cm (double-headed arrow).

Facts: Parturition-Induced Pubic Diastasis/Pelvic Dislocation

• There is increased mobility of pubic symphysis and sacroiliac joints during pregnancy because of hormonal change
• During delivery, a rapid forceful descent of fetal head against the pelvic ring can result in this injury
• Patients experience immediate pain and audible snap during labor
• Mostly require conservative treatment with a pelvic binder, lateral recumbency and analgesics. In few cases, surgical fixation is used.

Predisposing Factors

• Multiparity
• Forceps assisted delivery, shoulder dystocia
• Maternal developmental dysplasia of the hip, prior pelvic trauma

Imaging

• Separation of pubic symphysis >1 cm
• If separation >4 cm, usually associated with SI joint disruption
• Patients may have sacral fractures, lumbosacral plexus injury, bladder/urethral injury

Reference:

Kharrazi FD, Rodgers WB, Kennedy JG. Parturition-induced pelvic dislocation: a report of four cases. J Orthop Trauma 1997;11:277-281.