What is placental abruption and what are its clinical features?

Placental abruption is premature separation of a normally sited placenta. It is essentially a clinical diagnosis and is more a systemic than a local disorder.

Features: painful vaginal bleeding, a tender, contracted ('woody-hard') uterus, the presenting part often engaged, and bleeding that may be concealed or revealed. Maternal shock and fetal compromise may be out of proportion to visible loss.

Clinical relevance. Recognising the painful, woody-hard uterus and systemic complications distinguishes abruption from praevia and drives urgent management.

More Detail

Placental abruption

Abruption is premature placental separation, with systemic consequences beyond the local bleeding.

Definition

• Separation of a normally situated placenta before delivery; bleeding tracks from the chorio-decidual interface into the myometrium and serosa.
• More a systemic disorder than a local one - it causes coagulopathy (DIC), renal failure, higher fetal morbidity/mortality, and PPH.

Clinical features

• Painful vaginal bleeding (constant abdominal pain).
• Tender, contracted uterus ('woody-hard'), with uterine irritability.
• Presenting part often engaged (placenta normally sited).
• Concealed or revealed bleeding - in concealed abruption, blood is retained behind the placenta, so shock and fetal compromise may exceed visible loss.
• Couvelaire uterus - blood extravasates into the myometrium (a bruised, boggy uterus seen at caesarean).

Contrast with praevia

Abruption is painful with a tender, hard uterus; praevia is painless with a soft uterus and high head.