Placenta accreta

Placenta accreta is a severe obstetriccomplication involving an abnormal attachment of the placentato the myometrium(the middle layer of the uterine wall). There are three forms of placenta accreta, distinguishable by the depth of penetration.

The placenta usually detaches from the uterine wall relatively easily, but women that encounter placenta accreta during childbirthare at great risk of haemorrhageduring its removal. This commonly requires surgeryto stem the bleeding and fully remove the placenta, and in severe forms can often lead to a hysterectomyor be fatal.

Placenta accreta affects approximately 1 in 2,500 pregnancies.

Variants

The most common form of placenta accreta is an attachment onto the myometrium which does not penetrate the muscleitself. There are two further variants of the condition that are known by specific names and are defined by the depth of their attachment to uterine wall. However, this is the most common form of the condition and accounts for around 75–78% of all cases.

Placenta increta occurs when the placenta extends into the muscle of the uterine wall and happens in around 17% of all cases. Placenta percreta, the worst form of the condition and occurring in 5–7% of cases, is when the placenta penetrates the entire uterine wall. This variant can lead to the placenta attaching to other organs such as the bladder.

Diagnosis

Placenta accretia is very rarely recognised before the birth, and is very difficult to diagnose. While it can lead to some vaginal bleeding during the third trimester, this is more commonly associated with the factors leading to the condition. In some cases the second trimester can see elevated maternal serum alpha-fetoproteinlevels, though this is also an indicator of many other conditions.

Risk factors

The condition affects around 10% of cases of placenta praevia, and is increased in incidence by the presence of scar tissuefrom a past caesarean section. A thin deciduacan also be a contributing factor to such trophoblasticinvasion. Some studies suggest that the rate of incidence is higher when the fetusis female.

References

• Miller, David A. (2 November2004). Obstetric Hemorrhage, High Risk Pregnancy Directory at ObFocus. Accessed 25 January2006.
• (January 2004). Placenta Accretaat the American Pregnancy Association
• Mayes, M., Sweet, B. R. & Tiran, D. (1997). Mayes' Midwifery - A Textbook for Midwives 12th Edition, pp. 524, 709. Baillière Tindall. ISBN 0-7020-1757-4.

External links

• Placenta Accreta and Percreta: Sonographic, MRI, and Surgical Correlationat OBGYN.net
• Placenta Accretaat For Parents By Parents
• "Donors save mum's life" at The Herald Sun, 13 January2006.

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It uses material from the Wikipedia article Placenta accreta.