This is a little bit about placenta accreta that I would like to share with all of you. Hope it will be a good information.
Placenta accreta is a severe obstetric complication involving an abnormal superficial attachment of the placenta to the myometrium (the middle layer of theuterine wall). Usually placenta will attach to endometrium (inner layer of the uterine wall). There are three forms of placenta accreta, distinguishable by the depth of penetration.
Placenta accreta affects approximately 1 in 2,500 pregnancies.
The most common form of placenta accreta is an invasion of the myometrium which does not penetrate the entire thickness of the muscle. This form of the condition accounts for around 75-78% of all cases, and has no name other than placenta accreta.
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. Placenta increta occurs when the placenta further extends into the myometrium 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 myometrium to the uterine serosa (invades through entire uterine wall). This variant can lead to the placenta attaching to other organs such as the rectum or bladder.
The condition affects around 10% of cases of placenta previa (low-lying placenta), and is increased in incidence by the presence of scar tissue from a pastcaesarean section. A thin decidua can also be a contributing factor to such trophoblastic invasion. Some studies suggest that the rate of incidence is higher when the fetus is female.
In women with a history of one caesarian delivery, the incidence of placenta accreta may be as high as 30 percent. The risk increases with multiple caesarean deliveries and is also increased in women with history of uterine surgeries or maternal age over 35 years.
Placenta accreta is very rarely recognized before 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.
USG with Doppler can only diagnosed about 35% placenta accreta cases. The role of magnetic resonance imaging (MRI) in diagnosing placenta accreta has not yet been established.
The other way to make sure the diagnosed is with making microscopic slide from the uterine that had been removed. In this slide, you can see the trophoblasts cell will move to the myometrium.
Undiagnosed placenta accreta is associated with significant maternal morbidity and mortality up to 25%, due to intrapartum hemorrhage, uterine rupture, abscess formation, and bladder and rectum invasion.
- The myometrium is the middle layer of the uterine wall consisting of smooth muscle cells and supporting stromal and vascular tissue. The inner layer of the uterine wall is the endometrium or uterine lining, and the outer layer the serosa or perimetrium.
- Decidua is the term for the uterine lining (endometrium) during a pregnancy, which forms the maternal part of the placenta. It is formed under the influence ofprogesterone and forms highly-characteristic cells.
- Trophoblasts (from Greek threphein: to feed, and blastos: germinator) are cells forming the outer layer of a blastocyst, which provide nutrients to the embryoand develop into a large part of the placenta. They are formed during the first stage of pregnancy and are the first cells to differentiate from the fertilized egg. It differentiates into 2 cell layers, the inner layer called cytotrophoblast and outer layer called syncytiotrophoblasts.
- Placenta praevia (placenta previa AE) is an obstetric complication in which the placenta has attached to the uterine wall close to or covering the cervix . It can some times occur in the latter part of the first trimester, but usually during the second or third. It is a leading cause of antepartum haemorrhage (vaginalbleeding). It affects approximately 0.5% of all labours.
- Walling AD. Risk of hemorrhage and scarring in placenta accreta. American Family Physician. August 1999.
- Stolpen AH. Antepartum evaluation of suspected placenta accreta: is there a role for MRI? Proc. Intl. Soc. Mag. Reson. Med 9 (2001): p. 2082