Placenta Accreta
Introduction
During pregnancy, the placenta is normally supposed to attach on the surface of uterine wall. There are instances when the placenta attaches itself so deeply on the uterine. Placenta accreta is an abnormal attachment of the placental villi to the uterine in which the placenta is attached unusually deeply into the uterine wall. In placenta accreta, the placenta is attached directly on the myometrium unlike in other variant accounts when it gets attached into the myometrium (hence the name placenta increta) or goes through the myometrium (hence the name placenta percreta). Apparently placenta accreta is the most common compared the placenta increta and placenta percreta accounting for over 75 per cent of the cases in which the placenta attaches deep into the uterine wall.
Prevalence
Kent (2009), while reviewing an article by Eller AG, Porter TF, Soisson P, Silver RM titles Optimal Management Strategies for Placenta Accreta, writes that the prevalence of placenta accreta is about 10 in every 10000 deliveries though higher rates are anticipated as the rates of cesarean deliveries keep on rising. As Resnik (n.d) echoes Kent (2009) assertion that there is a link between that higher incidence of cesarean and increased prevalence of placenta accreta when he says that prevalence of placenta accreta has been on a constant gradual increase owing to the increase in the number of cesarean deliveries being carried out. To prove his assertion, Resnik (n.d) refers to the prevalence of placenta accreta between the year 1950 and 1980. During the 1950s, placenta accreta was a rare complication with only 1 in 30000 deliveries being witnessed (Resnik, n.d). In the 1980s and 1990s, several incidences of placenta accreta were witness and scientist estimated the prevalence at 1 in every 2510 deliveries (Resnik, n.d). Resnik (n.d) further notes that at some point the prevalence of placenta accreta had been estimated at 1 in about 500. Also notable is the fact that placenta accreta is characteristically common in women with placenta previa; about 5 to 10 per cent of all the placenta accreta cases occur in women with placenta previa. Konijeti, Rajifer & Askari (2009), on their part, also concur with Kent (2009) and Resnik (n.d.) that the increase in the prevalence of placenta accreta can be traced to the increased cases of cesarean deliveries over the past few years. Konijeti, Rajifer & Askari (2009) estimate that the prevalence of placenta accreta is about 1 in every 2500; this significantly differs with the statistic given by Kent (2009) even though in comparison with the rates as seen in 1950s given Resnik (n.d.), Konijeti, Rajifer & Askari (2009) gives insight to the fact that more cases of placenta accreta are being witness with every turn of the year.
Causes of Placenta Accreta
The American Pregnancy Association attests that there is no known cause of placenta accreta. Konijeti, Rajifer & Askari (2009) are opinionated that even though the exact cause of placenta accreta in not clearly defined, there is a primitive link between placenta previa, cesarean delivery, grand multiparity as well as the Asherman syndrome and uterine curettage. Notably, Asherman syndrome is a case whereby the uterine wall is unusually scarred. Likewise, placenta previa is a condition in which the placenta is situated very low relative to the normal position in the uterus, and in some instances it might end up being attached on the cervix hence covering the cervix; a considerable number of women who get diagnosed with placenta previa always placenta accreta. Again, empirical research findings point to the fact that women with a history of cesarean deliveries, regardless of the number of deliveries one had in past, have higher chances of experiencing placenta accreta; this means that delivery though cesarean section has a causal effect in the causation of this complication that is commonly symptomatically manifested in the form of painless vagina bleeding and blood stains in the urine.
Diagnosis
Ultrasonography and Magnetic Resonance Imaging (MRI) are some of commonly employed methods of detecting placenta accreta. There are two common types of untrasonography that are always carried out during the diagnosis of Placenta accreta. The methods are Transvaginal and transabdominal ultrasonography. Transvaginal ultrasonography is utile in the examination of the lower portions on the uterine wall to detect irregularly shaped vascular spaces on the placenta, abnormal blood flow in the placenta, and increased numbers of vascular spaces on the placenta that are all suggestive of placenta accreta (ACOG, 2012). Transabdominal ultrasonography, on the other hand, is utilitarian in the visualization of the posterior sections of the placenta in search of ultrasonographic features similar to the ones observed using transvaginal ultrasonography (ACOG, 2012).
MRI, just like ultrasonography, also helps in observing the placenta for any anomalies although several physicians attest that it is more costly compared to ultrasonography besides requiring special skills that are not possessed by most physicians in most hospitals (ACOG, 2012). The only advantage that MRI has over ultrasonography is that it a relatively more accurate diagnostic method in the detection of placenta accreta compared to ultrasonography (ACOG, 2012).
Management of Placenta Accreta
There are various ways through which placenta accreta can be managed. With in mind that the diagnosis of placenta is essentially aimed at allowing planning for delivery, ACOG (2012) is opinionative that the delivery of patients diagnosed with placenta accreta should be individualized; the patient and the neonatologist together with the obstetrician should work closely to ensure that that patient has a successful and painless birth. Surgical approach is perhaps the most recommended treatment approach for placenta accreta in which the uterus is wholly removed (hysterectomy) with the placenta still attached to it. Any surgical attempt to remove the placenta is openly discouraged considering that the patient stands very high chances of bleeding excessively (hemorrhagic morbidity) (ACOG, 2012). Further, it bears to note that hysterectomy should only be performed on women with not future intention of bearing children (ACOG, 2012). Other management options for placenta accreta are the use of methotrexate ( an antimetabolite that limits the reproduction of cells) even though some research findings point out that trophoblast cells usually stop dividing after delivery which renders the antimetabolite useless, and balloon catheter occlusion that has no firm clinical evidence to support its usage even though it is believed to be an important procedure that can really better surgical management of placenta accreta (ACOG, 2012).
Conclusion
Concisely, placenta accreta is a condition in which the placenta is attached deeply into the uterine wall (on the myometrium). The cause of placenta accreta is not clearly known even though scientists believe that there is close relationship between the complication and cesarean deliveries together with placenta previa. Indubitably, this complication that is most commonly diagnosed through ultrasonography and MRI can be managed trhough various ways that are inclusive of surgery, use of methotrexate and individualized timely delivery.
References
American Congress of Obstetricians and Gynecologists (ACOG). (2012). ACOG - Placenta Accreta. American Congress of Obstetricians and Gynecologists . Retrieved November 19, 2012, from http://www.acog.org/Resources%20And%20Publications/Committee%20Opinions/Committee%20on%20Obstetric%20Practice/Placenta%20Accreta.aspx
American Pregnancy Association. (n.d.). Placenta Accreta. American Pregnancy Association. Retrieved November 19, 2012, from http://www.americanpregnancy.org/pregnancycomplications/placentaaccreta.html
Kent, A. (2009). Management of Placenta Accreta. National Center for Biotechnology Information. Retrieved November 19, 2012, from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2709317/
Resnik, R. (n.d.). Clinical features and diagnosis of placenta accreta, increta, and percreta. Walters Kluwer Health. Retrieved November 19, 2012, from http://www.uptodate.com/contents/clinical-features-and-diagnosis-of-placenta-accreta-increta-and-percreta
