Placenta Previa – Term Paper

Abstract

The paper discussion is about Placenta Previa a medical condition observed, and that occurs in women during birth. The paper begins b giving an introduction of the term Placenta Previa sampling the data survey together with the degree of the disease. The paper further presents a credible discussion on the pathology discussing some of the causes and risks. Diagnosis is also looked it with the article pointing out some of the significant procedures and care taken to help in prevention and treatment of Placenta Previa. Prognosis and management outline some of the primary managerial procedures to be taken and observed to prevent and help one with Placenta Previa. Finally, the paper gives a conclusion of the recap of all the discussion in the article. Introduction

Placenta Previa is a condition in which the placenta implants in the lower portion of the uterus and covers all or part of the internal cervical os. The incidence according to the survey is that 1 out of 200 women giving birth. The major difficulty with classification system is accounting for the potentially changing relationship between the placenta and cervix during the third trimester, especially as labor progresses (Nyberg, 2003). Degrees of Placenta Previa are described concerning the internal os prior or the onset of labor. There are four types or degree of Placenta Previa:

 Total Placenta Previa is where the internal os is entirely covered by the placenta

 Marginal Placenta Previa is whereby the edging of the placenta is close to the internal os.

 Partial Placenta Previa is where the internal os is partly sheltered by the placenta.

 Low lying Placenta Previa is where lower uterine segment has a placenta implant such that the placental edging has a proximity of the internal os.

The incidence of Placenta Previa varies widely with gestational age at diagnosis and the criteria used. The impact at the term of clinically significant Placenta Previa is approximately 0.5% (Nyberg, 2003). Placenta Previa is diagnosed in about 5% of second-trimester pregnancies before genetic amniocentesis. At least 90% of Placenta Previa, therefore, resolves to a standard position by the term. Possible reasons for this improvement are discussed in the following pathology section.

Pathology

Placenta Previa results from implantation of the blastocyst in the lower uterine segment. Some factors appear to increase the risk of this occurrence, including advancing age, multi-parity, smoking, cocaine use, prior Placenta Previa and parity, previous cesarean delivery and suction curettage related to pregnancy. The firm association between Placenta Previa and parity previous cesarean delivery and curettage suggests that endometrial damage is an etiologic factor. Subsequent pregnancies are more likely to implant in the lower uterine segment by a process of elimination (Mishell, Goodwin & Brenner, 2002). Multiple pregnancies are at higher risk because of the reduced surface area of the endometrial available.

Improvement in Placenta Previa with gestational age primarily reflects marketed growth of the lower uterine segment during pregnancy which pulls the placenta superiorly. At 20 weeks, the placenta covers approximately one-fourth of the myometrium surface area, but near term the placenta covers one-eighth the myometrial surface. Improvement may also be partly secondary to trophotropism in which the placenta atrophies at suboptimal sites of implantation and hypertrophies at more optimal sites.

Diagnosis

Placenta Previa is most often diagnosed by routine sonography. In other cases, the initial diagnosis is made at the time of presentation for vaginal bleeding through the second part of pregnancy. In these cases, sonographic confirmation of placental location is recommended before the digital cervical examination. The trans-abdominal ultrasound may confirm the suspicion of Placental Previa (Krishna, Daftary & Tank, 1995). When sufficient visualization of the affiliation between the placenta and the internal cervical os is not possible with trans-abdominal ultrasound, the transperineal or transvaginal approach may be beneficial. Careful transvaginal may be beneficial. Careful sonography does not appear to increase the risk of hemorrhage in Placenta Previa.

In general, prenatal ultrasound is highly sensitive but not specific for the diagnosis of placenta previa. Therefore, while false negative diagnoses are rare, false positive diagnoses are common depending on the gestational age, the sonographic technique used. This is especially true before the third trimester because of differential growth of the lower segment of the uterus in the second half of pregnancy.

Placental Previa is readily diagnosed by the location of the placenta over the cervix. Placenta localization by trans-vaginal examination complements trans-abdominal scans and provides good visualization of the internal os and its relationship to the location of the placenta. Thus, may help to decrease the number of false positive diagnosed with Placenta Previa during early pregnancy (Nyberg, 2003).

Prognosis and management

Krishna, Daftary and Tank (1995) indicate that patients with a lower lying identify at mid-trimester should be observed with further ultrasound examination until at least 34 weeks, or unequivocal conversion has occurred. Placenta Previa diagnosed by custom second-trimester sonography is managed expectancy. The patient can be a measure that the likelihood of spontaneous resolution is greater than 90%. It is reasonable to recommend avoidance of strenuous activity, but further limitations probably are not necessary early in pregnancy. The placental location should be re-evaluated at 28-30 weeks (Mishell, Goodwin & Brenner, 2002). If Placenta Previa persists, the patient should be cautioned that rigorous activity and intercourse might provoke bleeding. Cesarean delivery should be scheduled at a gestational age that will exploit the probability of fetal maturity and diminish the risk of hemorrhage that may effect from the standard commencement of uterine abbreviations.

According to Mishell, Goodwin and Brenner (2002) the management of Placenta Previa complicated by acute hemorrhage is directed at optimizing the outcomes of the mother and the fetus. In many cases, bleeding resolves spontaneously and the patient may be managed expectantly. In other cases, severe hemorrhage may require intervention. The management varies dramatically with the severity of the condition. Through ultrasound with color and duplex Doppler should be performed. MRI should be considered.

Mild cases of placenta accrete may be treated with hemostatic cultures and removal of the placenta or observation alone. Patients may also be treated with methotrexate (Nyberg, 2003). For more classic, severe cases the usual treatment is hysterectomy at the time of delivery. If the placenta also invades the urinary bladder, however, this may be insufficient to control the hemorrhage. Adequate blood for transfusion must be available at the time of delivery. The goal is to deliver a live, healthy baby and maintain the health of the mother.

Conclusion

In concluding Placenta Previa is a stipulation whereby the placenta implants in the lower portion of the uterus and covers all or part of the internal cervical. Degrees of Placenta Previa are described concerning the internal os prior or the onset of labor. It results from implantation of the blastocyst in the lower uterine segment. Some factors appear to increase the risk of this occurrence, including advancing age, multi-parity, smoking, cocaine use, prior Placenta Previa and parity, previous cesarean delivery and suction curettage related to pregnancy. Placental Previa is readily diagnosed by the location of the placenta over the cervix. Placenta localization by trans-vaginal examination complements trans-abdominal scans and provides good visualization of the internal os and its relationship to the location of the placenta. the management of Placenta Previa complicated by acute hemorrhage is directed at optimizing the outcomes of the mother and the fetus.

References

Krishna, U., Daftary, S., & Tank, D. K. (1995). Pregnancy at risk: Current concepts. New Delhi,

India: Jaypee Bros. Medical Publishers.

Mishell, D. R., Goodwin, T. M., & Brenner, P. F. (2002). Management of common problems in

           obstetrics and gynecology. Malden, Mass., USA: Blackwell.

Nyberg, D. A. (2003). Diagnostic imaging of fetal anomalies. Philadelphia: Lippincott Williams

& Wilkins.