Placenta previa Diagnosis
Diagnosis:
The last 40 years, the diagnosis of placenta previa has been great progress, because of the clinical application of B-to make the diagnosis of placenta previa, so that patients can receive timely treatment.
1. A history of pregnancy, late or after labor has painless vaginal bleeding, especially repeated vaginal bleeding, if the amount of bleeding early while many are probably complete placenta previa
2. A small amount of bleeding in patients with initial signs may be a special performance of repeated bleeding or a substantial bleeding, anemia patients have severe bleeding can occur Maung shock; abdomen to check the high-floating fetal head or breech presentation; symphysis pubis can be heard on the placenta murmur.
3. Vaginal examination in the diagnosis of placenta previa evolution, B-has not yet been invented before, vaginal examinations are confirmed once an important method for placenta previa.
4. Ultrasonography since the advent of B-type ultrasonic inspection after inspection it quickly became the best way to placenta previa, easy, safe, accurate and noninvasive are its main features. More than 30 years, many scholars in the ultrasonic inspection of a lot of work to do, not only for placenta previa happened to do a beneficial exploration and ultrasound technology to enable better.
Repeated or a vaginal bleeding and shock may be complicated by anemia. Excessive bleeding can intrauterine hypoxia, fetal heart rate changes have serious cases of intrauterine fetal death.
Differential Diagnosis:
1. Placental abruption severe placental abruption showed the continuity of sudden abdominal pain, lumbar acid, low back pain without vaginal bleeding or a small amount of vaginal bleeding, anemia and go out to the extent inconsistent with blood, uterine hardware such as plate, but the light of Sometimes placental abruption and placenta previa similar clinical manifestations, B ultrasonic examination can be found in the placenta after the hematoma, confirmed the diagnosis of placental abruption has Value.
2. Cervical polyps cervical examination when there is tongue see extraoral cervical prominence, the easy touch bleeding, biopsy-confirmed cervical polyp can be.
3. Cervical pregnancy associated with the disease in low incidence of cervical examination when the cervix was found on cauliflower-like supernumerary
Objects touch of easy bleeding can be diagnosed biopsy.
Laboratory examinations:
Choose the condition of patients to do routine blood test, a blood coagulation, such as inspection.
Other auxiliary examinations:
1. Ultrasonography at home and abroad in recent years the field of obstetrics and gynecology has been widely used B-mode ultrasound examination of the placenta positioning accuracy up to 95% by B-mode ultrasonography can clearly see the uterine wall, the Ministry of fetal presentation, placental and cervical position, and in accordance with the edge of the placenta and the relationship between the mouth of the cervix in placenta praevia further clarify the type of its simple, safe, reliable, non-invasive, and can therefore duplicate check has been replaced by a radionuclide scan positioning, imaging and other indirect placenta Ways.
B-mode ultrasound diagnosis of placenta previa to be careful in a few weeks of pregnancy. Second trimester placenta to occupy half of the palace wall area of the placenta, therefore close to or covering the mouth of the cervix with more opportunities; third trimester placenta occupied palace wall area reduced to 1 / 3 or 1 / 4. Formation and lower uterine segment increased by stretching the cervix within the mouth and the distance between the edge of the placenta, so that at lower segment of the placenta can be moved up with the Palace to change the location of the placenta normal. Many scholars think so, if the second trimester ultrasound examination revealed B-type pre-placental, and should not be diagnosed as placenta previa, the placenta should be said that pre-status
Application of B-mode ultrasound diagnosis of placenta previa happen, misdiagnosis causes and possible methods to avoid.
(1) false positive: ① overactive bladder filling, the cervix was elongated lower segment shift pressure to the rear, so that the uterus close to each other and constitute a similar Sonographic placenta previa, at this time should be part of bladder emptying after the check; ② the limitations of lower uterine segment contraction, the site of uterine muscle wall thickening, or uplift, the local echo enhanced sonographic resembles its placenta, and should therefore be reviewed after uterine relaxation.
(2) false negative: more adverse to mother and infant should be avoided whenever possible. ① not filling the bladder; ② posterior placenta, the fetus because of the sound beam at some attenuation, the sound shadow tends to the posterior wall of the placenta can not develop at this time can be pushed up further scanning head. Secondly, the determination of fetal head and the distance between the sacral promontory, such as> 1.6cm should be highly suspected; ③ cervical internal os hematocele hematocele mouth within the fluid nature of the dark zone sometimes be mistaken for amniotic fluid nature of the dark zone, careful observation can be found in the dark area above the placenta rather than the echo will be able to identify fetal presentation. In addition, the mouth hematocele when there is activity is often accompanied by vaginal bleeding, but also contribute to the diagnosis.
B-mode ultrasonography with vaginal examination the cervix can be clearly identified within the mouth and the relationship between the placenta, and its accuracy rate of almost 100 percent can reduce the abdominal ultrasonography B-existence of false-positive rate or false negative rate. Operation should be gentle, to avoid bleeding and the prevention of infection.
2. Magnetic resonance imaging also no harm to check for placental abnormalities such as placenta previa, etc. One of the ways. However, the method of checking the steps more complex than the expensive, it can not be replaced by B-.
3. Cystography contrast agent and radionuclide scanning Method cystography contrast agent embedded with the placenta between the fetal head and bladder so that the mechanism for the larger intervals of bladder filling in the X-ray after the upright position for pregnant women to do is, lateral imaging , whichever is more than 2cm spacing to diagnose placenta previa, but the accuracy of this method is not high breech does not apply, and the radiation of the mother, children do not have damage to it now. Radionuclide 113mIn (113m indium) was used to check the placenta previa, but the accuracy of the difference between types of placenta previa are not as good as B ultrasonic examination method and the need for special equipment, it has been replaced as the B-.
4. Postpartum check placenta and fetal membranes form the placenta after childbirth, generally larger, thinner, and sometimes arranged circular or irregular in shape there is a small number of vice placenta. Front part of the placenta is often accompanied by dark brown old blood clot, fetal membranes and placenta Break the edge of the edge of the vertical distance at less than 7cm can be diagnosed as a low placenta home.
Related inspections:
> Obstetrics and Gynecology Ultrasonography