Pre-vascular Diagnosis

Diagnosis:

Application of color Doppler ultrasound (transvaginal) prenatal diagnosis can reduce the pre-vascular fetal mortality. Lee et al (2000) at 8 years of observation of 93,874 pregnant women with advanced cervical inside the mouth of Transabdominal gray-scale ultrasound imaging of the cervix within the vicinity I see there are parallel or surround the Echo Line are, by transvaginal color Doppler Ultrasonography proved to be pre-vascular. If the omission of prenatal, perinatal blood vessels after pre-identify the main points are:

1. Vagina inspection, through the expansion of the cervix, at the Ministry of fetal presentation on the pre-membrane palpable cord-like, there is pulsation of the artery.

2. When the production process occur when heart rate irregular, in the fetal membranes rupture before the membrane to do there is the diagnostic value of endoscopic examination.

3. Fetal membrane rupture, vaginal bleeding, associated with changes in fetal heart rate, irregular, or even disappear.

4. Check vaginal smears of blood, to find David has nucleated red blood cells or red blood cells. Immature, or is about to mature red blood cells only from fetal blood. Vagina check blood protein electrophoresis to do with fetal hemoglobin can also be found proved to be pre-vascular rupture

Differential Diagnosis:

Have to buy the placenta and low, Ⅰ degree of placental abruption and placenta ruptured marginal sinusoid phase identification. B ultrasonic examination can be the difference.

Laboratory examinations:

To determine if vaginal bleeding during pregnancy from the mother or the fetus is very difficult, many scholars in this regard and efforts to make the attempt, at present the basic methods are as follows:

1. Microscopic observation of the source of red blood cells generally observed to differentiate nucleated red blood cells have a source of bleeding, if there is more nucleated red blood cells, suggesting the possibility of fetal blood from the great, but this is not very characteristic way.

Test-tube home 2.ApT check blood Vagina 2 ~ 3ml, contour and add water to 2000r/min (r / min) centrifugation, collecting the supernatant add 1% NaOH, observation 2min, such as for the mother for color, such as for fetal blood, and will remain pink.

Test-tube 3.Ogita take home one dropwise Vagina 5 drops of blood alkaline liquid (0.1g weight KOH) shaking 2min, add 10 drops of pre-prepared solution (400ml of 50% saturated ammonium sulfate and 1ml of hydrochloric acid molecular weight 10g), which mixture to capillary drops on filter paper on to become a circle 20mm in diameter, in the 30s, such as for the degeneration of adult hemoglobin and cell debris is still at center, and anti-alkaline fetal hemoglobin to form a band at around the color circle.

Built-in vitro test 4.Loendersloot check 0.1g weight KOH 10ml, Vagina add a few drops of blood for the fetus such as blood, while in vitro is still pink, such as for the maternal blood, in the 20s within the color will change to brown.

5. Protein electrophoresis test of this law before it takes about 1h to Beckman hemolysis test agent to the vagina of blood diluted one-fold, and then hydrochloric acid maleic buffer 5 times and then diluted hemolytic substances electrophoresis, the sensitivity of this Act more high, but the equipment must have to take long.

First blood test 6.Kleihauser made blood smears, air dry 20min, and 80% ethanol fixed 5min to dry after washing gently flowing water, and then put lotion in the smear (FeCl3 14.8mmol / L and Hemastoxylin 16.5 mmol / L) 20s, again gently flowing water rinse, and then to ergthrosin 0.1g/100ml staining 2min, and then with water to clean dry microscope. Such as cells containing fetal hemoglobin (Hb-F) are stained red-brown for the obvious, such as for adult hemoglobin (Hb-A) while it appears as "Mirage."

Of the above methods, evaluate their strengths and weaknesses should be the basis of their sensitivity, specificity and the complexity of the experiment and reports to measure speed. Odansi et al (1996) has a list of the above methods are as follows:

Ogita the light of the above method is simple, fetal blood concentrations of up to 20% can be positive. Test time can only 5min, so unexplained vaginal bleeding, see too much red can be used to know whether there is pre-vascular. Reagents have to pay attention to tags, the replacement of one meeting per month to do the best test there is the positive control group in order to ensure its accuracy.

Other auxiliary examinations:

1. Gianopoulos ultrasonography in 1987 the first time, such as ultrasound scanning in the diagnosis of pre-vascular Example home for one low placenta cervix at the top of the suspect inside the mouth has a pair of placenta, blood vessels can be seen in this throb, so that the umbilical cord has probably exist, with Doppler ultrasound identified as fetal blood vessels, but several times to scan the location of the blood vessels suspected to be a fixed one, therefore pre-vascular, at 40 weeks of pregnancy when the selective cesarean section was live births 1 and confirmed that this is one Pre-vascular. Hurluy again in 1988 among antenatal ultrasound in pregnancy 18 weeks and 27 weeks pregnant when suspected vascular front, the two cases are double-leaf placenta, the first two cases there are repeated antenatal hemorrhage, two cases were 37 ~ 38 weeks pregnant, when to do cesarean section, each one live births inspection has confirmed its pre-placental blood vessels.

Nelson the first time in 1990 equal application of transvaginal ultrasound and Doppler ultrasound examination with the success of pre-vascular Nelson transvaginal sonography, such as think more clearly than the abdominal ultrasound, abdominal ultrasound can be difficult to display images, and and to determine its future relations with the population increasing number of such reports and confirmed that indeed for the diagnosis of an important means of pre-vascular.

In order to avoid pre-vascular fetal harm Lee equal in 2000 at a hospital report on 93,874 cases of pregnant women from January 1991 to December 1998 in the second trimester and third trimester of pregnancy to do the mouth of the cervix with ultrasonography, such as suspected to have abnormal blood vessels and transvaginal ultrasound and Doppler ultrasound to determine the diagnosis, the results have 18 cases of pregnant women have pre-vascular, the earliest found in Example 1 to 15.6 weeks. Example 8 shows that near the edge of the placenta inside the mouth and the last placenta "retreat" after the pre-vascular, Example 6 at an average 31.3 weeks when there is slight bleeding, 3 cases there is at third trimester, when B timeout to normal vaginal childbirth . The remaining 15 cases of termination of pregnancy by cesarean section, two cases of twins have a death, gestational age, only 1 Example 1 Example another 26 weeks because of premature infants with hyaline membrane disease and died of various diseases, such as 3 days postpartum. Examination showed 10 cases of placental umbilical cord has fan-shaped attachment, double-leaf three cases of placenta, the Deputy placenta Example 2, umbilical cord attached to two cases of marginal placenta, the report for a single hospital for nearly 10 years system checks the results and so it is representative.

According to Oyelese et al (1999) the actual experience, can be 20 weeks pregnant at the 1st B placenta overtime to do the positioning for the possibility of whether the provision of pre-vascular to all high-risk pregnant women, especially multiple pregnancy, low placental home, double leaf placenta and placenta from the Deputy has to do transvaginal ultrasound and Doppler examination, there is a world also includes the IVF-ET pregnancy.

Dougall and in accordance with pre-vascular Baind (1989) summed up the way they appear, as well as the recent development of vaginal and perineal ultrasound and color Doppler examination, it can be summed up as that is, six kinds: ① by ultrasound examination prior to the discovery of home blood vessels (not broken); ② palpable vaginal examination pre-vascular (unruptured); ③ membrane has not been broken and the pre-vascular rupture; ④ natural rupture of fetal membrane rupture when the pre-vascular; ⑤ when artificial rupture of membrane pre-vascular rupture; ⑥ front vascular compression

Prior to the use of ultrasonic diagnosis, often due to vaginal bleeding just to know there is placental lesions exist, but very easy to be misunderstood as placenta previa. Full-term pregnancy because of fetal blood volume of about 250ml of blood loss such as more than 20% ~ 25% which is equivalent to around 60ml hemorrhagic shock can happen without blood loss more timely treatment to the occurrence of fetal death is inevitable.

2. Magnetic resonance imaging MRI (magnetic resonance imagingMRI) also check the pre-vascular approach, high accuracy, Nimmo et al (1988) have been reported, but its high cost it is to use MRI diagnosis of the disease made it difficult to promote.

3. Amniotic endoscopic examination (amnioscopy) directly through the membrane mirror to see the fan-shaped blood vessels inside the mouth, after the cervix is a very reliable way, Browne et al (1968) have been 1434 cases of this method in pregnant women to do 3589 times membrane mirror examination revealed two cases of Pre-vascular but the method has its limitations Young et al (1991) method with the B-binding, identified two when using B-screening missed two pre-vascular patients. The author also consider pre-vascular easily appear in the double-leaf placenta or placenta there is vice, and low home placenta, fetal placenta many, IVF pregnancy, birth process in irregular bleeding or fetal heart rate and other circumstances, when at artificial rupture of membrane before the membrane to do mirror checks will help to find pre-vascular.