[The application and significance in prenatal diagnosis using G-banding, fluorescence in situ hybridization and comparative genomic hybridization].

OBJECTIVE: To investigate the procedure and the value of G-banding, fluorescence in sit hybridization (FISH) and comparative genomic hybridization (CGH) techniques in prenatal diagnosis. METHODS: Karyotype analyses with three diagnostic procedures, G-banding, G-banding and FISH, G-banding, FISH and CGH, were performed in the amniotic fluid samples taken from 102 fetuses at gestational ages 16-24 weeks. And the significance was valued in prenatal diagnosis. RESULTS: In the first procedure of karyotype analysis, 98 cases were diagnosed, 2 cases were not conformed while 2 cases were failed in all 102 cases. In the second procedure, 2 cases were determined, 1 case was not conformed and 1 case was still failed. In the third step, 2 cases were diagnosed. The diagnostic rate of the karyotype reached to 100% (102/102 cases) using all the three procedures. In total, seven cases with chromosomal abnormality were diagnosed. Four cases, 1 case and 2 cases were identified in the first step (4/7, 57.1%), the second (1/7, 14.3%) and the third (2/7, 28.5%), respectively. CONCLUSION: It can help improve the diagnostic rate of chromosomal aberrations and standardize diagnostic procedure to perform the three detecting steps in prenatal diagnosis.

[Systematic continuous sequence approach in diagnosing fetal deformity].

OBJECTIVE: To explore the value of ultrasonographic evaluation in fetal deformity in prenatal diagnosis by a systematic continuous sequence approach (SCSA). METHODS: Successive prenatal ultrasonographic evaluation was performed to monitor the whole anatomic structure,form, posture and movement of 16,685 fetuses during gestation aging 14 approximately 40(+3) weeks. RESULTS: Satisfactory ultrasonic images were obtained in 16,627 fetuses using the SCSA (99.65%). Of them, 514 abnormal fetuses were confirmed after subsequent labor or induced labor and 498 abnormal fetuses were correctly diagnosed using SCSA during prenatal stage (96.89%). Whereas 16 fetuses missed recognition (3.11%). Its sensitivity, specificity, positive and negative predictive value of diagnosis on fetal deformity were 96.98%, 99.96%, 98.66%, and 99.90 %, respectively. CONCLUSION: SCSA in prenatal ultrasonographic evaluation of the fetal structure and malformation is reliable and accurate.

[Fetal posterior cranial fossa in the second and third trimester].

OBJECTIVE: To examine the normal range of the width of posterior cranial fossa (WPCF) in the second and third trimester by ultrasonography, and to investigate its relationship with fetal congenital and chromosome abnormality. METHODS: WPCF of 2484 fetus (gestational age from 14 to 41 weeks) was measured by ultrasonograph routinely, and the infants were followed up. RESULTS: In 2848 fetus, 2772 were normal and 76 were abnormal. WPCF increased before 32 weeks, decreased after 33 weeks, the largest value of WPCF was 13.4 mm. The occurrence rate of WPCF> or =8 mm in normal fetus was 8.84%, and that in abnormal fetus was 17.46%. Most fetuses with chromosome abnormality had normal WPCF in the second trimester, but some fetuses with remarkable broadening in the late stage. Some abnormal fetuses (such as water head, Dandy-Walker's syndrome etc) showed significant extension of WPCF. CONCLUSION: WPCF increases before 32 weeks, decreases after 33 weeks;and can be easily measured during 29 - 32 weeks. WPCF of some fetus with chromosome abnormality or with congenital abnormality is remarkably broadened in the late stage. The fetus of WPCF> or =10 mm should be followed up closely, and antenatal diagnosis should be done if WPCF is more than 14 mm.

[Diagnosis of ovarian teratomas with two-dimensional ultrasound].

OBJECTIVE: To investigate the value of two-dimensional ultrasound in the diagnosis of tertoma in the ovary. METHODS: The sonographic images of 278 cases of ovarian teratomas confirmed by surgical pathology were reviewed. RESULTS: According to the surgical pathological results of the 278 cases, 95.3% (265/278) were benign, and 4.7% (13/278) were malignant. Among those, 88.5% (246/278) cases were unilateral, and 11.5% (32/278) were bilateral. Compared with the surgical pathological results, the rate of accurate diagnosis with ultrasound was 95.0% (264/278), the rate of misdiagnosis was 3.6% (10/278), and the rate of missed diagnosis was 1.4% (4/278). Among the benign cases, the rate of accurate dingnosis was 95.1% (252/265); the rate of misdiagnosis was 3.4% (9/265); and the rate of missed diagnosis was 1.5% (4/265). Among the 13 malignant cases, the rate of accurate diagnosis and misdiagnosis were 92.3% (12/13) and 7.7% (1/13), respectively. CONCLUSION: Two-dimensional ultrasound can be the first choice in diagnosing teratoma. Although the sonographic images of ovarian teratoma have specialities, they should be differentiated from other ovarian tumors, such as chocolate cyst of ovary, denaturation of subserous myoma, inflammatory mass, and etc.