Evaluation of the practical applications of fluorescence in situ hybridization in the prenatal diagnosis of positive noninvasive prenatal screenings.

OBJECTIVE: To investigate the application value and limitations of fluorescence in situ hybridization (FISH) in prenatal diagnosis of positive results for trisomies 13, 18, 21 (T13, T18, T21) and sex chromosome aneuploidies (SCAs) indicated by noninvasive prenatal screening (NIPS). METHODS: Samples from women who underwent prenatal diagnosis for the indication of positive NIPS of T13, T18, T21, and SCAs were collected. Each sample was split into two for both karyotype analysis and FISH analysis. The efficiency and consistency of FISH were assessed for the detection of chromosome abnormalities in the indications of positive NIPS results compared with karyotyping. RESULTS: A total of 649 pregnant women who scored positive for clinical significance of fetal chromosome abnormalities by NIPS were enrolled in our study, including T 13 (6%), T18 (14.3%), T21 (44.7%), SCAs (35.0%). From the following diagnostic test, the positive predictive value (PPV) of NIPS for T13, T18, T21, and SCAs was 17.9, 60.2, 89.3, and 43.6% respectively. FISH analysis was successful in all samples. Compared with karyotyping, the sensitivity and specificity were 98.3 and 100%, respectively. 95.7% (621/649) were fully concordant with karyotyping. 3.2% (21/649) cases were incompletely concordant with the karyotyping, among these cases, the FISH analysis identified all the aneuploidies, but karyotyping analysis provided more information about the chromosomal structure. There were 7 cases (1.1%, 7/649) of anomalies diagnosed by karyotype but missed out by FISH, all of which occurred in cases with the indication of SCAs. If the indications were confined to cases with a positive NIPS of T13, T18, T21, the diagnostic consistency of the two methods almost perfectly agree, and all the aneuploidies were detected by the FISH assay. FISH analysis was highly consistent in determining whether the fetus was euploid or not in the prenatal diagnosis for the patients with positive NIPS results compared with karyotyping (kappa= 0.976, p < .01). CONCLUSION: For the prenatal diagnostic indications of positive NIPS of T13, T18, T21, and SCAs, FISH was equally efficacious in identifying aneuploidies and provided a quick diagnosis to alleviate anxiety. However, the missed risk of FISH analysis for structural chromosomal abnormalities should be taken seriously and fully informed during genetic counseling.

Hysteroscopic morcellation for removal of persistent placental remnants in the uterine cornu: Two case reports.

RATIONALE: Hysteroscopic morcellation is an alternative approach for the removal of placental remnants, given its advantages of safety, efficiency and good reproductive outcomes. This superiority can be even more obvious for removing persistent placental remnants in the lateral angle of the uterine cavity after repeated dilation and curettage (D&C) of an angular pregnancy, which is rarely reported. PATIENT CONCERNS: Two patients who were both initially misdiagnosed as having missed intrauterine miscarriages underwent repeated suction-assisted D&C procedures and were found to have persistent placental remnants in the lateral angles of the uterine cavity. DIAGNOSES: Ultrasound and hysteroscopy evaluations showed that placental remnants in both cases were in the lateral uterine angles and protruding to the interstitial myometrium around the fallopian tube. We corrected the diagnosis to that of angular pregnancy according to a comprehensive consideration of the ultrasound, hysteroscopy and pathology results. INTERVENTIONS: We performed MyoSure hysteroscopic morcellation for both patients and the placental remnants were removed completely without any complication. OUTCOMES: The patients were both scheduled for a second-look hysteroscopy 1 to 3 months after surgery, which revealed normal morphology of the uterine cavities and tubal ostia. The patients both achieved normal intrauterine pregnancies several months after surgery. LESSONS: Hysteroscopic morcellation is a good alternative approach for the removal of placental remnants and should be considered in cases in which there might be a high risk of incomplete evacuation or a high risk of uterine perforation, especially in cases of angular pregnancy.