Transcervical recovery of fetal cells from the lower uterine pole: reliability of recovery and histological/immunocytochemical analysis of recovered cell populations.

The aim of this work was to isolate, enumerate and attempt the identification of fetal cells recovered from the lower uterine pole. Immediately before elective termination of pregnancy at 7-17 weeks gestation, samples were recovered by transcervical flushing of the lower uterine pole (n = 108) or transcervical aspiration of mucus from just above the internal os (n = 187), and their contents examined using histological, immunohistochemical and molecular techniques. Syncytiotrophoblasts were identified morphologically in 28 out of 89 (31%) and 50 out of 180 (28%) flushings and aspirates respectively (mean 29%). Immunocytochemistry with monoclonal antibodies (mAbs) recognizing trophoblast or epithelial cell antigens on a smaller number of samples (n = 69) identified putative placental cells in 13 out of 19 (68%) and 25 out of 50 (50%) flushings and aspirates respectively (mean 55%). These included groups of distinctive cells with a small, round, hyperchromatic nucleus, strongly reactive with mAbs PLAP, NDOG1 and FT1.41.1. Smaller groups of larger, amorphous cells, usually containing multiple large, pale staining nuclei, reactive with mAb 340 and to a lesser degree with mAb NDOG5 were also observed. Taking cellular morphology and immunophenotype into consideration, the smaller uninucleate cells were likely to be villous mesenchymal cells, while the larger cells were possibly degrading villous syncytiotrophoblast. There was no significant difference in the frequency of fetal cells obtained by the two recovery methods. Squamous or columnar epithelial cells, labelled strongly with antibodies to cytokeratins or human milk fat globule protein, were observed in 97% (29 out of 30) of aspirates. The use of cervagem in a small number of patients prior to termination of pregnancy did not appear to influence the subsequent recovery of placental cells. Y-specific DNA was detected by polymerase chain reaction (PCR) in 13 out of 26 (50%) flushings and (99 out of 154) 64% aspirates analysed (mean 62%). In-situ hybridization (ISH) revealed Y-specific targets in 40 out of 69 (60%) of aspirates analysed. A comparison of PCR data obtained from transcervical recovered samples and placental tissues showed a concordance of 80% (76 out of 95), with 10 false positives. Comparing the PCR data from tissues with data derived by ISH from 41 aspirates gave a concordance of 90% with two false positives. Although syncytiotrophoblasts were much more likely to be present in samples containing immunoreactive placental cells, the detection rates of fetal-derived DNA were similar regardless of the morphological and/or immunological presence of placental cells. We conclude that the transcervical recovery of fetal cells, while promising, requires considerable additional effort being expended in further research and development, particular in the sampling procedure.

Non-syncytial sources of fetal DNA in transcervically recovered cell populations.

We have previously shown that fetal DNA can be detected in swabs and flushings obtained from the lower uterine pole prior to the termination of pregnancy. The presence of syncytiotrophoblast vesicles in transcervically retrieved samples suggested that this distinctive placental tissue was an abundant source of fetal DNA and a valuable resource in prenatal diagnosis strategies. In a more extensive study involving 150 terminations of pregnancy between 7 and 17 weeks gestational age, 29% of transcervically retrieved samples contained visible syncytial vesicles. Flushing of the uterine pole more frequently contained syncytia than direct aspiration (39% compared with 26% of samples) but this difference was not statistically significant. No samples > 14 weeks gestational age contained syncytia. Polymerase chain reaction analysis using Y-sequence specific-nested primers indicated the presence of fetal DNA in the absence of intact syncytial vesicles. We therefore examined samples by in-situ hybridization using Y-specific DNA probes. Positive labelling was observed in syncytial vesicles where present and in clumps of unidentified fetal cells. In addition, high numbers of naked nuclei were labelled in samples devoid of syncytia. These isolated nuclei are possibly derived from disrupted syncytia, and may be an important and hitherto overlooked contributory factor in fetal material which collects at the lower uterine pole.

Detection of fetal DNA in trans-cervical swabs from first trimester pregnancies by gene amplification: a new route to prenatal diagnosis?

OBJECTIVE: To determine whether fetal sex can be predicted from fetal DNA retrieved transcervically from the lower part of the uterine cavity in the first trimester of pregnancy. DESIGN: Prospective observational study. SETTING: St James's University Hospital, Leeds. SUBJECTS: 33 women undergoing legal termination of pregnancy at 9 to 13 weeks gestational age. INTERVENTIONS: Before termination of pregnancy samples for DNA analysis were obtained with cotton wool swabs from the vagina, cervix and transcervically in 26 women. In the other seven women samples were obtained using a transcervical cell retrieval (TraCeR) procedure involving flushing the lower uterine cavity with 5 ml saline. MAIN OUTCOME MEASURES: Detection of Y-chromosome specific DNA sequences by the polymerase chain reaction (PCR) in cotton wool swabs taken from the lower uterus in the first trimester of pregnancy to predict fetal sex in comparison with standard cytogenetic analysis. Histological and immunohistochemical analysis of samples obtained by flushing of the lower uterine cavity (TraCeR) to confirm the presence of trophoblast. RESULTS: Fetal sex was predicted accurately in 25 of the 26 pregnancies investigated. Immunohistochemical analysis identified syncytial trophoblast fragments in all seven pregnancies investigated by TraCeR. CONCLUSION: Trophoblast may be retrieved from the lower uterus in the first trimester by swabs or TraCeR. When purification of these syncytial fragments can be achieved using immuno-magnetic technology, this test will enable prenatal diagnosis of single gene defects in the fetus by the polymerase chain reaction.

Adverse urinary symptoms after total abdominal hysterectomy--fact or fiction?

Urinary symptoms before and after total abdominal hysterectomy in a study group of 80 pre-menopausal women were compared with those in a control group of 78 pre-menopausal women who had dilatation and curettage alone. No urinary symptom was found more commonly after hysterectomy than after curettage, whilst stress incontinence was less common in the study group. Transient symptoms occurred more frequently after hysterectomy.

The Stamey endoscopic bladder neck suspension in the elderly.

The Stamey procedure was performed on 21 women aged 65 to 81 years; 17 were cured (completely dry) or significantly improved (maximum 1 pad/day). Urethral length was significantly increased by the operation but maximum urethral pressure and maximum flow rate were unchanged. Complications were few.