Retrieval of trophoblast cells from the cervical canal for prediction of abnormal pregnancy: a pilot study
Authors: Imudia, Anthony N.; Suzuki, Yoko; Kilburn, Brian A.; Yelian, Frank D.; Diamond, Michael P.; Romero, Roberto; Armant, D. Randall
Source: Human Reproduction, Volume 24, Number 9, 28 September 2009 , pp. 2086-2092(7)
Publisher: Oxford University Press
Fetal cells are shed from the regressing chorionic villi and it is possible to retrieve extravillous cytotrophoblast cells by transcervical sampling. The abundance of trophoblast cells in transcervical samples suggests that this non-invasive approach could distinguish between normal and abnormal pregnancies, such as an ectopic pregnancy (EP) and blighted ovum (BO). We aim to identify and quantify fetal trophoblast cells in the cervical canal during the first trimester to assess their usefulness to predict an abnormal pregnancy.
Patients, age 1845, presenting with a normal intrauterine pregnancy (IUP; n 37), diagnosis of EP (n 10) or BO (n 5) were enrolled for collection of transcervical specimens using a cytobrush and fixative rinse. Non-pregnant, nulliparous women (n 7) were included as negative controls. Cells were cleared of mucus by acidification, prepared on microscope slides and labeled with a monoclonal antibody recognizing the trophoblast marker, human leukocyte antigen (HLA)-G. HLA-G positive and negative cells were counted to calculate the ratio of trophoblast cells to total cervical cells.
Trophoblast cells were observed in 35/37 normal IUP, 6/10 EP and 4/5 BO specimens. The average frequency of HLA-G positive cells in the normal IUP cervical samples was 1 in 2000, which was 4-fold higher than samples from patients with EP or BO (P < 0.001). Receiver operating characteristic analysis showed that EP and BO pregnancies were distinguishable from normal pregnancies with 93 sensitivity, 95 specificity, 97 positive predictive value and 87 negative predictive value.
This pilot study presents evidence that trophoblast cells can be reliably obtained and identified among cervical cells in the first trimester by immunohistochemical staining for HLA-G, and suggests for the first time that abnormal pregnancies may be predictable based on the abundance of trophoblast cells in the cervical canal.
Document Type: Research Article
Publication date: 2009-09-28
- Human Reproduction features full-length, peer-reviewed papers reporting original research, clinical case histories, as well as opinions and debates on topical issues. Papers published cover the scientific and medical aspects of reproductive physiology and pathology, endocrinology, andrology, gonad function, gametogenesis, fertilization, embryo development, implantation, pregnancy, genetics, genetic diagnosis, oncology, infectious disease, surgery, contraception, infertility treatment, psychology, ethics and social issues. The highest scientific and editorial standard is maintained throughout the journal along with a rapid rate of publication.