Table I.
Key findings, from 1971 to 2016, using transcervical retrieval of trophoblast cells.
| Advancements (chronological) | Retrieval method | Trophoblast detection method | References |
|---|---|---|---|
| Trophoblast cells found in cervix | Cervical swab smeared on slide | Y-body stain with quinacrine mustard | Shettles (1971) |
| Confirmation of cervical trophoblast cells | Cervical swabs smeared on slide | PCR for Y-derived sequences | Griffith-Jones et al. (1992) |
| Identification of syncytial trophoblast fragments and protein markers | Uterine lavage | Histology and immunocytochemistry | Griffith-Jones et al. (1992); Chaouat et al. (1994) |
| Detection of fetal trisomy | Uterine lavage | FISH for chromosomes 18 and Y | Adinolfi et al. (1993) |
| Fetal RHD detected in Rh negative women | Cervical mucus aspiration and uterine lavage | PCR | Adinolfi et al. (1995a) |
| Paternal STR allele detection | Endocervical lavage and mucus aspiration | PCR-seq to detect STRs | Adinolfi et al. (1995b); Kingdom et al. (1995) |
| Trisomy 21 detected by STR analysis | Uterine lavage, mucus aspiration and cytobrush | PCR-seq for STRs | Adinolfi et al. (1995c) |
| Detection of fetal SMA and myotonic dystrophy | Endocervical lavage | PCR-seq for STRs | Massari et al. (1996) |
| Trophoblast enrichment by morphology | Endocervical collection and micromanipulation based on morphology | FISH and PCR for Y chromosome | Sherlock et al. (1997) |
| Detection of fetal hemoglobinopathies | Cervical mucus aspiration and micromanipulation based on morphology | PCR-seq for STRs and hemoglobin mutations | Adinolfi et al. (1997); Cirigliano et al. (1999) |
| Identification of female trophoblast cells | Cervical mucus aspiration | PCR-seq for X22 | Adinolfi and Cirigliano (2000) |
| Reliable (97%) cervical trophoblasts recovery | Endocervical collection by cytobrush | FISH | Fejgin et al. (2001) |
| LCM isolation of trophoblasts | Uterine lavage, labeled with anti-HLA-G for LCM | PCR-seq for X, Y and paternal STRs | Bulmer et al. (2003) |
| Trophoblast enrichment with marker antigens | Immunofluorescence labeling and isolation by micromanipulation | PCR-seq for STRs | Katz-Jaffe et al. (2005); Mantzaris et al. (2005) |
| Enrichment of trophoblast based on morphology (152/181) | Uterine lavage and micromanipulation | PCR-seq for STRs | Bussani et al. (2007) |
| Reduced numbers of cervical trophoblast in pathological pregnancies | Endocervical collection by cytobrush | Immunocytochemistry for HLA-G | Imudia et al. (2009) |
| Isolation of >900 EVT cells to >95% purity from Pap specimens by TRIC | Endocervical collection by cytobrush | Immunomagnetic isolation of trophoblast (EVT) with anti-HLA-G | Bolnick et al. (2014) |
| EVT isolation by TRIC is unaltered by gestational age at 5–20 weeks or BMI | Endocervical collection by cytobrush and TRIC | Immunocytochemistry for HLA-G | Fritz et al. (2015b) |
| Trophoblast isolation by size and LCM | External cervical collection by cytobrush and ISET/LCM | Single cell STR genotyping | Pfeifer et al. (2016) |
| EVT protein profiles reflect pregnancy outcomes | Endocervical collection by cytobrush and TRIC | Immunocytochemistry for biomarkers of placental insufficiency | Fritz et al. (2015a); Bolnick et al. (2016b) |
| DNA profiling of EVT by NGS | Endocervical collection by cytobrush and TRIC | Fetal DNA isolation and targeted NGS for SNPs and STRs | Jain et al. (2016) |
STR, short tandem repeats; PCR-seq, Sanger sequencing of fluorescence-labeled PCR products; SMA, spinal muscular atrophy; LCM, laser capture microdissection; EVT, extravillous trophoblast; TRIC, trophoblast retrieval and isolation from the cervix; ISET, isolation by size of epithelial tumor; NGS, next-generation sequencing; SNP, single nucleotide polymorphism; RHD, rhesus blood group D antigen.