DNA ploidy of ectopic pregnancy and first trimester spontaneous abortion investigated by flow cytometry

Novel ploidy analysis in ectopic pregnancy

Objective

To study whether a single-nucleotide polymorphism (SNP) array could be used to test tissue from ectopic pregnancy to distinguish whether ectopic pregnancies were aneuploid.

Design

Case series report.

Setting

Academic medical center.

Patients

One hundred seventy-eight women who underwent surgery for ectopic pregnancy at Northwestern Memorial Hospital between 2015 and 2018 were eligible for participation; written consent was obtained from 33 patients. Eight subjects had sufficient DNA samples and were included in the analysis. Maternal and paternal DNA samples were self-collected by buccal swab. Archived paraffin tissue containing chorionic villi from each surgically removed ectopic specimen was analyzed using SNP microarray technology to determine chromosome number and evaluate for maternal cell contamination.

Interventions

None.

Main Outcome Measures

Prevalence of aneuploidy in ectopic pregnancy specimens as well as success of SNP array technology in formalin-fixed and paraffin-embedded specimens.

Results

Subjects had a mean (±SD) age of 33.4 ± 5.4 years, body mass index of 23.4 ± 5.7 kg/m², 3.3 ± 1.8 prior pregnancies, and 1.5 ± 1.4 live births. Genetic testing revealed that all eight tested samples were euploid, 6 female and 2 male (two arr(1-22)x2, (X,Y)x1 and 6 arr(1-22, X)x2); maternal cell contamination was ruled out in all cases.

Conclusions

This study showed proof of concept for the use of routinely stored formalin-fixed, paraffin-embedded tissue blocks with DNA extraction for SNP array to detect ploidy status of ectopic pregnancy. Although all tested samples were euploid, further research is needed to gain a definitive answer to this question and better understand the mechanism that leads to ectopic implantation.

Comparative genomic hybridization of ectopic pregnancies that fail methotrexate therapy

Ectopic pregnancies that fail methotrexate therapy are predominantly euploid by comparative genomic hybridization (CGH). This feasibility study also confirms that formalin-fixed paraffin-embedded gestational tissue can successfully undergo CGH.

Assisted hatching is associated with a higher ectopic pregnancy rate

In a retrospective analysis of 623 clinical pregnancies conceived after IVF, a 5.4% ectopic pregnancy rate (14/258 clinical pregnancies) was found in cases where assisted hatching (AH) was performed compared to 2.2% (8/365) in the group without assisted hatching. In view of the widespread use of AH, it may be relevant to assess the effect of AH on the incidence of ectopic pregnancy in a large multicenter effort.

Association of histologic features and cytogenetic abnormalities in ectopic pregnancies

OBJECTIVE

To evaluate the association between specific histologic features and cytogenetic abnormalities in ectopic pregnancies.

DESIGN

Blinded histologic analysis.

SETTING

University hospital.

PATIENT(S)

Fifty-four patients with ectopic pregnancy for whom successful karyotypes and sufficient histologic material were available.

INTERVENTION(S)

Histologic evaluation of chorionic villi from ectopic pregnancies was done by two pathologists who were unaware of the cytogenetic outcome. Seventeen histologic features were evaluated: villus size, villus contour, ghost villi, hydropic villi, trophoblastic hyperplasia, trophoblastic hypoplasia, syncytial knots, Hofbauer cells, blood vessels, trophoblastic lacunae, trophoblastic inclusions or cisterns, degeneration, fibrohyalinization, microcalcifications, and perivillous and intervillous fibrin deposits.

MAIN OUTCOME MEASURE(S)

The association between histopathologic features and cytogenetic outcome.

RESULT(S)

The presence of ghost villi and intervillous or perivillous fibrin was found to be associated with cytogenetic abnormalities. These features are associated with previous fetal cell death.

CONCLUSION(S)

This study does not support an association between specific histologic features of chorionic villi and cytogenetic abnormalities in ectopic pregnancies. The only histologic features that were associated with cytogenetic abnormalities (i.e., ghost villi and intervillous and perivillous fibrin) are merely a result of previous fetal cell death.