Novel Ploidy Analysis in Ectopic Pregnancy

ABSTRACT Objective To study whether single nucleotide polymorphism 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 178 women who underwent surgery for ectopic pregnancy at Northwestern Memorial Hospital between 2015-2018 were eligible for participation; written consent was obtained in 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 underwent analysis using single nucleotide polymorphism microarray technology to determine chromosome number and evaluate for maternal cell contamination. Intervention 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 age of 33.4±5.4 years, BMI 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 8 tested samples were euploid, six female and two male (two arr(1-22)x2, (X,Y)x1 and six arr(1-22, X)x2) and 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. While 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.