Home collection of products of conception: can karyotypes be obtained?

Abstract

To investigate the ability to perform chromosomal analysis on products of conception following use of misoprostol, expectant management, or dilation and curettage (D&C) after miscarriage. This was a case series of patients who had first-trimester pregnancy losses and desired chromosomal analysis of the products of conception (POC) in 2015-2017 at the Oregon Health & Science University fertility center. This study investigated patient preference in management of losses, whether karyotype was successfully completed on POC, if prolonged time between diagnosis and receipt of tissue still resulted in successful analysis, and frequency of aneuploidy among these patients. This IRB approved study included patients seen between January 2015-December 2017 who had first-trimester miscarriage identified on ultrasound, and desired POC single nucleotide polymorphism (SNP) analysis through an outside lab. Patients chose D&C, misoprostol, or expectant management to manage their miscarriages. Patients who chose misoprostol or expectant management self-collected samples; samples were examined by an RN prior to analysis. The method of obtaining POC tissue, time between diagnosis of pregnancy loss and receipt of tissue by the lab, and karyotype outcomes were included. Chi-squared testing between proportions was performed using Graphpad Prizm 7.04. A total of 24 patients with ultrasound diagnosis of miscarriage desired chromosomal analysis of POC. Of these patients, 6 chose D&C, 16 chose misoprostol, and 2 chose expectant management. Chromosomal analysis was successfully obtained for 6/6, 8/16, and 1/2 of patients choosing D&C, misoprostol, and expectant management, respectively (p=0.0165). Maternal cell contamination (MCC) was present for 8/10 patients between 1/2015-2/2016; only 1/14 of results from 3/2016-12/2017 showed MCC. Timing of diagnosis of miscarriage to POC receipt by lab ranged from 3-16 days, median 9 days. Aneuploidy was found in 8/15 of samples. Traditionally, physicians have advised patients interested in POC analysis that D&C is a superior option to obtain tissue for testing. While our results confirm this finding, this preliminary study shows that home POC collection can result in satisfactory tissue for SNP analysis, with the caveat that a higher incidence of MCC may be found versus D&C samples. With development of SNP analysis, only small amounts of tissue are required. Fewer MCC results in later years may demonstrate improvements in testing or provider experience in isolating chorionic villi. This study suggests that chromosomal analysis is an option for patients disinclined to have D&C, and tissue obtained up to 16 days after diagnosis can yield useful results. Patients should be counseled that D&C provides the most reliable method for accurate chromosomal analysis, but alternate methods to obtain POC can be considered.