Increasing Live Birth Rate by Preimplantation Genetic Screening of Pooled Polar Bodies Using Array Comparative Genomic Hybridization

Abstract

Meiotic errors during oocyte maturation are considered the major contributors to embryonic aneuploidy and failures in human IVF treatment. Various technologies have been developed to screen polar bodies, blastomeres and trophectoderm cells for chromosomal aberrations. Array-CGH analysis using bacterial artificial chromosome (BAC) arrays is widely applied for preimplantation genetic diagnosis (PGD) using single cells. Recently, an increase in the pregnancy rate has been demonstrated using array-CGH to evaluate trophectoderm cells. However, in some countries, the analysis of embryonic cells is restricted by law. Therefore, we used BAC array-CGH to assess the impact of polar body analysis on the live birth rate. A disadvantage of polar body aneuploidy screening is the necessity of the analysis of both the first and second polar bodies, resulting in increases in costs for the patient and complex data interpretation. Aneuploidy screening results may sometimes be ambiguous if the first and second polar bodies show reciprocal chromosomal aberrations. To overcome this disadvantage, we tested a strategy involving the pooling of DNA from both polar bodies before DNA amplification. We retrospectively studied 351 patients, of whom 111 underwent polar body array-CGH before embryo transfer. In the group receiving pooled polar body array-CGH (aCGH) analysis, 110 embryos were transferred, and 29 babies were born, corresponding to live birth rates of 26.4% per embryo and 35.7% per patient. In contrast, in the control group, the IVF treatment was performed without preimplantation genetic screening (PGS). For this group, 403 embryos were transferred, and 60 babies were born, resulting in live birth rates of 14.9% per embryo and 22.7% per patient. In conclusion, our data show that in the aCGH group, the use of aneuploidy screening resulted in a significantly higher live birth rate compared with the control group, supporting the benefit of PGS for IVF couples in addition to the suitability and effectiveness of our polar body pooling strategy.

Non-invasive preimplantation genetic screening using array comparative genomic hybridization on spent culture media: a proof-of-concept pilot study

“…Pooled polar body biopsy and aCGH has previously been described in detail (Feichtinger et al, 2015). Hyaluronidase was used to dissociate the cumulus cells and mechanically remove them before ICSI to prevent maternal cell contamination.…”

“…After washing and drying according to the Illumina 24sure V3 protocol, the slides were scanned using a DNA Microarray Scanner (Agilent Technologies, Santa Clara, USA) at 10 µm resolution. Signals were called with Illumina software (BlueFuse Multi analysis software version 3.0), with adjustment for first polar body analysis as published previously (Feichtinger et al, 2015). Embryos were cultured in single 25-µl droplets using a single step medium (G-TL, Vitrolife, Gothenburg, Sweden) from fertilization until day 5/6 at 37°C with 20% O2 and 6% CO2 in a Galaxy Mini-A incubator (Eppendorf, Hamburg, Germany).…”

“…Non-invasive methods, such as time-lapse, or metabolomics or proteomics analysis of the culture medium, on the other hand, lack accuracy owing to their indirectness (Gardner et al, 2015). Polar body analysis as a minimally invasive technique was suggested to improve live birth rates in patients of advanced maternal age; however, as polar bodies only mirror the oocyte, no paternally derived or mitotic defects can be analysed (Capalbo et al, 2013;Feichtinger et al, 2015).…”

Prevention of in vitro fertilization twins should focus on maximizing single embryo transfer versus twins are an acceptable complication of in vitro fertilization

“…Since this technique needs a sizeable investment, more data must be available before its routine use. Genetic screening of polar body (73) or embryos (74) according to some authorities allows detection of euploid embryos with an increased potential for development. However, that contention is controversial and its use will also remain restricted due to expense.…”

An Economic Analysis of Aneuploidy Screening of Oocytes in Assisted Reproduction in Germany

“…Chromosomal aberrations can develop at different stages of parental meiosis, fertilization and early embryonic development, respectively, with female meiosis considered to be the most common cause of numerical chromosomal anomalies [4 -8]. It was therefore postulated that aneuploidy screening in the context of preimplantation diagnostic genetic testing during ART could increase the live birth rate (LBR) through negative selection of genetically abnormal, non-viable oocytes, and thereby reduce the time to pregnancy [9,10]. One method used for aneuploidy screening is based on the biopsy of polar bodies (PBB) which are extruded by the oocyte during fertilization.…”