User:Z3417753: Difference between revisions
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<pubmed>23477909</pubmed> | |||
This study examines the accuracy of using array comparative genomic hybridisation (array CGH) techniques for the analysis of first and second polar bodies in predicting aneuploidies of maternal meiotic origin in the cleavage stage embryos of women of advanced maternal age. It is known that aneuploidy is a common cause of pregnancy failure, miscarriage and abnormal pregnancy and most aneuploidy is due to maternal meiotic origin and increases exponentially as the mother approaches menopause. | |||
METHOD 20 couples requesting preimplantation genetic screening for advanced maternal age (=greater than or equal to 35 years old) and repeated implantation failure (more than 3 cycles), previous aneuploidy pregnancy or recurrent first trimester miscarriage underwent 16 controlled ovarian hyperstimulation cycles and 7 natural fresh cycles. Male partners had sperm parameters within the normal range except for 2 which had oligoasthenoteratozoospermia. Oocytes were retrieved by ultrasound-guided transvaginal aspiration 36 hours after beta-hCG administration. Once the oocytes were retrieved, biopsy of the first polar body was performed and the oocyte was inseminated using intracytoplasmic sperm injection. The following morning, each oocyte was checked for prouclei and extrusion of the second polar body to confirm fertilisation. The second polar body was then biopsied. The polar bodies were then analysed using array CGH analysis and the zona pellucida layer of the oocyte was dissolved. The zona-free embryo then underwent whole genome amplification and array CGH analysis in the cleavage stage. | |||
RESULTS It has been demonstrated in previous studies that a high correlation exists between the chromosomal status presented from polar body analysis and the actual chromosomes present in the zygotes of older mothers. Due to these results, this study uses polar body analysis and array CGH analysis of mature fertilised oocytes, to identify errors in meiosis within the polar bodies as well as the corresponding cleavage stage embryos. The results of the current study showed that nearly ALL aneuploidies detected in cleavage stage embryos were associated with copy number changes in the polar bodies (93%), indicating the high capability of polar bodies being used to predict aneuploidy and what is actually happening within the embryo. | |||
Revision as of 15:48, 12 August 2014
Welcome to the 2014 Embryology Course!
- Links: Timetable | How to work online | One page Wiki Reference Card | Moodle
- Each week the individual assessment questions will be displayed in the practical class pages and also added here.
- Copy the assessment items to your own page and provide your answer.
- Note - Some guest assessments may require completion of a worksheet that will be handed in in class with your student name and ID.
Individual Lab Assessment |
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Lab 12 - Stem Cell Presentation Assessment | More Info | |
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Group | Comment | Mark (10) |
1/8 |
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7 |
2 |
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7.5 |
3 |
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7.5 |
4 |
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8.5 |
5 |
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8.5 |
6 |
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8.5 |
7 |
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7.5 |
Lab Attendance
--Z3417753 (talk) 12:54, 6 August 2014 (EST)
<pubmed>25084016</pubmed>
Online Assessment 1
<pubmed>23148203</pubmed>
<pubmed>23477909</pubmed>
This study examines the accuracy of using array comparative genomic hybridisation (array CGH) techniques for the analysis of first and second polar bodies in predicting aneuploidies of maternal meiotic origin in the cleavage stage embryos of women of advanced maternal age. It is known that aneuploidy is a common cause of pregnancy failure, miscarriage and abnormal pregnancy and most aneuploidy is due to maternal meiotic origin and increases exponentially as the mother approaches menopause.
METHOD 20 couples requesting preimplantation genetic screening for advanced maternal age (=greater than or equal to 35 years old) and repeated implantation failure (more than 3 cycles), previous aneuploidy pregnancy or recurrent first trimester miscarriage underwent 16 controlled ovarian hyperstimulation cycles and 7 natural fresh cycles. Male partners had sperm parameters within the normal range except for 2 which had oligoasthenoteratozoospermia. Oocytes were retrieved by ultrasound-guided transvaginal aspiration 36 hours after beta-hCG administration. Once the oocytes were retrieved, biopsy of the first polar body was performed and the oocyte was inseminated using intracytoplasmic sperm injection. The following morning, each oocyte was checked for prouclei and extrusion of the second polar body to confirm fertilisation. The second polar body was then biopsied. The polar bodies were then analysed using array CGH analysis and the zona pellucida layer of the oocyte was dissolved. The zona-free embryo then underwent whole genome amplification and array CGH analysis in the cleavage stage.
RESULTS It has been demonstrated in previous studies that a high correlation exists between the chromosomal status presented from polar body analysis and the actual chromosomes present in the zygotes of older mothers. Due to these results, this study uses polar body analysis and array CGH analysis of mature fertilised oocytes, to identify errors in meiosis within the polar bodies as well as the corresponding cleavage stage embryos. The results of the current study showed that nearly ALL aneuploidies detected in cleavage stage embryos were associated with copy number changes in the polar bodies (93%), indicating the high capability of polar bodies being used to predict aneuploidy and what is actually happening within the embryo.