Recurrent miscarriage Flashcards
% of pregnancies which miscarry?
15-20%
% of miscarriages which are chromosomally abnormal?
50%
Common examples of chromosomal trisomies found in miscarriage?
16, 21 and 22
What test can be used to detect chromosomal trisomies?
Extended QF-PCR
% of a) Patau and b) Downs pregnanies which miscarry?
a) 95% b) 80%
Recurrence risk after a couple has a single pregnancy with an autosomal trisomy?
1%
If a couple experiences the same trisomy in a second pregnancy what could be the explanation for this, and how could this be mitigated?
One of the parents may be gonadal mosaic for the trisomy; prenatal test in future pregnancy
% of couples who experience recurrent miscarriage due to a balanced rearrangement?
5%
Why do balanced rearrangements cause miscarriage?
Malsegregation of the balanced rearrangement leading to unbalanced sperm/eggs –> unbalanced conception
Commonest types of balanced rearrangements? (3)
Balanced translocations (e.g. Robertsonian, autosomal, X-autosomal)
Balanced inversions
Balanced insertions
