An unbalanced translocation means there is extra or missing genetic material—typically a combination of partial trisomy and partial monosomy. This can occur in embryos conceived naturally or via IVF, especially if one parent is a balanced translocation carrier.
What it may cause
The impact depends on which chromosomal segments are affected, but risks can include:
- failure to implant,
- miscarriage,
- fetal structural anomalies,
- growth restriction,
- developmental or medical concerns after birth.
How we diagnose it
- Chorionic villus sampling (CVS) or amniocentesis during pregnancy (when indicated)
- Chromosomal microarray (CMA) to detect gains/losses
- Karyotype and/or targeted testing to determine whether a parent carries a balanced rearrangement
IVF planning
If an unbalanced translocation is known or suspected:
- IVF with PGT-SR can help reduce transfer of embryos with the same imbalance pattern.
- A genetics team can explain residual risks and what testing is recommended in pregnancy.
FAQ
- Can unbalanced translocation be mild? Sometimes, yes—severity varies by segment and size.
- If we do PGT-SR, is pregnancy testing still needed? Many clinics still recommend confirmatory prenatal testing depending on circumstances.
CTA: Ask us about CMA, karyotyping, and PGT-SR if you’ve had losses or abnormal results.