Purpose: To report the normal live birth and birth defect rates pre- and post- preimplantation genetic testing for chromosomal structural rearrangements (PGT-SR) in reciprocal translocation carriers who have experienced two or more unfavorable pregnancy histories.
Methods: We conducted a retrospective cohort study of 194 couples who underwent 265 PGT-SR cycles between January 2013 and August 2016. The rates of miscarriage, normal live birth, and birth defect pre- and post- PGT-SR treatment were recorded. The types of birth defect were also categorized.
Results: Before PGT-SR treatment, the 194 couples with reciprocal translocation had a previous reproductive history consisting of 592 pregnancies in total: 496 (83.8%) were miscarriages; 29 (4.9%) ended by induced abortion due to unintended pregnancy; 36 (6.1%) had birth defects; and 17 (2.9%) were normal live births. After PGT-SR treatment, there were 118 clinical pregnancies. Of these pregnancies, 13 (11.0%) were miscarriages, 101 (85.6%) were normal live births, and 4 (3.4%) had birth defects. In total, 14 different disorders were noted in the prenatal and postnatal examinations. Before the PGT-SR treatment, multiple birth defects, central nervous system abnormalities, and congenital heart defects were the three most common congenital malformations. Excluding for methylmalonic acidemia, there were only single and mild birth defects after the PGT-SR treatment.
Conclusions: After the PGT-SR treatment, the reciprocal translocation carriers who had previously experienced two or more unfavorable pregnancy outcomes had a low risk of miscarriages and birth defects. The rate of normal live births per pregnancy was higher after PGT-SR treatment.
Keywords: Balanced translocation; Birth defect; Live birth; Miscarriage; Preimplantation genetic testing.