Balanced Structural Chromosomal Anomalies in Couples with Recurrent Pregnancy Loss (RPL)

Background: Balanced structural chromosomal anomalies revealed in 2-5% of couples with RPL. Unbalanced form of such anomalies, transmitted to embryos, can cause pregnancy loss.

Objective: Detection of frequency and types of chromosomal anomalies in couples with RPL.

Methods: 112 couples (aged 20-44yy.) with > 2 miscarriages (I trimester) were investigated in 2011-15. Besides of collecting comprehensive family and personal anamnesis, anatomic, hormonal, immunological, thrombophilic and genetic causes of RPL have been studied. Detection of karyotype was performed in peripheral blood lymphocyte culture (G-banding).

Results: Pregnancy and delivery with abnormal fetus, as well as karyotype of previous abortuses, were not detected in any cases. Chromosomal anomalies in one parent were revealed in 9 cases (8%). Balanced reciprocal translocation was detected in 4 men and 2 women, Robertsonian translocation – in 1 man. 2 from 5 men with translocations were subfertile. Total frequency of balanced translocations was 7 (6,25%). One woman had pericentric inversion of chromosome 9 and one woman – mosaic karyotype 46,XX/47,XXX. Mean number of previous miscarriages in common group of RPL was 3.15 and in the couples with chromosomal anomalies – 2.9.

Conclusion: In the couples with RPL and no history of delivery with abnormal fetus, when chromosomal status of previous miscarriages is unknown, significant frequency of balanced structural chromosomal anomalies indicates on reasonability of karyotyping of such couples, especially when male partner is subfertile. The reproductive risks (including miscarriage) are influenced by the size and the genetic content of the rearranged chromosomal segments and the sex of carriers.