Analysis of Parental Abnormal Chromosomal Karyotype and Subsequent Live Births in Chinese Couples with Recurrent Miscarriage

Objective: To identify the influence of parental abnormal chromosomal karyotype on the pregnancy outcomes of recurrent miscarriage (RM) couples. Design: Retrospective cohort study. Setting and Population: 3235 RM couples who experienced two or more miscarriages before 20 weeks were diagnosed in our tertiary referral unit of a university hospital during 2008 to 2018. Main Outcome Measure(s): The frequency and distribution of 121 carriers were described. Pregnant RM carriers (n=55) and non-carriers (n=229) were compared in the etiological factors and pregnancy outcomes. Result(s): Chromosome aberration was detected in 121 (3.74%) among 3235 RM couples which included 75 female and 46 male cases at an individual level. 101 cases were structural aberrations including balanced translocations in 46(38.0%) cases, Robertsonian translocations in 13(10.7%) cases, inversions in 42(34.7%) cases and 20(16.5%) cases were numerical aberrations. 121 carriers during 2008 to 2018 and 428 non-carriers in the 2018 were followed up for two years. 55 carriers and 229 non-carriers were subsequent pregnant after diagnosis by natural conception or intrauterine insemination. The frequency of carriers to have a health newborn was not significantly different with non-carriers (72.7% vs. 71.2%, adjusted p=0.968). Conclusion(s): This study described the majority of carriers were balanced translocations and chromosome aberrations had a limited influence on live birth rate from the present data. The results of the study also remind us that natural conception may be also a good alternative rather than PGD (Pre-implantation Genetic Diagnosis) which is common in many other reproductive centers for such patients.