Introduction
Recurrent miscarriage (RM) is defined by the ESHRE guidelines in November
2017 as the loss of two or more pregnancies[1]. According to the
history of live birth, it can be divided into primary and secondary
recurrent miscarriage[2]. The causes of recurrent miscarriage are
very complicated. In addition to anatomy, endocrine, thrombophilic,
immune and other factors,embryo chromosomal abnormalities are often
considered an important cause of miscarriage[3, 4]. The embryo
chromosomal abnormality rate in the general population is 60%[5],
while the rate in the recurrent miscarriage is 29%-60%[6-8].
Embryonic chromosomal abnormalities may occur during the mitosis of
embryo development, or come from parental abnormal ovum or sperm. For
example, parental balanced chromosomes lead to unbalanced gametes which
might cause abortion [9]. Therefore, the chromosomal karyotype of
both parents is considered to be an important examination in the cause
of recurrent miscarriage recommended by American Colleges of
Obstetricians and Gynecologists[10]. However, the evidence that
parental chromosomal abnormalities lead to miscarriage is still unclear,
a considerable percentage of couples with chromosomal abnormalities have
successfully given birth[11]. In addition to chromosomal factors,
other factors may cause miscarriages that coexist with chromosomal
aberrations. Due to the limited number of samples in couples with
abnormal chromosomes, other known and unknown pathological factors were
studied as homogeneous, and chromosome aberrations could hardly
completely solely studied with removal of other pathological factors.
Therefore, it is more difficult to judge and analyze the cause of
miscarriage due to parental chromosomal abnormalities, which often makes
clinicians’ understanding of parental chromosomal abnormalities leading
to miscarriage not accurate enough.
5680 couples with recurrent miscarriage were diagnosed in our
reproductive center from 2008 to 2018. The study attempts to summarize
the frequency of abnormal chromosomal karyotype couples, the topography
of abnormal types, and the frequency of the male and female carriers in
the recurrent miscarriage population. The coexistence of other causes of
miscarriage and respective pregnancy outcomes were further evaluated. We
hope that the results of the study will provide more scientific
evidences for genetic counseling among RM couples.