Association of heteromorphism of chromosome 9 and recurrent abortion (ultrasound diagnosed blighted ovum)

Background and Aim : Blighted ovum, also known as anembryonic pregnancy, may lead to cause of early miscarriage at very early in the first trimester of pregnancy. The main characterization of an anembryonic gestation is a normal-appearing gestational sac, but the absence of an embryo .Three main reasons in relation to blighted ovum might be suspected; chromosomal abnormality, abnormal cell division, as well as poor quality of the sperm or the egg which might be resulted in chromosomal abnormalities leading to the cause of blighted ovum . It has been reported that; One third of the products of conception from spontaneous abortion occurring at or before 8 weeks of gestation are blighted ovum . Overall, chromosomal aberrations are the cause of 50% of first trimester spontaneous abortions . The most frequent structural chromosome abnormalities in recurrent miscarriage are translocations (reciprocal translocation, robertsonian translocation . inversions and deletions and duplications . Among the human chromosomes, chromosome no. 9 occurs as a common structural variant which are commonly found in cytogenetic reports and can be observed in 6-8% in the general population . There are some evidences which claim that, there might be potential adverse effects of heteromorphic morphology of chromosome no. 9 and reproductive ability. Until now, the role of any clinical significance of such structural heteromorphism or polymorphism or what is known as heteromorphism which is not thought to has any functional importance is not well understood, but there are some evidences which claim that, there might be a potential adverse effects of heteromorphic morphology of chromosome no.9 and reproductive ability . Methods : Case report In this study we report a history of habitual miscarriages of a couple with unknown etiology. The 30-year-old man and 27-year-old woman who had consanguineous marriage with no history of normal gestation and have had four recurrent spontaneous abortions which diagnosed blighted ovum at 8-10 weeks of gestation. They were initially referred to the infertility center for searching the cause of such pregnancy complication. Hormonal, immunological and anatomical factors of uterus were normal and the partner particularly mother had no underlying disease related to such complication. After obtaining informed consent, chromosomal investigation was performed on the basis of G-banding technique Results : Results : The results showed similar heteromorphism of chromosome no.9 at the same location in both partner [46, XX inv (9p11-q13) and 46, XY inv (9p11-q13)] with normal phenotypes. Conclusion : Conclusion In conclusion further investigation will be suggested in couples with the history of blighted ovum pregnancy and chromosome no.9 heteromorphic in order to postulate a correlation between heteromomorphism (chromosome no. 9) and an embryonic pregnancy.

کلیدواژه ها:

Recurrent abortion ، Heteromorphism ، Chromosome no. 9 ، Pregnancy complication ، Blighted ovum