Chromosomal abnormalities in couples with recurrent abortions in Lagos, Nigeria

Abstract

The study was to investigate the prevalence of chromosomal abnormalities in  couples with two or more recurrent miscarriages of unknown cause. The study  population included 55 women and 32 male partners with medical history of 2 or  more consecutive abortions and primary infertility. The controls were 20 healthy  couples with at least one live delivery and without a history of pregnancy loss.  Individuals with medical disease or reproductive organic abnormality were excluded from the study. Chromosomal analysis was performed on peripheral blood   lymphocytes cultured for 72 hours, using Trypsin-Giemsa (GTG) banding. In all cases, at least 20 metaphases were analyzed and 2 karyotypes were prepared, using light microscopy. Out of 78 cases of karyotype analyzed, 6 cases (7.7%) of abnormal chromosome karyotypes and two (2) Y chromosome variants (2.56%) were seen. No case of structural anomaly was seen. There was no case of  chromosomal abnormality seen among the control group in this study. The median age and age range of couples with recurrent miscarriages were 33 years and 28-42 years respectively for the females and 37 and 31-51 years for the males. The male to female ratio is 1:1. The most frequent age group of involvement is 35-39  (44.9%) followed by 30-34 (33.3%) and then 40-44(14.1%) Chromosomal  alterations affected most commonly age group 30-34(3.84%) followed by group 40-44 (2.56%). All the groups have equal average number of pregnancy wastage of 4 per couple. Of the 6 abnormal cases, 1 case (1.28%) each of the mosaic  Kleinfelter syndrome (XXY) and Superman (XYY) as well as 2 cases of   translocations made up of reciprocal and Robertsonian types. Also seen are 1case (1.28%) each of mosaic Turners syndrome and trisomy X. An association between chromosomal abnormalities and recurrent miscarriage of pregnancy was observed in
the study. Etiologic identification of genetic factors represents important clinical information for genetic counseling and orientation of the couple about the risk for future pregnancies and decreases the number of investigations needed to elucidate the possible causes of miscarriages.

Keywords: Chromosomal abnormalities, recurrent miscarriages, Genetic counselling.