[Chromosomal rearrangements as the cause of habitual abortions].
BACKGROUND
Habitual abortion is a spontaneous abortion occurring in three or more successive pregnancies with no intervening pregnancies. Chromosomal aberrations account for approximately 50% of foetal losses prior to 15 weeks.


OBJECTIVE
The aim of this study was to determine the role of chromosomal rearrangements in aetiology of habitual abortions in couples with a normal karyotype.


METHODS
We analysed the karyotype of placental tissue, taken from spontaneously aborted foetuses from couples with normal karyotype and habitual abortions. The women tested were divided into two groups. In the first group, there were 23 women below 35, and in the second, 13 women above 35 years of age. Tissue samples were obtained from the abortions and processed using standard techniques. All specimens were G-banded using trypsin-Giemsa stain. Sixteen metaphase cells were analysed for their chromosome constitution in each sample. For statistical analysis, we used chi2 test.


RESULTS
From 36 analysed cases, there were 17 (47.2%) with an abnormal chromosomal constitution and 19 (58.2%) with a normal chromosomal constitution. Trisomy 16 was detected in 4 cases. Among sex chromosomal aberrations, only monosomy X was found in 3 cases. Two cases of triploidy and two cases of trisomy 8, 18 and 21 were detected. Trisomy 12 and trisomy 13 were found in one case each. In group of women under 35 (I group), the percentage of chromosomally abnormal foetuses was 34.8%, while in the group of women above 35 (II group), that percentage was 69.2, but there was no statistically significant difference between groups I and II (chi2 = 3.01 < chi2 (1 and 005) = 3.841).


CONCLUSIONS
Hereditary base defects are a significant cause of spontaneous abortions in early pregnancy. Detection of chromosomal abnormalities provides the opportunity to plan further treatment of reproduction disorders.
Petrović
Bojana
B
Ljubić
Aleksandar
A
Mićić
Miroslava
M
D000026:Abortion, Habitual / Q000235:genetics*; D002869:Chromosome Aberrations; D005260:Female; D006801:Humans; D011247:Pregnancy