[Risk factors for structural chromosomal abnormality in > or = 2 miscarriages, as an instrument for selective karyotyping].
OBJECTIVE
To identify additional risk factors and the corresponding probability of carrying a chromosome abnormality in couples with two or more miscarriages.


METHODS
Nested case-control study.


METHODS
In 6 centres for clinical genetics in the Netherlands, data were collected from couples referred for karyotyping after 2 2 miscarriages from 1992-2000. Factors influencing the probability of carrier status were examined. The corresponding probability of carrier status was calculated for the various combinations of these factors.


RESULTS
In total 279 carrier couples and 428 non-carrier couples were included. 4 independent factors influencing the probability of carrier status were identified: a younger maternal age at the time of second miscarriage, a history of > or = 3 miscarriages, a history of > 2 miscarriages in a brother or sister of either partner, and a history of> 2 miscarriages in parents of either partner. The calculated probability of carrier status in couples referred for chromosome analysis after two or more miscarriages, varied between 0.5-10.2%. In 18% of couples included, the risk was found to be so low (< 2.2%), that in couples with comparable risk factors, it may not be necessary to perform karyotyping.


CONCLUSIONS
This study demonstrated that the probability of carrier status in couples with > or = 2 miscarriages is modified by additional factors. Selective chromosome analysis would result in a more effective referral policy and therefore decrease the number of chromosome analyses and lower the costs.
Franssen
M T M
MT
Academisch Medisch Centrum/Universiteit van Amsterdam, Postbus 22.660, II00 DD Amsterdam. m.t.m.franssen@og.umcg.nl
Korevaar
J C
JC
Leschot
N J
NJ
Bossuyt
P M M
PM
Knegt
A C
AC
Gerssen-Schoorl
K B J
KB
Wouters
C H
CH
Hansson
K B M
KB
Hochstenbach
P F R
PF
Madan
K
K
van der Veen
F
F
Goddijn
M
M
D000026:Abortion, Habitual / Q000235:genetics*; D000022:Abortion, Spontaneous / Q000235:genetics; D000328:Adult; D016022:Case-Control Studies; D002869:Chromosome Aberrations; D005260:Female; D006580:Genetic Carrier Screening; D020022:Genetic Predisposition to Disease; D005820:Genetic Testing; D006579:Heterozygote; D006801:Humans; D007621:Karyotyping; D008297:Male; D008423:Maternal Age; D018579:Patient Selection; D011247:Pregnancy; D018570:Risk Assessment; D012307:Risk Factors