Maternal age-specific rates of fetal chromosomal abnormalities at 16-20 weeks' gestation in Korean pregnant women >or=35 years of age.
OBJECTIVE
To provide estimates of maternal age-specific rates of fetal chromosomal abnormalities at 16-20 weeks' gestation for Korean women >or=35 years of age.


METHODS
Using the logistic regression method, we analyzed the amniocentesis data of 2,032 gravidas who had fetal karyotyping for the sole indication of advanced maternal age. Also, we compared the prevalence of trisomy 21 among countries using previously published datasets.


RESULTS
The incidence of aneuploidies increased exponentially with maternal age (p < 0.001). The expected rate of trisomy 21 was 3.7 per 1,000 gravidas at 35 years of age. Comparison with other countries showed that Japan has a significantly lower rate of trisomy 21 than North America (p = 0.041; 95% CI 0.522-0.986) and the UK (p = 0.011; 95% CI 0.474-0.909).


CONCLUSIONS
These age-related risk figures are the first data for Korean women. Advanced maternal age was in this study ascertained to be a strong risk factor for chromosomal abnormalities; however, the age-specific risk can be influenced by racial factors.
Park
In Yang
IY
Departments of Obstetrics and Gynecology, College of Medicine, The Catholic University of Korea, Seoul, Korea.
Kwon
Ji Young
JY
Kim
Yun Hee
YH
Kim
Myungshin
M
Shin
Jong Chul
JC
D000328:Adult; D000367:Age Factors; D000649:Amniocentesis; D002869:Chromosome Aberrations; D025063:Chromosome Disorders / Q000453:epidemiology*; D005260:Female; D005865:Gestational Age; D006801:Humans; D008423:Maternal Age; D008875:Middle Aged; D011247:Pregnancy; D012307:Risk Factors