The Study About Occupational And Environmental Influence Factors For Down's Syndrome

Objective:This study is aimed at describing the distribution of Down's Syndrome in different groups such as age,and examine the pattern ad trend of its occurrence over time and by geographic area,and exploring influence factors of Down's Syndrome by case control study so to providing epidemiological foundations for etiological study of Down's Syndrome and reducing the incidence of down's syndrome,so that we can achieve the goal of primary prevention.Methods:A prevalence survey was conducted among pregnant women who had examined fetus' chromosomal karyotype at Guangdong Maternity and Child Care Hospital during 1January 2015 to 31 December 2015.We collected and analyzed maternal medical history messages and analysis the distribution of Down's Syndrome in different groups such as age,and examine the pattern ad trend of its occurrence over time and by geographic area.A case-control study was conducted among fetuses whose chromosomal karyotype was determined trisomy 21 or not at Guangdong Maternity and Child Care Hospital during 1January 2015 to 31 December 2016.Results:(1)We had collected a total of 2342 pregnant women,which consist of 63 Down's syndrome fetus and 2279 other fetus.Relevance ratio of Down's syndrome among the year of 2015 was 2.69%.Down's syndrome fetus include 1 mosaicism karyotype and 62 trisomy karyotype.(2)The ratio of Down's syndrome is more high in January(3.9%),July(4.3%)and December(4.1%)and it is lower in March(0.9%)and September(1.7%).(3)Women live in city have less chances to breed a fetus with Down's syndrome than who live in countryside(?2=7.88,P<0.01).(4)Logistic regression analysis showed that Down's syndrome occurred with more chances when maternal age was more than 35(?2=16.600,OR=2.755),oral contraceptive use before pregnancy(?2=0.807,OR=6.860),maternal occupational expose to organic substance containing benzene(?2=5.789,OR=2.589),or live in new house before pregnancy(?2=10.664,OR=3.080).On the contrary,the odds ratio for maternal use of folic acid before pregnancy was significantly decreased(?2=0.814,OR=0.107).Conclusions:The occurrence of Down's syndrome may be affected by climate and differences between urban and rural areas.There are multiple influence factors of Down's syndrome including maternal age more than 35,oral contraceptive use before pregnancy,maternal occupational expose to cosmetics,or benzene,live in new house before pregnancy,and also some protective factors such as maternal use of folic acid.In conclusion,it is extremely essential to perfect occupational protection,strengthen eugenic propaganda and preconception counseling.