| Research background:The high incidence of birth defects is a huge social problem in China.Prenatal screening and prenatal diagnosis are an effective means of preventing and controlling birth defects,and an important measure of secondary prevention of birth defects in China.To a large extent,they can improve the quality of the birth population and achieve the purpose of eugenics.In recent years,the techniques of prenatal screening and prenatal diagnosis have been developing and progressing,so it is of great theoretical and practical significance to systematically analyze the results of prenatal screening and prenatal diagnosis.Objective:By collecting prenatal screening and prenatal diagnosis of clinical data in the second trimester in a maternity and children s health care centers of Zibo city from 2011 to 2015,to retrospectively analyze the results of prenatal screening and prenatal diagnosis for statistical analysis,including serological screening for down syndrome,noninvasive DNA detection,an amnio prenatal diagnosis and the results of the four-dimensional ultrasound in the second trimester and the follow-up situation.According to the research results,the corresponding countermeasures and Suggestions were put forward to provide a practical basis for the follow-up prenatal screening and prenatal diagnosis work of a maternal and child health hospital in zibo city.Methods:Delfia 1235 automatic time-resolved immunofluorescence analyzer(1235Automatic Immunoassay System)was used to determine the serum markers AFP,Free-P HCG anduE3 of pregnant women aged 18-45 years who were voluntarily selected for prenatal screening and 15-20+6 weeks of gestational weeks.Biochemical values of AFP,Free-? HCG anduE3,combined with age,gestational age,body weight and other factors,risk assessment of fetuses with 21-trisomy syndrome,18-trisomy syndrome,and neural tube defects by Life-cycle software were expected(expected detection rate 60-70%,60-70%,85-90%),respectively,for the screening of low-risk pregnant women do not deal with(only on behalf of the probability of these congenital anomalies is very low,does not completely rule out the abnormality or other abnormalities),for high risk or critical risk pregnant women recall,and recommended amniocentesis or non-invasive DNA testing and imaging testing,and follow-up to 42 days after birth;Ultrasound was used to examine intracranial structure,heart structure,gastric vesicle,kidney,bladder,intestine,limbs of the fetus at 20-28 weeks,to provide ultrasound data for Down's screening,estimate the risk rate,and assess the intrauterine safety.For the diagnosis of deformed children,and can not become normal through intervention after birth,termination of pregnancy will be done,and to trace the pregnancy outcomes of prenatal diagnosis without abnormalities.Results:(1)9243 high-risk pregnant women were in the group,the total positive rate was 5.81%.The high risk rates in five years were 6.63%,6.16%,6.68%,4.67%and 5.79%respectively.Statistical analysis showed there was no significant difference in the high risk rate between years(chi-square test results,P>0.05).(2)The high risk rate of different gestational weeks is also different.The high risk rate of 15-16+6W is 6.92%,the high risk rate of 17-18+6W is 5.39%,and the high risk rate of 19-20+6W is 5.11%.The high risk rate of 15-16+6W is higher than 17-18+6W and 19-20+6W,the difference is significant(chi-square test result,P<0.05),with the comparison of 17-18+6W and 19-20+6W high risk rate,the difference was not significant(chi-square test results,P>0.05).(3)The high risk rate of prenatal screening at different ages is different.The high risk rates of three different age groups are 3.99%,4.96%,and 8.31%respectively.Compared with the 26-30 age group,there was no significant difference in the high risk rate between the ages of 20-25(P>0.05).The high risk rate in the 31-35 age group was significantly higher than that in the first two age groups,and the difference was significant(P<0.05).The regular monitoring,evaluation and adjustment of the median MoM value of each indicator can help to reflect the quality control problems in the screening process and improve the screening efficiency.(4)During the five years from 2011 to 2015,5,638 cases of pregnant women with positive sieving underwent noninvasive DNA testing,and the noninvasive DNA testing rate was 61.00%.The rate of noninvasive DNA detection in 2012,2013 and 2014 was higher than that in 2011,and the difference was statistically significant(P<0.05).The rate of noninvasive DNA detection in 2015 was lower than that in 2011,and the difference was not statistically significant(P>0.05)..The results of noninvasive DNA testing showed that the number of non-invasive DNA positive cases was 304,with a positive rate of 5.39%within five years.Compared with 2011,the positive rate of noninvasive DNA testing decreased in 2012,2013,2014 and 2015,and the difference was statistically sig'nificant(P<0.05).(5)From 2011 to 2015,2166 cases of pregnant women with high risk of prenatal screening were performed with amniocentesis,and the amniocentesis rate was 23.43%.The results of prenatal diagnosis of amniocentesis showed that compared with 2011,2012 and 2013,the rate of amniocentesis increased significantly in 2014 and 2015,with statistically significant differences(P<0.05).Compared with 2014,the rate of amniocentesis decreased significantly in 2015,with statistically significant differences(P<0.05).The diagnosis of amniotic fluid showed that in 2013,2014 and 2015,the diagnosis rate was significantly increased compared with the results of 2011 and 2012,there was a statistically significant difference(P<0.05).A total of 135 cases of fetal chromosomal abnormalities were confirmed by amniocentesis within five years,with a diagnosis rate of 6.23%.(6)In the second trimester,110825 cases of ultrasound prenatal screening were performed,including 6636 cases of major organ malformations including neurological malformation,cardiovascular malformation and digestive tract malformation,with a positive rate of 6%,the reported positive rate was 6.6%according to Chen Yu et al.That was no significant difference.After follow-up examination,the number of false positive cases was 670,the false positive rate was 0.6046%,the number of missed cases was 86,and the missed diagnosis rate was 1.30%.Suggestions:To improve the cognitive level of pregnant women and their families;to do a good job in the publicity and education of prenatal screening and prenatal diagnosis;to fully inform pregnant women and their families of the gestational range,examination indications,examination procedures and matters needing attention of various examinations;Improve the service awareness and technical level of medical staff,improve the rate of prenatal screening,do a good job in laboratory control to reduce false positive rate and false negative rate,try to do all pregnant women who visit the doctor with Down' serological screening and four-dimensional ultrasound screening;Strict prenatal screening indications of noninvasive DNA testing,to inform the advantages and disadvantages of noninvasive DNA testing in detail to reduce screening risks;Strict prenatal diagnostic indications of amniocentesis can improve the rate of amniocentesis. |
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