ABSTRACT
It must be emphasized in the maternal serum prenatal screening that the quality is not only influenced by accuracy of biomarker assay,risk calculation parameters and biomarker database,but also influenced by clinical factors such as gestational weeks,weight and ect.The result of prenatal screening is just a risk evaluation,the subsequent diagnosis and the follow-up are more important.It is expected to improve screening efficiency by localization of prenatal screening database and making the quality management of the prenatal screening-diagnosis suitable for the national conditions.On the other hand,prenatal screening in the women of advanced maternal age and twin pregnancy,improve amniotic fluid cell culture method,chromosome analysis automation,the introduction and positioning of rapid prenatal molecular diagnosis techniques become the hot issues.
ABSTRACT
Objective To establish D-dimer normal reference range in pregnant and postpartum women in Zhejiang Han population.Methods Plasma samples were collected from 669 healthy pregnant women, 578 healthy postpartum women, 8 venous thrombosis or DIC patients and 80 healthy non-pregnant women in Women′s Hospital, School of Medicine, Zhejiang University from March 2009 to August 2010.According to different gestational week, postpartum days and delivery pattern, the healthy pregnant and postpartum women were stratified into 3 groups: (1) ≤13 weeks (n=120), 14-20 weeks (n=120), 21-27 weeks (n=145), 28-34 weeks (n=147), ≥35 weeks (n=137);(2) The first day after vaginal delivery (n=163), the second day after vaginal delivery (n=121);(3) The first day after cesarean sections (n=166), the second day after cesarean sections (n=128). These groups were further stratified based on age: ＜30 years old and ≥30 years old.All blood samples were drawn in citrate sodium anticoagulated blood.D-dimer concentration was determined by STA-R Evolution coagulation analyzer.Since D-dimer concentration showed non-normal distribution, the normal values (one-tailed) were established by using (P95) percentile method.The results of 8 patients were used to validate the established normal values.Results In the group of ＜30 years old, the D-dimer values[M(P25-P75)]in group of ≤13 weeks, 14-20 weeks, 21-27 weeks, 28-34 weeks, ≥35 weeks and healthy non-pregnant women were 0.25(0.17-0.37), 0.51(0.38-0.75), 0.75(0.57-1.10), 1.14(0.80-1.48), 1.60(1.14-1.89) and 0.20(0.10-0.28) mg/L, respectively, which showed statistical difference(H=239.24, P＜0.05).In the group of ≥30 years old, the D-dimer values of the above different groups were 0.28(0.14-0.38), 0.50(0.36-0.65), 0.83(0.59-1.41), 0.93(0.68-1.37), 1.47(1.22-1.84) and 0.17(0.12-0.25) mg/L, respectively, which also showed statistical difference(H=127.75, P＜0.05).In the group of ＜30 years old, the D-dimer values were 2.45(1.51-3.77), 1.30(0.97-1.96), 2.68(1.52-3.74) and 1.55(1.10-2.10) on the first and second day after vaginal delivery and cesarean section, respectively, which showed statistical difference (H=64.85,P＜0.05).In the group of ≥30 years old, the corresponding values were 2.20(1.33-3.54), 1.33(1.02-2.14), 2.27(1.66-3.17) and 1.62(1.26-2.69), respectively, which also showed statistical difference(H=18.64, P＜0.05).D-dimer normal values were established based on different gestational week, postpartum days and delivery pattern.The normal values of ≤13 weeks, 14-20 weeks, 21-27 weeks, 28-34 weeks and ≥35 weeks were ≤0.64 mg/L, ≤1.54 mg/L, ≤2.60 mg/L, ≤3.01 mg/L and ≤3.19 mg/L, respectively. The normal values of 1st day after vaginal delivery, 2nd day after vaginal delivery,1st day after cesarean sections and 2nd day after cesarean sections were ≤7.83 mg/L, ≤3.29 mg/L, ≤9.95 mg/L and ≤3.80 mg/L.All 8 patients showed positive results with the above normal values.Conclusion D-dimer normal values in pregnant and postpartum women in Zhejiang Han population are established, which can improve the application values of D-dimer in the pregnant and postpartum population.
ABSTRACT
Prenatal diagnosis is used for discovery of pregnant mothers' fetus abnormalities, ranging from maternal serum screening, cytogenetic analysis for chromosome karyotypes, to molecular genetic diagnosis. It is therefore the primary approach to prevent and reduce birth defects. Based on the experience obtained from developed countries, large-scale prenatal diagnosis has been carried out in China, including maternal serum screening for Down syndrome, prenatal diagnosis of chromosomal diseases, and certain gene analysis for genetic diseases. However, it is noted that such development is uneven in different regions. As a great disease-prevention project involving steady development of the nation and the ethnic groups, it is still necessary to establish or improve the prenatal diagnosis system and quality management regulations that are fit for the domestic conditions of China.
ABSTRACT
[Objective] To construct a database for the genetic polymorphism of 18 STR loci (D8S1179, D21S11, D7S820, CSFIPO, D3S1358, TH01, D13S317, D16S539, D2S1338, D19S433, VWA, TPOX, D18S51, D5S818, FGA, PentaE, PentaD, SE33) in Hart population from Zhejiang province. To investigate the application of 18 STR loci in the field of paternity testing and prenatal diagnosis. [Methods] Fluorescent dye labeling multiplex STR-PCR, capillary electrophoresis and DNA sequencer GeneScan were adopted in genotyping 598 unrelated samples collected from Han population in Zhejiang province. 18-STR database was established and analyzed. Population comparison was conducted between Han population in Zhejiang province and 8 other population. 15-STR and 18-STR identification system were compared in 497 paternity testing cases. [Results] We observed the distribution of 18 STR loci in Han population meet Hardy-Weinberge equilibrium and was different from other 8 population (X~2 test, P>0.05). Statistical results showed that the heterozygosis (He) ranged from 0.630 to 0.942. The combined power of discrimination was>0.9999999999. Compared with 15-STR identification system, higher paternity index scores and higher exclusion rate were obtained with 18-STR identification system in dual-case paternity test and mutation identification. One trisomy 21 fetus was found in a prenatal paternity test case which had two characteristic genotypes in 2 STR loci of D21S11 and Penta D. [Conclusions] The 18 loci were relatively highly genetic polymorphic in Zhejiang Han population and could be used for paternity testing. Some STR loci could be used in prenatal diagnosis for aneuploidy.
ABSTRACT
Objeetive To evaluate the performance characteristics of the second trimester double test for the detection of fetal Down's syndrome(DS)in women of advanced maternal age(AMA).Methods We undertook a prospective nation-wide multi-centered study and chose alpha-fetoprotein(AFP))and free β-subunit of human chorionic gonadotrophin(free β-hCG)as the serum markers.Between May 2004 and September 2006,12 centers participated in the collection and analysis of maternal serum AFP and free β-hCG.Patients with an iuereaged risk of DS(≥1/270)wero offered generic sunniocentesis.Follow up of the outcome of all pregnancies was obtained.Patients were divided into two groups,the AMA group and the non-AMA group and the screening efficiency Was evaluated in beth groups.Results A total of 66 132 singleton pregnancies were included in the study.and there were 36 10(5.46%)AMA women.The median maternal age of AMA women was 36.8years(35-47 years).At a cut-off of 1/270,in the AMA group,the number of positive cases screened was 727 and 22 cases of fetal DS were detected:the number of negative cases screened was 2883,and no fetal DS was found.In the non-AMA group,the number of positive cases screened was 4743 and 69 cases of fetal DS were detected:the number of negative cases screened was 57 779,and 6 cases of fetal DS were diagnosed postnatally.In AMA group,the detection rate(DR),false positive rate(FPR)and odds of being affected given a positive result(OAPR)were 100%,19.7%and 3.0%respectively.In the non-AMA group,the DR,FPR and OAPR were 92.0%.7.5%and 1.5%respectively.Conclusion The double-marker test using AFP and free β-hCG is an effective screen strategy for second-trimester detection of Down syndrome in AMA women.
ABSTRACT
Objective To evaluate the performance characteristics of the second trimester double-marker test for the detection of fetal Down's syndrome in mainland China. Methods This prospective national multi-centered study used alpha-fetoprotein (AFP) and free β-subunit of human chorionic gonadotrophin( free β-hCG)as the serum markers. From May 2004 to September 2006, 11 centers participated in the collection and analysis of maternal serum AFP and free β-hCG between 14 and 20+6 weeks of pregnancy. The screening results were calculated using the standard algorithm based on the standard database provided with the analytic software. Patients with an increased risk of Down's syndrome pregnancy (≥1/270) were offered genetic anmiocentesis. Outcomes of all pregnancies were obtained.Results A total of 66 132 singleton pregnancies were included in the study. The median maternal age was 27 years. At a cut-eft of 1 in 270, the detection rate (DR) based on a Caucasian database was 72% corresponding to a false positive rate (FPR) of 5%, and the DR based on the Chinese database was raised to 76% corresponding to an FPR of 5%. Conclusion The double-marker test using AFP and free β-hCG is an effective screen strategy for second-trimester detection of fetal Down's syndrome in mainland China. Ethnic variance exists between the Caucasian and Chinese populations. The accuracy of screening is increased by the use of race-specific medians.