The training of clinical thinking ability is the key point of obstetrical teaching to medical students in eight-year program.Obstetrical department of the third affiliated hospital of Sun Yat-sen university has put forward specific methods of SP inquiring and PBL case analysis teaching.The well-designed teaching methods have an active role in the training of case history collecting ability,diagnosing and treating ability to medical students in eight-year program.

Objective To investigate the antenatal influencing factors associated with birth weight of twins and the risk factors for the occurrence of discordant twins. Methods Totally, 834 twins delivered at the Third Affiliated Hospital from January 2000 to December 2009 and the First Affiliated Hospital of SUN Yat-sen University, from January 2000 to June 2009, were recruited in the study. The diagnosis criteria of discordant twins was intrapair birth weight difference more than 25 %.Antenatal factors on birth weight were retrospectively investigated among twins and discordant twins respectively with Logistic analysis. Results (1) There were several factors associated with birth weight of twins, including maternal age, conceptive style, chorionicity, gestational diabetes mellitus and placental cord insertion ( P = 0. 021, 0. 000, 0. 000, 0. 012 and 0. 017, respectively). While hypertensive disorder in pregnancy, parity and fetal gender differences were not associated with the birth weight of twins (P＞0.05). Hypertensive disorder in pregnancy (OR=2. 600, 95% CI:1. 566-4. 316) and monochorionicity (OR= 1. 833, 95% CI: 1.010-3. 582) were risk factors of discordant twins. All 834 twin pregnancies were divided into 4 groups according to materal age, ＜25 yrs (n=69), 25-30 yrs (n=312), 30-35 yrs (n=325) and ≥35 yrs (n=128). The average birth weight of twins were (2205±483) g, (2347±406) g, (2381±439) g and (2352±455) g. Significant difference was found bewteen every two groups (P＜0. 05) except that between the 30-35 yrs and ≥35 yrs group (P＞0.05). Among twins of different gender (n=270), the average birth weight of boys and girls were (2416±-514) g and (2322±488) g, and that of female twins (n=272) and male twins (n=292) were (2301±418) g and (2381±428) g. Significant difference was shown between every two groups (P＜0.05) except that between the male twins and male fetus of twins of different gender (P＞0.05).Conclusions The fetal birth weight of twins decreases remarkably when maternal age ＜25, or monochorionicity twins, or complicated with marginal or velamentous placental cord insertion or female pairs.However, birth weight of twins would increase if the pregnancy conceived by assisted reproductive technology or complicated with gestational diabetes mellitus. Twin pregnancy complicated with hypertensive disorder in pregnancy or monochorionicity should alert the clinicians of discordance twins.

[ ABSTRACT] AIM:To evaluate the clinical application of single nucleotide polymorphism array ( SNP array) in prenatal diagnosis for screening the abnormality of women with Down’ s syndrome ( DS) .METHODS:The amniotic fluid samples ( n=312) collected by amniocentesis for the DS screening abnormality women were tested by karyotyping and SNP array analysis, respectively.The findings of karyotyping and SNP array analysis were compared.RESULTS:Two cases of trisomy 21 were identified by karyotyping and SNP array analysis, but SNP array analysis failed to identify 6 cases of chro-mosome balanced structural rearrangement.SNP detected 176 cases copy number variants ( CNVs) in 303 cases normal karyotype were detected by SNP, including 106 benign CNVs, 61 variants of unknown significance (VOUS), 9 de novo CNVs, and none of them was pathogenic.The distribution difference of CNVs in DS screening positive group and DS screening positive plus advanced maternal age group was not statistically significant ( P>0.05) .Furthermore, we reported 14 kinds of CNVs for the first time in population.CONCLUSION:SNP array can further assure chromosome microdupli-cation/microdeletion.In normal karyotype fetus of prenatal diagnosis, SNP can detect some clinical significant CNVs.

AIM:To explore the characteristics of hepatitis B virus S gene mutation in the vertical transmission after active and passive vaccination .METHODS:Fifteen cases of immunoprophylaxis failure were enrolled in the study . HBV S gene (including pres-S and S) from the mothers, newborns before active and passive vaccination and 7-month-old infants with immunoprophylaxis failure were detected by PCR amplification .The characteristics of HBV S gene mutation were compared among the 3 groups.RESULTS: The genotype of HBV in the newborns and the infants was the same as that in the mothers .The frequencies of mutation in the 2 fragments of the HBV S gene had no significant difference between the 3 groups.The homology tree model based on HBV S gene was analyzed in the 3 groups, in which every group had their own cluster.There were 15 different mutation sites between 7 pairs of mothers and newborns .There were 3 different muta-tion sites between 3 pairs of newborns and infants (nt273A→A/G, nt512C→C/T and nt1139C→A), among which the first 2 were located in the S gene region but not in the “a” determinant , and the latter was located in the overlap region of S and X genes .There were 25 different mutation sites between 9 pairs of mothers and infants , but only 1 case had a differ-ent mutation site between the mother , newborn and infant .CONCLUSION: The HBV species in newborns and infants with immunoprophylaxis failure were transmitted from the mothers .The mutations in the HBV S gene with immunoprophy-laxis failure happened before and after active and passive vaccination , mainly before vaccination .The relationship between HBV S gene mutations and immunoprophylaxis failure should be further explored .

AIM:To establish a kind of simple and efficient method for cell-free fetal DNA ( cff-DNA) enrich-ment and to investigate its range of applications and the advantages and disadvantages.METHODS:(1) The single nucleo-tide polymorphisms( SNPs) , which linked to paternalβ-thalassemia mutations, were screened.We analyzed the contact be-tween the SNPs inβ-thalassemia gene ( HBB gene) and haploid type by the Haploview software, and then selected these close SNPs which have higher heterozygosity with the HBB gene.(2) We selected 4 cases of different β-thalassemia muta-tions with their husband, and then we used TT-FAST-COLD-PCR to enrich the IVS-II-654 mutations in maternal plasma.If the IVS-II-654 mutation was not detected, we detected the SNP which linked to the IVS-II-654 mutation.Similarly, we used TT-FULL-COLD-PCR to enrich the CD41-42 mutations in the maternal plasma.At the same time, we used the conventional PCR to enrich CD41-42 mutation and IVS-II-654 mutation in the maternal plasma.RESULTS:(1) Nine cases of the SNP ( rs7480526) linked to the mutation at IVS-II-654 in HBB gene, and 11 cases of the SNP ( rs10768683) linked to the muta-tion at CD41-42 in HBB gene were detected.( 2 ) We detected 1 case who inherited the paternal β-thalassemia mutation (IVS-II-654).We did not directly detect patermal IVS-II-654 mutation in maternal plasma, but detected the SNP linked to the IVS-II-654 mutation in the other case and had 100%detection, and 2 cases inherited the paternal β-thalassemia muta-tions (CD41-42) in the maternal plasma by TT-FULL-COLD-PCR and had 100%detection.However, we detected nothing by conventional PCR.CONCLUSION:TT-COLD-PCR is applicable to enrich cell-free fetal DNA in maternal plasma and is a method in the field of noninvasive prenatal diagnosis.

OBJECTIVE: To investigate the effect of ginseng total saponins (GTS) on expression of nerve growth factor in rat with polycystic ovaries. METHODS: A total of thirty rats were randomly divided into normal control group, untreated group and GTS group. Polycystic ovaries were induced by a single intramuscular injection of 4 mg estradiol valerate (EV) in rats of the untreated group and GTS group. The rats in the GTS group were administered 50 mg/kg GTS every other day by intraperitoneal injection for 30 days after the EV injection. The expressions of NGF in the ovaries, pituitary and hippocampus were observed by method of immunohistochemistry. RESULTS: Comparison with the normal control group revealed that the expressions of NGF in ovaries, pituitary and hippocampus of rats in the untreated group were increased (P<0.05). The ovarian morphology of the GTS group was almost as normal as that of the normal control group. As compared with the untreated group, the expression of NGF in ovaries of the rats in GTS group was obviously decreased (P<0.05), while the expression of NGF in pituitary and hippocampus showed on difference. CONCLUSION: GTS can decrease the expression of NGF in ovary tissue in rats with polycystic ovaries induced by EV, which may be its mechanism in lessening the polycystic ovary.

Protocol design and implementation are important steps for clinical trial . This article discussed key issues on effect of live birth rate by polycystic ovary syndrome ( PCOS ) treatment with acupuncture combined with clomiphene citrate in the randomized controlled trial ( RCT ) process . For example , the trial designs ( i . e . , trial design characteristics , selection of featured therapeutic effect index ) , clinical trial implementation ( i . e . , or-ganization construction , quality control , and etc . ) . This summarization provided references for the design and implementation of clinical trial plan .

AIM:Toinvestigatewhetherandhowhumanchorionicgonadotropin(HCG)treatmentameliorates endometriosis in the endometriotic rat model .METHODS:The rat model of endometriosis was established and the model rats were divided into 4 groups.The rats in HCG groups were treated with 19.4, 25.8 and 51.6 IU/100 g of HCG every day (low-dose HCG, medium-dose HCG and high-dose HCG, respectively).The rats in control group were treated with 0.9%NaCl.After 15 days (3 estrous cycles), the ectopic lesion volume and ultrastructural characteristics in eutopic and ectopic endometria were investigated .RESULTS: After HCG treatment , the volume of endometriotic lesions was signifi-cantly smaller than that before treatment .Numerous and mitochondrial , endoplasmic reticulum and ribosomes were ob-served in the cytoplasm of eutopic and ectopic endometrium before treatment .After treatment , some cell structures were not clear , and mitochondrial cristae decreased or disappeared partly .Some cells were densed and shrinkage , autophagosome in cytoplasm increased , and mitochondria and endoplasmic reticulum swelt .CONCLUSION:HCG therapy appears to be an effective treatment for endometriosis in rats attributed to its influence on cell metabolism dysfunction of eutopic and ectopic endometria .

Objective To investigate the relationship of insulin resistance and secretion during late pregnancy in women with glucose intolerance.Methods Immunoenzymetric assay was used to measure the fasting serum insulin levels in 122 pregnant women which including of 36 pregnant women with gestational diabetes mellitus(GDM),34 pregnant women with gestational impaired glucose tolerance(GIGT),and 52 pregnant women with normal glucose tolerance(NGT).The fasting plasma glucose levels were measured by glucose oxidase method.The insulin sensitivity index(ISI) and islet secretive function index(IFI) were compared between the three groups.Results ISI had an increasing trend from NGT group,GIGT group to GDM group(P

Objective To investigate the intrauterine growth characteristics of twins and birthweight discordant twins (discordant twins ).MethodsTotal of 1010 twin pregnancies (2020 fetuses) with complete delivery records from the Department of Obstetrics and Gynecology,the First and Third Affiliated Hospital of SUN Yat-sen University between January 1,2000 and July 31,2010 were studied retrospectively.One handred and ninteen cases (238 fetuses) with intrapair birthweight difference ≥25％ were determined as the discordant twins group,and the other 891 cases (1782 fetuses) with intrapair birthweight difference ＜ 25％ were identified as the concordant twins group.The singleton control group included 4042 singleton pregnancies in the same period.Results ( 1 ) Comparison of clinical data between the twins groups:the birthweight of larger-twin,smaller-twin and intrapair birthweight difference in the discordant twins group and the concordant twins group were ( 2090± 827 ) g,( 1392 ± 592 ) g,( 33.9 ±9.3 ) ％,and ( 2408 ± 543 ) g,( 2191 ± 505 ) g,( 8.9 ± 6.5 ) ％,respectively,with significant differences (P＜0.01).The incidence of discordant twins was 11.78％ (119/1010).Compared with the concordant twins group,the discordant twins group bad higher proportion of monochorionic twins,and higher prevalence of pregnancy complications such as late miscarriage,abnormal umbilical insertion,twin-twin transfusion syndrome and hypertensive disorders in pregnancy ( P ＜ 0.05 ).( 2 ) The characteristics of twin birthweight distribution:① In all the 2020 twins,80.05％ (1617/2020) fetuses had birthweight below the 50th percentile of the singleton control group,while 23.71％ (479/2020) feeuses got birthweight below the 10th percentile of the singleton control group.② After 19th gestational week,the 50th and 90th percentile of all twins' birthweight were lower than those of singletons.After 38th gestational week,the birthweight of singletons kept increasing and reached its peak at 41 th week,while the birthweight of twins reached its peak at 38th week,followed by a decline at 39 weeks,which was even lower than the 10th percentile of the singleton control group.③ The distribution of birthweight of larger- and smaller-twin in the discordant twins group:65 (54.6％,65/119) larger-twins and one (0.8％,1/119) smaller-twin had birthweight above the 50th percentile of all twins,while 5 (4.2％,5/119) larger-twins and 97 ( 81.5％,97/119 ) smaller-twins got birthweight below the 10th percentile of all twins.Conclusions ( 1 ) The patterns of birthweight curves for each gestational week are different between twins and singletons.In order to evaluate the growth of twins, birthweight reference for twins shoull be employed.( 2 ) According to the reference of twins birthweight,the most discordant twins are complicated with fetal growth restriction at least in one twin.