Comparison of second-trimester maternal serum free-beta-human chorionic gonadotropin and alpha-fetoprotein between normal singleton and twin pregnancies: a population-based study / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The second-trimester maternal serum screening in twin pregnancy is still controversial, as the serum marker levels in twins are not as clear as those in singletons. This study aimed to evaluate the relationship between the levels of the second-trimester maternal serum free beta-human chorionic gonadotropin (free beta-HCG) and alpha-fetoprotein (AFP) in normal twin and singleton pregnancies and to estimate feasible analysis methods for utilizing these markers in second trimester screening for twin pregnancy.</p><p><b>METHODS</b>On the basis of a prospective population-based study of second-trimester maternal serum screening, the concentrations of maternal serum AFP and free beta-HCG of 195 normal twin pregnancy and 26,512 singleton controls at gestational weeks 15 to 20 were measured by time-resolved fluoroimmunoassay in one laboratory. The levels of markers were compared between the twins and singletons using weight-correction and gestational age-specific model.</p><p><b>RESULTS</b>According to the research protocol, 95 communities were randomly sampled, which covered the whole Jiangsu province, the east of China. A total of 26 803 pregnant women (98%), from the target population accepted prenatal screening for maternal serum AFP, beta-HCG detection, and all babies were followed up for at least six months. There were 197 (0.73%) twin pregnancies, of which one case had fetal trisomy 18, and one case with fetal anencephaly. The others were normal twin pregnancy. From a total enrollment of 26 803 women participants, 26 512 women with normal singleton pregnancies were selected as the model controls. The other 291 pregnancies, including trisomy 21, neural tube defect (NTD), trisomy 18, and other fetal abnormalities, were excluded. No significant differences were found in the medians of gestational age-specific maternal serum free beta-hCG and AFP in normal twin pregnancy comparing with twice those in model controls with the exception of the medians for free beta-hCG during the 16th gestational week (P = 0.012).</p><p><b>CONCLUSION</b>The weight-correction and gestational age-specific levels of Chinese Han population maternal serum free beta-hCG and AFP in normal twins were twice the levels as those in the singleton controls during the 17-19 gestational weeks.</p>

A study on population-based prenatal screening and diagnosis of Down's syndrome in Jiangsu province / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To screen and diagnose Down's syndrome during mid-term pregnancy to reduce the number of babies with Down's syndrome.</p><p><b>METHODS</b>With the multi-level of stratified cluster sampling, twenty thousand and eight hundred and three women at 15-20 weeks gestation were screened by maternal serum AFP and beta-hCG using the time resolved fluoroimmunoassay (TRFIA). Then the screened high-risk women were diagnosed by amniocentesis, cell culture and chromosome analyses. The born children were diagnosed by follow-up and peripheral blood chromosome analyses.</p><p><b>RESULTS</b>Six fetuses were diagnosed by serum screening and amniotic fluid chromosome analyses, and 3 born children were diagnosed by follow-up and peripheral blood chromosome analyses. Nine cases of Down's syndrome were detected in total, with the positive prenatal screen rate being 67% (6/9).</p><p><b>CONCLUSION</b>The prenatal screening and diagnosis can reduce the birth of Down's syndrome patients and improve the population quality. However, the diagnosis accuracy still needs to be improved to further reduce the false negative rate and prevent misdiagnosis.</p>

Evaluating the applicability of MoM in second trimester maternal serum to screening for Down's syndrome in Jiangsu province / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study the applicability of MultiCalc software to prenatal screening of Down's syndrome in Jiangsu province, China.</p><p><b>METHODS</b>The gestational age-specific median of maternal serum marker was calculated by means of regression method. Regression functions for adjustment of Multiple of the Median (MoM) by weight were established for our own population.</p><p><b>RESULTS</b>Before the adjustment by weight, the average level of alpha fetal protein(AFP) was 16% higher and the free beta-human chorionic gonadotrophin (beta-hCG) was 14% higher than those of the Caucasian in MultiCalc software respectively. But when the AFP and free beta-hCG results were converted to weight-adjusted MoM levels, the values were 0.99 and 1.02 respectively. The median of MoM of AFP and the free beta-hCG were 1.00 through the regression model of gestational age and weight adjustment.</p><p><b>CONCLUSION</b>There was no difference of average weight-adjusted MoM levels between the Jiangsu population and the Caucasian, and the MultiCalc software was applicable to maternal serum screening for Down's syndrome of Jiangsu.</p>

Effects of chlorotriptolide and triptonide on chromosome aberration and micronuclei of bone marrow cell in male rats / 中华男科学杂志

<p><b>OBJECTIVES</b>To observe the effects of chlorotriptolide (T4) and triptonide (T7) on the chromosome aberration and micronuclei rates of bone marrow cell in male SD rats.</p><p><b>METHODS</b>Antifertility doses of T4[80 micrograms/(kg.d)] or T7[317 micrograms/(kg.d)] were given to male rats per OS for 10 weeks. Bone marrow slides were then prepared and compared with the controls.</p><p><b>RESULTS</b>The chromosome aberration and micronuclei rates were not significantly different from those of the controls (P > 0.05).</p><p><b>CONCLUSIONS</b>The results were in accordance with our previous reports about the effects of T4 and T7 on the chromosome aberration and micronuclei rates of rat spermatogenic cells. At the antifertility doses, T4 and T7 did not show a mutagenic effect.</p>