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Trimester Screening (trimester + screening)

Distribution by Scientific Domains
Medical Sciences33%

Kinds of Trimester Screening

  • first trimester screening
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    Selected Abstracts

    Trisomy 16 detected by first trimester screening

    PRENATAL DIAGNOSIS, Issue 12 2009
    F. Petracchi
    No abstract is available for this article. [source]

    Uptake of prenatal screening for chromosomal anomalies: impact of test results in a previous pregnancy

    PRENATAL DIAGNOSIS, Issue 13 2002
    Kevin Spencer
    Abstract Aim To assess whether the uptake of prenatal screening for trisomy 21 in a subsequent pregnancy is influenced by being classified in the ,increased risk' or ,not at increased risk' group in the first pregnancy. Setting District General Hospital Maternity Unit. Methods Amongst a group of women attending for maternity care at this hospital, the maternity records were examined to find women having at least two pregnancies. Any prenatal screening record for each pregnancy was retrieved from the prenatal screening database. Prenatal screening for trisomy 21 was by a combination of maternal serum ,-fetoprotein (AFP) and free ,-human chorionic gonadotrophin (,-hCG) in the second trimester and by maternal serum free ,-hCG and pregnancy-associated plasma protein-A (PAPP-A) and fetal nuchal translucency (NT) thickness in the first trimester. Women were stratified according to their trisomy 21 risk into an ,increased risk' group (1: <250 in the second trimester and 1: <300 in the first trimester) or ,not at increased risk' group based on their first pregnancy. In a second pregnancy, the records were examined to see if the mother accepted prenatal screening in the second pregnancy. The rate of acceptance of screening in a subsequent pregnancy, depending on whether ,at increased risk' or ,not at increased risk' in the first pregnancy, was examined using chi square tests. Results In the second trimester study, 4601 women were identified with two pregnancies during the study period. Of these, 4559 women had prenatal screening in a subsequent pregnancy. Initially, 273 women were identified in the high-risk group, and of these 252 (92.3%) elected to have prenatal screening in a subsequent pregnancy. This compared with 4307 of 4328 (99.5%) women in the low-risk group. In the first trimester study, 1077 women were identified with two pregnancies during the study period. Of these, 1072 had prenatal screening in a subsequent pregnancy. Initially, 60 women were identified in the high-risk group, and of these 56 (93.3%) elected to have prenatal screening in a subsequent pregnancy. This compared with 1016 of 1017 (99.9%) in the low-risk group. Statistically, there was no difference between the rate of declining prenatal screening in a second pregnancy amongst those in the high-risk group in a first pregnancy or those in the low-risk group (p = 0.429 for second trimester screening and p = 0.794 for first trimester screening). Similarly, no difference could be demonstrated between rates when screening in the first or second trimester (p = 0.961) for those in the high-risk group. Conclusion Despite the understandable anxiety associated with being identified in the high-risk group (as a false positive finding) in a previous pregnancy, this did not seem to deter women from accepting prenatal screening in a subsequent pregnancy. Copyright © 2002 John Wiley & Sons, Ltd. [source]

    Comparison and integration of first trimester fetal nuchal translucency and second trimester maternal serum screening for fetal Down syndrome

    PRENATAL DIAGNOSIS, Issue 8 2002
    Yung Hang Lam
    Abstract Background It is uncertain whether first trimester nuchal translucency (NT) is more effective than the well-established second trimester serum screening for fetal Down syndrome or whether their combination works best. We report data from a large multicentre non-interventional trial in which all subjects underwent both first and second trimester screening. Methods All women who attended the obstetric clinic before 15,weeks' gestation were recruited. An ultrasound examination was performed at 10 to 14,weeks to measure the NT. The nuchal measurements were not acted upon unless the fetus showed gross features of hydrops fetalis. All women had serum alpha-fetoprotein (AFP) and human chorionic gonadotrophin (hCG) assay at 15 to 20,weeks. The Down syndrome risk assigned by serum screening was disclosed and amniocentesis was offered if this assigned risk was ,1:250 or if the women were 35,years and older. The efficacy of different combinations of screening markers was compared. Results Between January 1997 and August 2000, 17 590 women were recruited (19% ,35,years old). After excluding subjects who miscarried, defaulted the serum test and other reasons, 16 237 pregnancies were analysed. Of these, 35 pregnancies were affected by Down syndrome (2.2 cases per 1000 pregnancies). At a false-positive rate of 5%, the detection rate of Down syndrome by NT alone, NT and age, serum hCG, AFP and age, and NT, hCG, AFP and age were 61%, 69%, 73% and 86%, respectively. Conclusion Integration of NT and second trimester serum AFP and hCG assay yielded the best screening efficacy for Down syndrome. Copyright © 2002 John Wiley & Sons, Ltd. [source]

    First trimester screening for Down syndrome and assisted reproduction: no basis for concern

    PRENATAL DIAGNOSIS, Issue 7 2001
    K. R. Wøjdemann
    Abstract In pregnancies obtained after assisted reproduction the false-positive rate of second trimester Down syndrome (DS) screening is increased by 1.5,3-fold. This may cause an increase in the number of amniocenteses and the fetal loss rate. The present study for the first time examined whether assisted reproductive technologies affect the results of first trimester screening. The markers PAPP-A, free ,-hCG and the nuchal translucency (NT) thickness were examined at 12,14 weeks' gestation. Screening markers in 47 in vitro fertilisation (IVF), 63 ovulation induction (OI) and 3026 spontaneously conceived singleton pregnancies were compared. The MoM (multiples of the median) value in the IVF pregnancies was 1.02 (95% CI: 0.85,1.22) for PAPP-A, 1.14 (95% CI: 0.95,1.37) for ,-hCG and 0.97 (95% CI: 0.89,1.05) for NT; the MoM value in the OI pregnancies was 0.89 (95% CI: 0.76,1.05) for PAPP-A, 1.08 (95% CI: 0.93,1.25) for ,-hCG and 1.02 (95% CI: 0.95,1.11) for NT. The first trimester marker values in assisted reproductive pregnancies and spontaneously conceived pregnancies were not significantly different. Estimated false-positive rates for a risk cut-off of 1:400 varied from 4.7% in IVF pregnancies to 5.1% in OI pregnancies. Therefore the false-positive rate in Down syndrome screening should be independent of the method of conception. Copyright © 2001 John Wiley & Sons, Ltd. [source]

    Perinatal outcome in fetuses with extremely large nuchal translucency measurement

    AUSTRALIAN AND NEW ZEALAND JOURNAL OF OBSTETRICS AND GYNAECOLOGY, Issue 3 2009
    Fergus SCOTT
    Background: Studies have suggested that an entirely normal outcome is likely when the nuchal translucency (NT) measurement is very large and the karyotype, morphology and echocardiography scans are normal. Recently this has been questioned as it is based on very small numbers. Aim: Assess the outcome of pregnancies with an NT measurement of 6.5 mm or greater. Methods: Audit of a large first trimester screening program. Results: Over the ten years to 2006, 76 813 patients underwent first trimester screening, with 120 having an extremely large NT. Thirty-one cases had normal karyotypes, of which there were four sets of twins that demised. Six cases miscarried and ten were terminated, some with morphological abnormalities. Eight cases were still alive for the morphology scan, with the only abnormality being mild pyelectasis in one case. At birth, three cases were normal and another three cases had a good outcome. Two cases had coarctation of the aorta and a good outcome. One case had Noonan's syndrome, another had cerebral palsy and the case with pyelectasis had hydronephrosis, dilated ureters and some contractures. Conclusions: When the karyotype and morphology scan are normal, the outcome is often good in spite of an extremely large NT. However, even a subtle ultrasound anomaly can indicate a genetic syndrome and echocardiography cannot exclude mild cardiac abnormalities. [source]

    The use of nuchal translucency measurement and second trimester biochemical markers in screening for Down's Syndrome

    BJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 10 2001
    G.D. Michailidis
    Objective To assess the effectiveness of antenatal screening for trisomy 21 by first trimester sonography followed by second trimester biochemical screening. Design Retrospective five-year review. Setting Maternity unit of a university hospital. Population An unselected group of 7447 pregnant women who had a first trimester scan and nuchal translucency measurement in our unit after January 1995 and had an estimated date of delivery before 1 January 2000. 11.9% were , 37 years old. A subgroup (n=4864) also had second trimester biochemical testing by alpha-fetoprotein and free ,-human chorionic gonadotrophin. Main outcome measures Prenatal and postnatal diagnosis of trisomy 21. Results There were 23 fetuses affected with trisomy 21. The overall prenatal detection rate was 87% (20/23; 95% CI 66% to 97%) and we performed invasive procedures in 8.5% of our population. First trimester sonography identified 74% (95% CI 51.6% to 89.8%) of affected fetuses. Second trimester biochemical screening detected half of the fetuses with trisomy 21 which were missed by first trimester screening, increasing the sensitivity to 90.5% (19/21; 95% CI 69.6% to 98.8%) for an invasive procedure rate of 4.2% performed in screened positive women. However, the positive predictive value of the biochemical test was very low (0.5%). In screen negative women, karyotyping for advanced maternal age did not detect any affected fetuses. Conclusion First trimester nuchal translucency measurement is an effective screening test for the prenatal detection of fetuses with Down's Syndrome. Although the measurement of biochemical markers in the second trimester can detect additional affected fetuses this may be outweighed by the delay in diagnosis, the extra visits and cost so that the right time for biochemical screening is most likely to be in the first trimester. [source]