698: Telomeres in trisomy 21 amniocytes

698: Telomeres in trisomy 21 amniocytes

Fetus Diabetes, etc www.AJOG.org GAPDH amounts were significantly increased in the plasma of obese vs lean women. These changes were associated with ...

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Fetus Diabetes, etc

www.AJOG.org GAPDH amounts were significantly increased in the plasma of obese vs lean women. These changes were associated with an increased rate of apoptosis in placentas of obese vs. lean women (p⬍0.005). CONCLUSION: Maternal obesity in pregnancy is associated with increased circulating fetal and total DNA levels, which reflect an increased placental size at term. The increased rate of trophoblast apoptosis, with subsequent shedding of placental derived microparticles, has pro-inflammatory properties in the maternal circulation. We hypothesize that increased cf DNA in maternal circulation represents a link between the inflammatory environment and the higher fetal adiposity in obese women. 0002-9378/$ – see front matter • doi:10.1016/j.ajog.2009.10.714

698 Telomeres in trisomy 21 amniocytes Rivka Sukenik Halevy1, Tal Biron-Shental2, Lilach GoldbergBittman3, Reuven Sharony1, Moshe Fejgin1, Aliza Amiel4 1

Tel-Aviv University, Meir Medical Center, Department of OB-GYN, Genetic Institute, Kefar Saba, Israel, 2Tel-Aviv University, Meir Medical Center, Department of OB-GYN, Kefar Saba, Israel, 3Bar-Ilan University, Meir Medical Center, Genetic Institue, Kefar Saba, Israel, 4Bar-Ilan University, Meir Medical Center, Genetic Institute, Kefar Saba, Israel

OBJECTIVE: Functional telomeres are essential for the normal segregation and maintenance of chromosomes during cell division. Telomeres shorten with each cell replication. Telomerase is an enzyme complex that elongates telomeres. One of its components is the human telomerase RNA (hTR), encoded by the TERC gene, which serves as the RNA template for the addition of telomeric repeats. Individuals with trisomy 21 have an increased risk of developing malignancies and premature dementia. They have higher rate of telomeres loss and it has been shown that telomeres are shorter in individuals with DS and dementia. The aim of the study was to asses telomeres length, and hTERC gene copy number in amniocytes of DS conseptions compared to amniocytes from normal pregnancies. STUDY DESIGN: Quantitative fluorescence-in-situ protocol (Q-FISH) was used to asses telomeres length in amniocytes cultured from trisomy 21 conceptions (7 cases) and from normal pregnancies (8 cases). The quantification was conducted using a novel computer analysis software. We used FISH in order to asses the percentage of cells with additional copies of hTERC in the trisomy 21 group (10 cases) and in the control group (8 cases). RESULTS: Immunoflurocence intensity, which represents telomeres length, was lower in amniocytes from trisomy 21 conceptions as compared to the control group. The number of cells with additional genomic copies of hTERC (on the same chromosome and on a different chromosome) was signifficantly higher in the trisomy 21 group (p value ⬍0.01). CONCLUSION: Telomeres in amniocytes from trisomy 21 conceptions are shorter then telomeres in amniocytes from normal pregnancies. The copy number of hTERC is higher in Trisomy 21 amniocytes. This observation could be one of the cytogenetic parameters which represents a state of genetic instability which correlates both to the risk of developing dementia and to the predisposition for malignancies in individuals with trisomy 21. 0002-9378/$ – see front matter • doi:10.1016/j.ajog.2009.10.715

699 First trimester screening versus diagnostic testing; how important is prenatal counseling in the decision-making process?

rollment in the study. Enrolled women were mailed questionnaires prior to genetic counseling to assess their intentions to undergo first trimester screening and/or invasive diagnostic testing. Participants then underwent group and individual counseling with genetic counselors, which included education regarding first trimester screening versus invasive testing options. Data on testing choices were collected, and the effect of genetic counseling on choices was assessed. RESULTS: 155 women were enrolled. Prior to genetic counseling, 142 (92%) women stated they wanted definitive information regarding presence of a genetic abnormality, and 19 (12%) planned to undergo invasive diagnostic testing. After genetic counseling, 17 (89%) of the 19 who planned an invasive procedure opted for non-invasive screening instead. 148 women who planned to undergo first trimester screening proceeded with screening following counseling. CONCLUSION: First trimester genetic counseling altered patients’ preliminary plans for invasive diagnostic testing but not for non-invasive screening. Most patients indicated they would like definitive genetic information but only a minority elected invasive diagnostic testing without prior screening. Genetic counseling, or patient education, appears to be an important component of first trimester prenatal testing. 0002-9378/$ – see front matter • doi:10.1016/j.ajog.2009.10.716

700 Uneven distribution of gender in fetuses with mild and moderate increase of NT Manal Eldaouk1, Barak Rosenn1, Lois Brustman1, Oded Langer1, Andrzej Lysikiewicz1 1

Roosevelt Hospital - Columbia University, New York, New York

OBJECTIVE: To describe the ratio of male to female gender distribution

in fetuses with mild ( 2.5 ⫺2.9 ) and moderate ( 3.0 ⫺3.5 ) increase of nuchal translucency (NT). STUDY DESIGN: 5109 patients had first trimester NT screening. The study group consisted of the 74 patients with intermediate NT measurements (2.5 ⫺3.5mm). In this group, fetal gender was ascertained by karyotype or by neonatal examination at birth. Gender distribution in the mildly (2.5-2.9mm) and moderately (3.0-3.5) increased NT subgroups was compared with the general population. RESULTS: Overall male:female ratio in the study group was 3.8:1 as compared to the 1.04:1 ratio in the general population in NYC (p ⫽0.0001). Two patients had spontaneous abortion, both females, and 2 patients were lost to follow up. 63 patients delivered healthy infants with a male:female ratio of 51:12. Among the 7 voluntary terminations of pregnancy, male:female ratio was 6:1 (see Table). Male:female ratio was higher in the mildly increased NT subgroup compared to the moderately increased subgroup (p⫽0.03). CONCLUSION: Male to female ratio among fetuses with an intermediately increased NT measurement is higher than in the general population, particularly among those with mildly increased NT. We speculate that the intermediately increased NT in male fetuses may result from delayed myocardial maturation during early development of male fetuses with reduced flow in the ductus venosus leading to fluid retention and increased NT. Additionally, testosterone may also contribute to this phenomenon, retarding the barrier development in fetal skin. Increased NT and fetal gender

Amy Wong1, Yair Blumenfeld1, Deirdre Lyell1, Kelly Ormond1, Jane Chueh1 1

Poster Session V

Stanford University, Stanford, California

OBJECTIVE: To determine the effect of prenatal genetic counseling on women’s decisions regarding first trimester screening versus invasive diagnostic testing. STUDY DESIGN: Pregnant women referred for routine prenatal counseling in the first trimester at the Lucile Packard Children’s’ Hospital (Stanford University) Perinatal Diagnostic Center were offered en-

Outcome M - F

NT 2.5-2.9 mm(n 45)

NT 3.0-3.5 mm(n 29)

NORMAL

M 36 F 4

M 15 F 6

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Aneuploidy/abnormal M3F0 M3F3 .......................................................................................................................................................................................... SAB M0F1 M0F1 .......................................................................................................................................................................................... LOF 1 1 .......................................................................................................................................................................................... 0002-9378/$ – see front matter • doi:10.1016/j.ajog.2009.10.717

Supplement to DECEMBER 2009 American Journal of Obstetrics & Gynecology

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