DETECTION OF STRAND BREAKS OF DNA IN HUMAN EARLY CHORIONIC VILLUS CELLS INDUCED BY DIAGNOSTIC ULTRASOUND USING ^(32)P-LABELED ALU HYBRIDIZATION

Objective To explore if strand breaks of DNA in human early chorionic villus cells in uterus were induced by diagnostic ultrasound and to evaluate the method used for detection of single-stranded breaks and double-stranded breaks in human DNA. Methods 60 normal pregnant women aged 20-30, who underwent artificial abortion during 6-8 weeks of gestation, were randomly divided into 2 experimental groups: All 30 cases were exposed to diagnostic ultrasound in uterus for 10 minutes, and 24 hours later chorionic villi were extracted; the other 30 cases were taken as the control group. Single-stranded DNA and double-stranded DNA in villus cells in all cases were isolated by the alkaline unwinding combined with hydroxylapatite chromatography, and were quantitatively detected using 32 P-labeled Alu probe for dot-blotting hybridization. Results There was no significant difference in quantity and percentage in single-stranded DNA and double-stranded DNA between 2 groups (P>0.05). 32 P-Alu probe could only hybridize with human DNA, and could detect DNA isolated from as few as 2.5×10 3 chorionic villus cells and 0.45ng DNA in human leukocytes. Conclusion The results suggested that there were no DNA strand damages in human chorionic villus cells when the uterus was exposed to diagnostic ultrasound for 10 minutes. The method,^(32)P-Alu probe for dot-blotting hybridization, was even more specific, sensitive and accurate than conventional approaches.

Outcome of 1355 consecutive transabdominal chorionic villus samplings in 1351 patients

Background The true risk of choronic villus sampling （CVS） is poorly defined. The objective of this study was to review the clinical outcome of transabdominal CVS performed in a university teaching unit, with an emphasis on the complication rate.Methods A comprehensive audit database was maintained for 1351 pregnant women, including 17 sets ot twin pregnancies, who had a CVS. Details and outcome of all CVSs made in the unit between May 1996 and May 2004 were reviewed. All CVSs were performed by one of 5 operators using the identical techniques.Results All procedures were performed transabdominally. A total of 1355 CVSs were performed because there were 4 dichorionic twin pregnancies which required 2 punctures. The mean gestation at CVS was （ 11.8 ＋ 0. 7 ） weeks, and 97.3% of the procedures were performed between 11 and 13 completed weeks. The majority （96. 2% ） required only 1 puncture to achieve correct needle placement. The procedure failed to obtain an adequate sample in 4 subjects （0.30%）. A total of 1351 chromosomal studies were requested and there was 1 case （0. 07% ） of culture failure. The results of chromosomal studies were available within 14 days in 36. 7% of the cases and within 21 days in 94. 0%. Overall, 77 chromosomal abnormalities （5.7%） and 5 cases of thalassemia major were detected. Pregnancy outcome was unknown in only 13 singleton subjects （0.96%）. In the remaining 1355 fetuses, there were 76 pregnancy terminations （5.56%）, 10 fetal losses with obvious obstetric causes （0. 73% ）, and 21 potentially procedure-related fetal losses （ 1.54% ）. In the last group, the majority had one or more co-existing obstetric complications. The background fetal loss rate for pregnancies at similar gestational age in the unit was about 0. 8%. Therefore, the procedure-related fetal loss rate was estimated to be at the maximum of 0. 74%.Conclusions In experienced hands, first trimester transabdominal CVS is an accurate and safe invasive prenatal diagnostic procedure. It should be one of the treatment options available to pregnant women who require prenatal genetic diagnosis.

Invasive Procedures for Prenatal Diagnosis in Salmaniya Medical Complex in Bahrain: A Retrospective Cross-Sectional Descriptive Study

Background: Prenatal diagnosis is the process of evaluating the presence of disease or potential disease in the fetus, this enables families to be better prepared before the birth of the baby. There are non-invasive prenatal diagnosis procedures and invasive prenatal diagnosis procedures. The invasive prenatal diagnosis procedures are CVS (chorionic villus sampling) and amniocentesis. The American College of Obstetricians and Gynecologists states that invasive diagnostic testing should be available to all women, regardless of age or risk. Objective: To determine the indications, outcome and results of diagnostic invasive prenatal procedures. Study setting: The obstetrics and Gynecology Department in Salmaniya Medical Complex in Kingdom of Bahrain. Study design: Retrospective descriptive study. Study subjects and Methods: This retrospective descriptive study was conducted on 175 pregnant women who underwent invasive prenatal procedures (CVS and amniocentesis) between January 2013 and December 2018 at SMC in Kingdom of Bahrain. All medical records of the participants were reviewed and entered the study. According to the implemented procedures, medical records were categorized into two chorionic villus sampling (CVS) and amniocentesis groups. The study subject will include indications of the procedures which are advanced maternal age, hematological disorders, genetic disorders, metabolic disorders, abnormal structural findings in fetal ultrasound and previous child with aneuploidy. In addition, the study will address the complications, outcome and results of procedures. Results: About half of our indications of the procedures were due to hematological disorders (47.6%) followed by abnormal structural findings in fetal ultrasound (30.1%) then genetic disorders (15.7%), metabolic disorders (4.8%) and advanced maternal age (1.8%). Regarding complications of the procedure;threatened miscarriage or loss of pregnancy within 3 weeks was (2.3%), amniotic fluid leakage (0.7%), abdominal cramps (0.7%) and Insufficient or contaminated sample (6.2%). Regarding outcome of the pregnancy, our results showed that the loss of pregnancy was (4.8%), intrauterine fetal death or still birth was (13.9%), live birth was (63.9%), preterm delivery was (7.8%), preterm premature rupture of membrane (PPROM) was (1.8%), limbs reduction was (0.0%). Termination of pregnancy outside the country was (7.8%) of chorionic villus sampling and amniocentesis. Conclusion: CVS and amniocentesis are useful outpatient procedures to detect diagnosis or to assess whether a patient is at increased risk of having an affected fetus and that will minimize the psychological impact on the patient and to provide a proper antenatal care to the pregnant women by her obstetrician and follow up to the baby by pediatrician. In this study it was observed that most of the patients who underwent the procedure were couples either carrier or affected to sickle cell disease or Beta thalassemia.

Prenatal cytogenetic diagnosis study of 2782 cases of high-risk pregnant women

Background Prenatal diagnoses are extremely advantageous for pregnant women with high-risk indicators and can help prevent the birth of malformed infants. However, no large-scale statistical study analyzing the correlation between fetal chromosome disorders and abnormal indicators during pregnancy has been done in China. The objectives of this study were to diagnose and analyze fetal chromosome abnormalities, determine the feasibility of the various prenatal test methods and establish diagnostic guidelines for the early, middle, and late trimesters. Methods From January 2004 to May 2009, 2782 pregnant women at high-risk underwent prenatal diagnoses. Categorized data expressed as either actual counts or percentages were analyzed by the chi-square or Fisher＇s exact test. Chorionic villus sampling was performed in the early-trimester （10-12 weeks of gestation）, amniocentesis in mid-trimester （16-28 weeks of gestation）, and umbilical cord blood collection in mid- or late-trimester （16-37 weeks of gestation）. In 51 cases either autopsy samples from intrauterine fetal deaths or placental tissues from aborted fetuses were tested. Results Chromosomal abnormalities were observed in 3.99% （111/2782） of the samples. Overall, the success rate of cytogenetic analysis for high-risk pregnancy groups was 98.17% （2731/2782）. It was significantly less successful when used to analyze data from the chorionic villus sampling compared with that from amniocentesis and umbilical cord blood （P=-0.000）. Abnormal chromosome carriers had the highest percentage of abnormal chromosomes （67.86%） when compared with chromosomal abnormalities in patients with ultra-sonographic ＂soft markers＂ （11.81%）, advanced maternal age （4.51%） and those who had positive serum screening results （P=-0.000）. Conclusions Invasive prenatal diagnostic techniques are feasible tools for confirming fetal chromosomal abnormalities. Abnormal chromosomes detected in one of the parents carrying abnormal chromosome, ultrasound soft markers, advanced maternal age or positive serum screening results were associated with a higher frequency of fetal genetic diseases.

Prenatal Testing or Screening?

Over the past 50 years,the scope and extent of prenatal diagnosis and screening for genetic disorders have improved geometrically.There has been a pendulum like swing from testing to screening back and forth as new technologies emerge.The concurrent developments of cell free fetal DNA analysis of maternal blood has dramatically changed patient’s choices towards screening.However,with the use of array comparative genomic hybridization of fetal DNA that requires diagnostic procedures(Chorionic villus sampling and amniocentesis),much more extensive diagnosis can be obtained.Until noninvasive methods can replicate what can be done with diagnostic procedures there still will be a"price to be paid"for opting for the non-invasive methods.