Chorionic villus sampling and amniocentesis.

Purpose Of Review: The advantages and disadvantages of common invasive methods for prenatal diagnosis are presented in light of new investigations.

Recent Findings: Several aspects of first-trimester chorionic villus sampling and mid-trimester amniocentesis remain controversial, especially fetal loss rate, feto-maternal complications, and the extension of both sampling methods to less traditional gestational ages (early amniocentesis, late chorionic villus sampling), all of which complicate genetic counseling. A recent randomized trial involving early amniocentesis and late chorionic villus sampling has confirmed previous studies, leading to the unquestionable conclusion that transabdominal chorionic villus sampling is safer.

First-trimester fetal reduction to a singleton infant or twins: outcome in relation to the final number and karyotyping before reduction by transabdominal chorionic villus sampling.

Objective: The purpose of this study was to evaluate fetal outcome and maternal complications of multifetal pregnancy reduction to a single fetus or twins. To evaluate safety and efficacy of transabdominal chorionic villus sampling for karyotyping before fetal reduction.

Study Design: Four hundred twenty-four consecutive multiple pregnancies were reduced to twins (255 pregnancies) or a single fetus (169 pregnancies) at 8 to 13 weeks of gestation after transabdominal chorionic villus sampling for fetal karyotyping.

The use of non-physiological conditions to isolate fetal cells from maternal blood.

Fetal cells are always present in maternal blood starting in the first trimester of pregnancy, however a rapid, simple, and consistent procedure for their isolation for prenatal non-invasive genetic investigation is still lacking. Sensitivity and recovery of fetal cells is jeopardized by the minute amount of circulating fetal cells and their loss during the enrichment procedure. We report here a single-step approach to isolate fetal cells from maternal blood which relies on the use of non-physiological conditions to modify cell densities before their separation in a density gradient and in a newly developed cell separation device.

First-trimester prenatal screening for the common 35delG GJB2 mutation causing prelingual deafness.

Objective: This study evaluates the prevalence of 35delG GJB2 mutation, the most common genetic mutation causing prelingual deafness, and its screening feasibility and acceptability in pregnant women undergoing first-trimester CVS for chromosomal abnormality investigation.

Methods: Samples were taken from 5786 pregnant women who requested CVS for chromosomal analysis. The samples were split into two aliquots for chromosome and DNA analysis, respectively.

Early second trimester (13 to 20 weeks) transabdominal chorionic villus sampling (TA-CVS): a safe and alternative method for both high and low risk populations.

Objective: To assess feasibility, effectiveness and risk of prenatal diagnosis by TA-CVS at 13-14 and 15-20 weeks' gestation.

Methods: CVS was performed transabdominally by free-hand single needle insertion technique under continuous ultrasound visualization on 1844 pregnant women, aged 18 to 48, at 13 to 20 weeks' gestation, whose primary indication was chromosomal anomalies and single gene defects in 85% and 15% of cases, respectively Clinical follow-up of women undergoing TA-CVS at 13 to 20 weeks' was prospectively obtained; the population was split in two groups of 13-14 (series B) and 15-20 weeks' (series C) gestation. Statistical evaluation included a group of TA-CVS cases performed at 11-12 weeks (series A).

Outcome of first-trimester chorionic villus sampling for genetic investigation in multiple pregnancy.

Objectives: To evaluate the efficacy of and risk associated with chorionic villus sampling for genetic investigations in multiple pregnancies, and to evaluate the accuracy of the ultrasonographic detection of chorionicity during the first trimester.

Patients And Methods: A total of 198 sets of twins and nine sets of triplets from 10 087 consecutive first-trimester pregnancies undergoing chorionic villus sampling were considered. Gestational age ranged from 7 to 12.

RhD genotyping by quantitative fluorescent polymerase chain reaction: a new approach.

Objective: To develop a new method of RhD/d genotype determination using a quantitative fluorescent PCR (QF-PCR) assay.

Methods: Polymerase chain reaction amplification (PCR) of fragments of exon 7 of both the RHD and RHCE genes was performed from 32 amniotic fluid and 26 chorionic villus samples known to be heterozygous for the RHD gene, 74 peripheral blood samples of RhD-positive blood donors (homozygous or heterozygous) estimated by serologic typing and 24 RhD-negative fetal samples. The number of copies of the RHD gene in RhD-positive samples was determined by comparing the fluorescent intensities of the amplification products specific for the RHD and the RHCE genes.

Rapid detection of chromosome aneuploidies by quantitative fluorescence PCR: first application on 247 chorionic villus samples.

We report the results of the first major study of applying quantitative fluorescence polymerase chain reaction (QF-PCR) assays for the detection of major chromosome numerical disorders. The QF-PCR tests were performed on a total of 247 chorionic villus samples, which were analysed blind, without any knowledge of the results obtained using conventional cytogenetic analysis. The aims of this investigation were to evaluate the detection power and accuracy of this approach by testing a large number of fetal samples and to assess the diagnostic value of each of the chromosome specific small tandem repeat (STR) markers used.

Comparison of urinary free beta (hCG) and beta-core (hCG) in prenatal screening for chromosomal abnormalities.

To evaluate the potential utility of free beta (hCG) and beta-core (hCG) in a prenatal screening protocol for Down syndrome we analysed these markers in dried maternal urine specimens from 163 control, 13 Down syndrome and 5 trisomy 18 pregnancies from 8 to 25 weeks' gestation. All results are reported after normalization for urinary creatinine determined by modified Jaffe reagent assay. The correlation of urinary free beta (hCG) and urinary beta-core (hCG) was 0.

First 10,000 chorionic villus samplings performed on singleton pregnancies by a single operator.

Chorionic villus sampling (CVS) was performed in 10,000 consecutive singleton pregnancies by a single principal operator, working in two institutions. The procedure was performed between 8 and 32 gestational weeks: transabdominal (TA) sampling was carried out in 8479 cases and transcervical (TC) in 1521. Patients were referred for chromosomal risk in 89.

Prenatal cystic fibrosis screening in a low-risk population undergoing chorionic villus sampling for fetal karyotyping.

Screening for cystic fibrosis (CF) has been offered to pregnant women seeking chorionic villus sampling (CVS) for prenatal chromosomal abnormality investigation. The mutation panel has increased over the years to include 8 mutations and can detect 65% of abnormal CF genes in the Italian population. Testing was offered to a total of 2214 consecutive pregnant women; 45 of them declined screening (take up rate: 98%).

Prenatal diagnosis by chorionic villus sampling.

Chorionic villus sampling (CVS) retains its great advantage over mid-trimester amniocentesis by producing early results. Moreover, rapid analytical techniques reduce significantly the waiting time between sampling and diagnosis, while recombinant DNA technology and human gene mapping progress amplify enormously the spectrum of the indications. The recent inclusion in the prenatal diagnosis package of screening tests based on DNA analysis for the major genetic diseases (i.

International, collaborative experience of 1789 patients having multifetal pregnancy reduction: a plateauing of risks and outcomes.

Objective: To develop the most up-to-date, complete data base of multifetal pregnancy reduction (MFPR) from cases, and to provide the best counseling for couples with multifetal pregnancies.

Methods: From nine centers in five countries, 1789 completed MFPR cases were collected and outcomes evaluated. Pregnancy losses were defined as through 24 weeks and deliveries categorized in groups of 25-28, 29-32, 33-36, and 37 or more weeks.

First trimester fetal reduction: its role in the management of twin and higher order multiple pregnancies.

Multiple pregnancy may be the result of stimulated or non-stimulated, and of assisted or natural conception. As observed in the past decade, assisted conception technologies have significantly increased the prevalence of multiple pregnancy. The increase has been much more marked for triplets and higher order births.

Genetic analysis prior to selective fetal reduction in multiple pregnancy: technical aspects and clinical outcome.

Multiple pregnancies resulting from ovarian stimulation are at a higher risk of carrying at least one fetus affected by Mendelian or chromosomal anomalies, the incidence of which is directly related to the order of multiples. Genetic analysis before fetal reduction was offered to both high- and low-risk pregnant women carrying two or more fetuses after ovulation induction. Chorionic villus sampling (CVS) and fetal reduction were achieved by transabdominal needling.

First-trimester Down's syndrome screening using nuchal translucency: a prospective study in patients undergoing chorionic villus sampling.

The value of the measurement of nuchal translucency thickness for predicting fetal Down's syndrome and other aneuploidies was prospectively evaluated at 8-15 weeks of gestation in 1819 consecutive pregnancies scheduled for karyotyping by chorionic villus sampling. In 43 cases, a chromosomal unbalanced aberration was found. Two teams of ultrasonologists who examined patients attending either National Health Service (Series 1) or private practice clinics (Series 2) were involved in the study.

Serum PAPP-A and free beta-hCG are first-trimester screening markers for Down syndrome.

Serum measurements of pregnancy-associated plasma protein A (PAPP-A) and the free beta-human chorionic gonadotrophin (hCG) subunit were made in 13 women with Down syndrome (DS) pregnancies and six other women with fetal aneuploidy ascertained at chorionic villus sampling (CVS), as well as 89 women with contemporaneous normal control pregnancies. Median serum PAPP-A measurements (0.31 MOM, 95 per cent confidence interval (CI) 0.

Multiple pregnancy induction and selective fetal reduction in high genetic risk couples.

Couples at risk for an inherited disorder often have several pregnancy interruptions because of affected fetuses and difficulty in achieving their desired family. We evaluated the efficiency and acceptability of selective fetal reduction after chorionic villus sampling (CVS) of multiple pregnancy induced by ovarian stimulation and gamete intra-Fallopian transfer (GIFT). This approach has been offered to nine patients at risk of Mendelian diseases and one patient carrier of reciprocal translocation.

Low maternal serum levels of pregnancy associated plasma protein A (PAPP-A) in the first trimester in association with abnormal fetal karyotype.

Objective: To assess the relation between maternal serum pregnancy associated plasma protein A (PAPP-A) in the first trimester and the outcome of pregnancy by karyotype.

Design: A retrospective study of PAPP-A levels in blood samples collected prior to chorionic villus sampling.

Setting: Milan, Italy.

Genetic diagnosis by chorionic villus sampling before 8 gestational weeks: efficiency, reliability, and risks on 317 completed pregnancies.

Transabdominal chorionic villus sampling (TA-CVS) was attempted in 328 high-risk pregnancies at 6-7 weeks of gestation. Sampling was feasible in 97.7 per cent of cases; chorionic tissue specimens of more than 10 mg were obtained in 94.

First-trimester genetic diagnosis in multiple pregnancy: principles and potential pitfalls.

Both the principles of first-trimester genetic diagnosis in multiple pregnancy and the special considerations required to avoid potential diagnostic pitfalls are presented. The experience consisted of 65 cases of twins and one case of quadruplets. Dichorionic twins were recognized by sonography in 54 cases.