Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Chorionic Villi Sampling”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,171 records · Page 65Linked to original sources

A randomised controlled trial of biopsy forceps and cannula aspiration for transcervical chorionic villus sampling.

OBJECTIVE: This trial compared two instruments for transcervical chorionic villus sampling (CVS). DESIGN: Randomised controlled trial. SETTING: Regional university prenatal diagnosis and treatment centre. POPULATION: Two hundred women were randomised at 10(+0)-12(+6) weeks of gestation to transcervical CVS using cannula aspiration (CA) or biopsy forceps (BF). METHODS: Women undergoing indicated CVS signed informed consent. Randomisation after decision to perform transcervical CVS. MAIN OUTCOME MEASURES PRIMARY OUTCOME: the rise in maternal serum alpha-fetoprotein (alpha-FP). SECONDARY OUTCOMES: (i) placental trauma (fetomaternal haemorrhage [FMH]); (ii) laboratory, procedure, and cytogenetic results and pregnancy outcomes; (iii) patient and operator satisfaction; and (iv) economic analyses. Analyses were performed by intention to treat. RESULTS: The -FP rise did not differ between groups; there was no other evidence of placental trauma. BF were better tolerated by women, provided culturable tissue, after fewer instrument passes, with greater ease and in less time. BF were associated with cost savings. CONCLUSIONS: Unlike -FP, other markers of FMH were unaltered, questioning the reliability of alpha-FP as an indicator of FMH. Compared with CA, transcervical BF caused comparable placental trauma, appeared to be similarly effective and safe and were preferred by operators and patients.

Biopsy, Needle↗

Four-dimensional ultrasonographic guidance for invasive obstetric procedures.

OBJECTIVE: This pilot study evaluated the use of 4-dimensional (4D) real-time ultrasonographic needle guidance for amniocentesis, chorionic villus sampling (CVS), cordocentesis, and intrauterine transfusions. METHODS: Ninety-nine consecutive procedures were performed with 4D (real-time) multiplanar ultrasonographic imaging. Amniocentesis was done freehand in 3 orthogonal planes of view. Chorionic villus sampling, cordocentesis, and intrauterine transfusions were accomplished with a needle guide and 2 projected orthogonal planes. RESULTS: Needle tip visualization in the A, B, and C orthogonal planes during amniocentesis was noted in 93%, 63%, and 69% of cases, respectively. When a needle guide was used during CVS and cordocentesis, the needle tip was always seen in the 2 projected orthogonal planes, and no lateralization occurred. Four intrauterine transfusions were done with the 4D technique. The only procedural complication in any patient was bradycardia from vessel spasm during an intrauterine transfusion, requiring a cesarean delivery. There were no statistical differences (P > .05) between the numbers of needle insertions required in the 4D group compared with a historical control group in which 2-dimensional ultrasonographic needle guidance was used. CONCLUSIONS: In this feasibility study, a real-time 4D needle guidance technique was successfully used to perform amniocentesis, CVS, cordocentesis, and intrauterine transfusion. This appeared to contribute to the accuracy of needle placement by eliminating the lateralization phenomenon when a fixed needle guide attachment was used (for CVS and cordocentesis). Needle tip visualization was seen in each orthogonal plane in most freehand 4D amniocentesis cases. Future developments in 4D ultrasonographic technology may refine the utility of this technique for invasive obstetric procedures.

Amniocentesis↗

Perinatal outcome of chorionic villus sampling versus amniocentesis.

This study assesses the relative risks of first trimester transcervical chorionic villus sampling (CVS) versus midtrimester amniocentesis performed between April 1986 and March 1988. The most common indication for prenatal diagnosis was advanced maternal age. We discovered 5.1% chromosomal aberrations in CVS compared to 1.0% in amniocentesis. Bleeding was the most frequent early complication, and only 1 case had major hemorrhage with subsequent spontaneous abortion. The fetal loss rate (gestational age less than 28 weeks) was 4.5% in CVS versus 1.2% in amniocentesis, which was not significantly different from the background fetal loss rate reported in normal pregnancies after an 8-week gestational age. Three cases of fetal loss after CVS were probably procedure-related; 1 case had spontaneous abortion and 2 cases had chorioamnionitis. Therefore, we considered that the causal relationship between CVS and the infection was highly probable. The clinical pregnancy outcome indicated that there were no differences in overall perinatal mortality, Apgar score, body weight, body length, gestational age at delivery, intrauterine growth retardation, placenta weight and placental disorders between the CVS group and the amniocentesis group. The pregnancies did not reveal any specific effects of the prenatal diagnostic procedure, but a long-term pediatric follow-up is needed.

Abortion, Spontaneous↗

Technical aspects of transcervical chorionic villus sampling.

Following the 1990 FDA approval of the Trophocan catheter for use in transcervical chorionic villus sampling (CVS), an increasing number of US physicians have begun offering the procedure. To obtain privileges to perform CVS, some states such as California have enacted legislation requiring the performance of a certain number of CVS procedures in pregnancies in which the patient has already chosen first-trimester abortion. This practice is not universally feasible for legal, logistic, or financial reasons. We describe our approach to training in a busy reproductive genetics service. The physician initially trains by performing amniocentesis to optimize skills in ultrasound-directed needle guidance and placement. During this initial period, he or she also assists in performing transabdominal CVS procedures. The initial transcervical CVS cases should be performed in those situations requiring minimal catheter manipulation, or in those individuals undergoing CVS in the setting of spontaneous abortion. Cases of increasing difficulty should only be performed as skill and familiarity increase. For a physician already skilled and experienced in ultrasound-guided invasive procedures, sequential periods of observation at a busy center allows him or her to become familiar with the common pitfalls in performing transcervical CVS, and thus avoid them. Using this approach, we have performed over 5,000 CVS procedures and trained 6 reproductive genetics fellows in transcervical CVS.

Cervix Uteri↗

Detection of paternally inherited fetal point mutations for beta-thalassemia using size-fractionated cell-free DNA in maternal plasma.

CONTEXT: Currently, fetal point mutations cannot be reliably analyzed from circulatory fetal DNA in maternal plasma, due to the predominance of maternal DNA sequences. However, analysis of circulatory fetal DNA sequences in maternal plasma have been shown to selectively enrich for fetal DNA molecules on the basis of a smaller molecular size than maternal DNA. OBJECTIVE: To examine the prenatal analysis of 4 common beta-thalassemia point mutations: IVSI-1, IVSI-6, IVSI-110, and codon 39. DESIGN, SETTING, AND PATIENTS: A total of 32 maternal blood samples were collected at 10 to 12 weeks of gestation (mean, 10.7 weeks) between February 15, 2003, and February 25, 2004, in Bari, Italy, from women with risk for beta-thalassemia in their newborns immediately prior to chorionic villous sampling. Samples in which the father and mother did not carry the same mutation were examined. Circulatory DNA was size-fractionated by gel electrophoresis and polymerase chain reaction (PCR) amplified with a peptide-nucleic-acid clamp, which suppresses amplification of the normal maternal allele. Presence of the paternal mutant allele was detected by allele-specific real-time PCR. MAIN OUTCOME MEASURE: Detection of paternally inherited beta-globin gene point mutations. RESULTS: Presence or absence of the paternal mutant allele was correctly determined in 6 (86%) of 7 cases with the IVSI-1 mutation, 4 (100%) of 4 with the IVSI-6 mutation, 5 (100%) of 5 with the IVSI-110 mutation, and 13 (81%) of 16 with the codon 39 mutation. One false-positive test result was scored for the IVSI-1 mutation. Two cases with the codon 39 mutation were classified as uncertain and 1 case was excluded due to lack of a diagnostic test result at the time of analysis. These results yielded an overall sensitivity of 100% and specificity of 93.8%, with classified cases removed. CONCLUSION: Our recently described technique of the size-fractionation of circulatory DNA in maternal plasma may be potentially useful for the noninvasive prenatal determination of fetal point mutations.

Chorionic Villi Sampling↗

Striking facial dysmorphisms and restricted thymic development in a fetus with a 6-megabase deletion of chromosome 14q.

During routine ultrasound screening at 12 weeks 5 days of gestation, a nuchal translucency of 7 mm, an omphalocele, and fetal hydrops were found and prompted chorionic villus sampling at 13 weeks 2 days. Chromosome analysis showed an unbalanced karyotype with an abnormal chromosome 14. The mother was a carrier of a translocation karyotype 46,XX,t(13;14) (q34;q32.2). In the fetus this gave rise to a partial trisomy 13q and partial monosomy 14q (fetal karyotype: 46,XX,der[14]t[13;14][q34;q32.2]). By Array-CGH on DNA extracted from a postmortem skin culture, a duplication of approximately 1.7 Mbp of the distal part of chromosome 13q34 and a deletion of approximately 6.0 Mbp of the distal part of chromosome 14q32.2 was demonstrated. Postmortem findings after termination of pregnancy at 14 weeks 6 days included, among others, a severe hypoplasia of the median part of the maxilla, no recognizable nose, a broad median palatoschisis, nonlobulated lungs, a horseshoe kidney with multicystic dysplasia, and decreased development of cortical cellularity in the thymus. These clinical manifestations and autopsy findings of the fetus are compared with those of previously published cases and the possible involvement in this pathology of the YY1 and JAG2 transcription factors and the BCL11b and SIVA-1 regulators of thymic development is discussed.

Abnormalities, Multiple↗

Limb defects and chorionic villus sampling: results from an international registry, 1992-94.

BACKGROUND: Several reports of limb defects occurring among infants exposed to chorionic villus sampling (CVS) during pregnancy resulted in concern about the safety of this procedure for prenatal diagnosis. To avoid publication bias and evaluate the true risk of limb defects in a CVS cohort, the World Health Organization initiated international registration of post-CVS limb defects in 1992. METHODS: From May, 1992, to May, 1994, 77 infants or fetuses with limb defects from 138 996 pregnancies having CVS were reported to the WHO CVS Registry. These cases were analysed by standardised methods-ie, exclusion of syndromes, inherited disorders, and defects occurring in previable fetuses. The included limb deficiencies were studied by pattern analysis. FINDINGS: Defects of the upper limbs were reported in 64.6%, of the lower limbs in 12.5%, and of both upper and lower limbs in 20.8% of cases. These figures are in agreement with the distribution of limb defects in several large population-based studies. Transverse limb defects occurred in 40.8% and longitudinal defects in 59.2%, compared with 42.7% and 57.3% in an unexposed population. INTERPRETATION: The analysis of this cohort did not show any differences from the background population in the overall frequency or pattern distribution of limb deficiencies. There was also no correlation between gestational age at CVS and severity of defects. Therefore these results do not indicate any increased risk of limb defects after CVS.

Arm↗

Mosaicism in chorionic villus sampling.

Although chromosomal mosaicism is encountered frequently in CVS, it is most often restricted to the extraembryonic tissues. Counseling before CVS should include a discussion of the frequency and significance of placental mosaicism. Patients seeking information about the procedure need to be aware of the slight but not negligible possibility of the need for additional follow-up studies. Additional studies may involve additional risks with emotional and psychological sequelae. Ultimately, no prenatal procedure or combination of procedures can provide 100% accuracy in excluding mosaicism once the issue has been raised. When the mosaicism is felt to be confined to the placenta, counseling should probably address the potential increased risk for pregnancy complication, such as miscarriage and IUGR, with appropriate follow-up of the pregnancy, especially in the third trimester. Excluding the issue of mosaicism, the predictive value of cytogenetic diagnosis after CVS is equivalent to that of amniocentesis. In addition, CVS provides this information at an earlier time in the pregnancy than does amniocentesis. The majority of patients electing CVS (98% or more) will not have to deal with these complicated issues. It is hoped that an increasing cumulative experience with CVS mosaicism will help differentiate low- from high-risk situations. At the present time, however, there are insufficient and inconsistent data with which to accurately assess the risks associated with placental mosaicism. Most of the available literature concludes that additional, more focused studies, including long-term follow-up, are needed to help elucidate a better understanding of these issues.

Chorionic Villi Sampling↗

Prenatal testing in ICSI pregnancies: incidence of chromosomal anomalies in 1586 karyotypes and relation to sperm parameters.

BACKGROUND: Prenatal testing was offered in all pregnancies obtained after ICSI with ejaculated or non-ejaculated sperm as part of the evaluation of the safety of ICSI. METHODS: Between 1990 and 2001, a chorionic villus sampling (CVS) or amniocentesis was offered for multiple or singleton pregnancies respectively during a genetic counselling session for all couples applying for ICSI. ICSI was carried out using ejaculated, epididymal or testicular sperm. RESULTS: In total, 1586 ICSI fetuses obtained after fresh embryo transfer were tested by CVS (n = 698) or by amniocentesis (n = 888). Abnormal fetal karyotypes were found in 47 samples [3.0%; 95% confidence interval (CI) 2.2-3.9%]; 25 anomalies (1.6%; 95% CI 1.0-2.3%) were de novo. These were 10 sex chromosomal anomalies and 15 autosomal anomalies [either numerical (n = 8) or structural (n = 7)], and 22 inherited abnormalities (1.4%; 95% CI 0.9-2.1%) (21 balanced, one unbalanced). In 17/22 inherited cases the chromosomal structural defect was inherited from the father. A significantly higher percentage of 2.1% de-novo prenatal chromosomal anomalies was observed for sperm concentrations of <20x10(6) sperm per ml, as compared with 0.24% if the sperm concentration was vertical line 20x10(6) sperm per ml (Fisher's exact test, P = 0.006). No statistical difference in frequency of chromosomal anomalies was observed for lower threshold values of sperm concentration (<1x10(6), <5x10(6), <10x10(6) and <15x10(6)). A statistical difference was observed for motility criteria, but not morphology. Three chromosomal anomalies were found prenatally after use of epididymal or testicular sperm in a total of 94 samples; two (of 83 tested) were from patients with obstructive and one (of nine tested) was from a patient with non-obstructive azoospermia. CONCLUSIONS: A significantly higher rate of de-novo chromosomal anomalies (1.6 versus 0.5% in amniocentesis for a mean maternal age of 33.5 years; P < 0.007) was observed in ICSI offspring, relating mainly to a higher number of sex chromosomal anomalies and partly to a higher number of autosomal structural anomalies. This finding was related to sperm concentration and motility. The significantly higher rate of observed inherited anomalies (1.4 versus 0.3-0.4% in prenatal tests in the general population; P < 0.001) was related to a higher rate of constitutional chromosomal anomalies, mainly in the fathers. The hypothesis of a higher risk of post-zygotic events as a consequence of the ICSI procedure leading to a higher proportion of chromosomal mosaicism was not confirmed in this study. Couples should be informed of the risks of an abnormal result related to sperm quality, and of the risk linked to a prenatal procedure as well as about the relatively benign character of some chromosomal anomalies such as de-novo structural anomalies or sex chromosomal anomalies in order to be able to make a choice for prenatal testing, or not.

Adult↗

Prenatal diagnosis of the fragile X syndrome: possible end of the experimental phase for amniotic fluid.

We have had experience with 260 prenatal diagnosis cases for the fragile X syndrome [fra(X)]; amniotic fluid was received in 230. There was a documented family history of fra(X) in 148 amniotic fluid cases. Our sample includes 91 males. Eleven were correctly identified as fra(X)-positive and 2 were false-negative. Eight of 57 females were fra(X) positive and one was a false-negative. CVS were received in 21 cases with a family history of fra(X), and there were 2 positive results in females and 3 false-negative results in males which were ultimately detected by means of molecular analysis or a subsequent amniotic fluid specimen. RFLPs were utilized in 29 cases (amniotic fluid and CVS); RFLPs identified 2 false-negative cytogenetic results in CVS. Two male fetuses were found to have a high probability of being affected by means of RFLPs, but on the basis of prenatal and postnatal negative fra(X) cytogenetic results and subsequent normal growth and development, they are either unaffected transmitting males or are double recombinants. Three female fetuses were also found to be cytogenetically negative in CVS but had a 90%, 93%, and 99% probability of being affected by RFLPs. On the basis of the data, it can be concluded: 1. Amniotic fluid experience is adequate to eliminate the "experimental" designation providing the limitations are understood and an experienced laboratory is involved. 2. Chorionic villus cells for cytogenetic analysis should still be considered experimental. 3. Negative results with CVS should be confirmed by molecular methods and/or by cytogenetic analysis of another tissue. 4. Multiple approaches can maximize reliability of fra(X) prenatal diagnosis.

Amniocentesis↗

Obstetric outcome after prenatal diagnosis in pregnancies obtained after intracytoplasmic sperm injection.

In this study we compared the pregnancy outcome of 576 pregnancies after prenatal diagnosis with that of 540 pregnancies without prenatal diagnosis in our microinjection programme. Amniocentesis was suggested for singleton pregnancies (n = 465) and chorionic villus sampling (CVS) was proposed for twin pregnancies (n = 111 pregnancies, 222 fetuses). A total of 365 patients with singleton pregnancies and 175 patients with twin pregnancies who did not undergo prenatal diagnosis were selected as controls. Compared with the controls, the odds ratios in the amniocentesis group for preterm delivery, low birthweight, very low birthweight and fetal loss were 0.97 [95% confidence interval (CI): 0.60-1.57], 1.27 (95% CI: 0.78-2.06), 1.57 (95% CI: 0.53-4.66) and 0.86 (95% CI: 0.32-2.37) respectively. Compared with the controls, the odds ratios in the CVS group for preterm delivery, low birthweight, very low birthweight and fetal loss were 0.89 (95% CI: 0.61-1.30), 1.03 (95% CI: 0.74-1.45), 0.79 (95% CI: 0.41-1.53) and 0.47 (95% CI: 0.17-1.30) respectively. We concluded that, in this series of intracytoplasmic sperm injection (ICSI) pregnancies, prenatal testing did not increase the preterm-delivery, the low-birthweight, or the very low-birthweight rates as compared with those of the controls. In the prenatal diagnosis group, the fetal loss rate was comparable to that of the control group. Larger prospective controlled studies are needed in order to inform patients reliably about the risks and the advantages of prenatal testing in ICSI pregnancies.

Adult↗

Transcervical chorionic villus sampling beyond 12 weeks of gestation.

The aim of this study was to evaluate the feasibility of transcervical chorionic villus sampling (CVS) after 12 completed weeks of pregnancy. The transcervical route for CVS, using thin biopsy forceps, was accomplished in 335 procedures in the study group, between 12 + 1 and 15 + 0 weeks. Cases were subdivided into two subgroups, the late (13 + 0 to 15 + 0 weeks) and intermediate (12 + 1 and 12 + 6 weeks) subgroups, and the results were compared with a previous series of 1202 early (8 + 0-12 + 0 weeks) transcervical CVS. A successful diagnosis was made in 97.3% of the cases. No differences were found in diagnostic success between the study subgroups, in comparison to the early transcervical CVS series. However, success rates in the study group increased from 90% in the first 60 procedures to 98.9% in the remaining cases (p < 0.001). Amniocentesis was eventually performed in nine cases (2.7%). All cases were rescanned 2 weeks after the procedure, and fetal demise was detected in five cases (1.5%). The spontaneous fetal loss rate up to 28 weeks was 3.1% (2.7% for intermediate and 4.0% for late subgroups). No cases of transverse limb reduction defects were observed. The results of our study suggest that the transcervical route for CVS beyond the 12th week of pregnancy has a satisfactory diagnostic success rate, and an acceptable pregnancy loss rate.

Adult↗

Prenatal diagnosis for congenital adrenal hyperplasia in 532 pregnancies.

Congenital adrenal hyperplasia (CAH) refers to a family of monogenic inherited disorders of adrenal steroidogenesis most often caused by enzyme 21-hydroxylase deficiency (21-OHD). In the classic forms of CAH (simple virilizing and salt wasting), androgen excess causes external genital ambiguity in newborn females and progressive postnatal virilization in males and females. Prenatal treatment of CAH with dexamethasone has been successfully used for over a decade. This article serves as an update on 532 pregnancies prenatally diagnosed using amniocentesis or chorionic villus sampling between 1978 and 2001 at New York Presbyterian Hospital-Weill Medical College of Cornell University. Of the 532 pregnancies, 281 were prenatally treated for CAH due to the risk of 21-hydroxylase deficiency. Follow-up telephone interviews with mothers, genetic counselors, endocrinologists, pediatricians, and obstetricians were performed in all cases. Of the pregnancies evaluated, 116 babies were affected with classic 21-OHD. Of these, 61 were female, 49 of whom were treated prenatally with dexamethasone. Dexamethasone administered at or before 9 wk gestation (in proper doses) was effective in reducing virilization. There were no statistical differences in the symptoms during pregnancy between mothers treated with dexamethasone and those not treated with dexamethasone, except for weight gain, edema, and striae, which were greater in the treated group. No significant or enduring side-effects were noted in the fetuses, indicating that dexamethasone treatment is safe. Prenatally treated newborns did not differ in weight from untreated, unaffected newborns. Based on our experience, prenatal diagnosis and proper prenatal treatment of 21-OHD are effective in significantly reducing or eliminating virilization in the newborn female. This spares the affected female the consequences of genital ambiguity, genital surgery, and possible sex misassignment.

Adrenal Hyperplasia, Congenital↗

Chorionic villus sampling and amniocentesis: recommendations for prenatal counseling. Centers for Disease Control and Prevention.

Chorionic villus sampling (CVS) and amniocentesis are prenatal diagnostic procedures that are performed to detect fetal abnormalities. In 1991, concerns about the relative safety of these procedures arose after reports were published that described a possible association between CVS and birth defects in infants. Subsequent studies support the hypothesis that CVS can cause transverse limb deficiencies. Following CVS, rates of these defects, estimated to be 0.03%-0.10% (1/3,000-1/1,000), generally have been increased over background rates. Rates and severity of limb deficiencies are associated with the timing of CVS; most of the birth defects reported after procedures that were performed at > or = 70 days' gestation were limited to the fingers or toes. The risk for either digital or limb deficiency after CVS is only one of several important factors that must be considered in making complex and personal decisions about prenatal testing. For example, CVS is generally done earlier in pregnancy than amniocentesis and is particularly advantageous for detecting certain genetic conditions. Another important factor is the risk for miscarriage, which has been attributed to 0.5%-1.0% of CVS procedures and 0.25%-0.50% of amniocentesis procedures. Prospective parents considering the use of either CVS or amniocentesis should be counseled about the benefits and risks of these procedures. The counselor should also discuss both the mother's and father's risk(s) for transmitting genetic abnormalities to the fetus.

Amniocentesis↗

Prospective audit of a one-centre combined nuchal translucency and triple test programme for the detection of trisomy 21.

OBJECTIVES: To determine detection and false-positive rates for trisomy 21 using two-stage combined nuchal translucency (NT) and triple testing, whilst disclosing abnormal nuchal measurements at the scan. METHODS: A prospective audit in a UK women's hospital, of 3188 women with singleton pregnancies, requesting screening for trisomy 21. Median age was 37 years (range 19-46). Women were offered NT screening at 11 to 14 weeks. Those with NT > or =3 mm were offered chorionic villus sampling. Those declining CVS, and those with NT <3 mm, were offered early triple tests. Women with a term combined risk of trisomy 21 > or = 1:250, based on age, NT, and triple test results were offered amniocentesis. RESULTS: Using a 3-mm NT 'cut-off' identified 16/25 cases of trisomy 21 (64%; 95% CI 38.8, 78.9). Of 2725 women who had a combined nuchal plus triple test assessment, 79 (2.6%) had a > or = 1:250 term risk of trisomy 21. Forty (1.3%) had amniocentesis identifying 6/9 remaining cases (67%:95% CI:27.9, 92.5). Overall, the detection rate was 88% (95% CI:68.8, 97.5) for a 4.8% FPR. For the screened population, to achieve an 88% detection rate using the triple test alone, the predicted FPR would be 20%. Conversely, for an FPR of 4.8% using the triple test alone, the detection rate would be only 60%. CONCLUSION: In a high-risk group, the combination of NT with triple test offers detection of trisomy 21 at least equivalent to either test, while allowing disclosure of an abnormal NT at the scan and reducing the FPR. Importantly, the FPR is less than 5%, considerably lower than expected for triple test alone for this population.

Adult↗

Amniocentesis and chorionic villus sampling.

Amniocentesis and chorionic villus sampling (CVS) remain the most commonly used invasive prenatal diagnostic procedures. Recent reports on early amniocentesis demonstrate its application to the prenatal detection of certain biochemical disorders. However, its role in the evaluation of open fetal defects of the neural tube or ventral wall is still under investigation. The fact that many reports concerning early amniocentesis include a majority of patients beyond 11 to 12 weeks' gestation, thus placing the procedure outside the first trimester, make comparisons with CVS (usually performed between 9 and 11 weeks) problematic. The role of midtrimester amniocentesis in evaluating elevations of maternal serum alpha-fetoprotein, following a normal ultrasonographic examination performed specifically to detect fetal anomalies, is under scrutiny. It appears that risk adjustment may be appropriate following a normal scan, and prior to invasive procedures, but each center's recommendation to a given patient will depend on the expertise of the individual sonographer, as well as the quality of examination. CVS has gained acceptance as a safe first-trimester means of prenatal diagnosis, with increasing applications in the later stages of pregnancy. Chromosomal mosaicism detected by CVS may represent a phenomenon inherent to placental tissue; questions remain regarding mosaicism as a potential marker for increased pregnancy loss. Comparisons between the transcervical and transabdominal routes are reviewed, with equivalent results regarding safety and efficacy. Recent evaluations of fetomaternal transfusion following CVS are also described.

Amniocentesis↗

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. The same type of ultrasound machine and standardized approach were used in both study groups. In those cases in which the maximum subcutaneous thickness of the translucency was 3 mm or greater, the incidence of chromosomal aberration was 18.6% compared to 1.7% in the cases in which this was below 3 mm. The sensitivity, specificity and relative risk for all aneuploidies were 30%, 96% and 10.83, respectively, and no difference was found between trisomy 21 and other types of aneuploidy. The sensitivity and specificity and relative risk were significantly higher at 9-10 weeks than between 11 and 15 weeks. The results were concordant in the two series; however, the overall values for sensitivity (20% vs. 39%), specificity (94% vs. 98%) and relative risk (4.13 vs. 24.20) were clearly higher in the group of private patients. The results obtained confirm the potential application of the measurement of nuchal translucency thickness for fetal aneuploidy screening before the end of the first trimester and suggest that a multiplicity of individual, structural and organizational factors may interact and play a crucial role in determining the actual efficiency of ultrasound screening programs.

Adult↗

Social and geographical inequalities in prenatal care in Italy.

The purpose of this study was to find out possible differences in prenatal diagnosis (PD) by amniocentesis or chorionic villus sampling and ultrasound examination before 16 weeks' gestation (early ultrasound examination, EUE), according to area of residence and level of education of the mothers. Data come from a multicentre study in Italy involving 43 maternity hospitals (Mercurio project) and were collected through structured interviews a few days after delivery. Study subjects were 1541 mothers of single non-malformed infants born between April 1992 and March 1994. Overall, the incidence of PD and EUE was 5.8 and 80 per cent, respectively. After adjustment for maternal age and other possible confounders, the odds ratios for PD were 2.19 (95 per cent confidence interval (CI) = 1.26-3.81) when women residing in the northern regions were compared with those residing in the southern regions, and 2.06 (95 per cent CI = 1.12-3.79) and 4.08 (95 per cent CI = 1.97-8.42) when women with medium and high levels of education were compared with those with low level. For EUE, the odds ratios were 1.77 (95 per cent CI = 1.32-2.36) and 2.88 (95 per cent CI = 1.56-5.29) when comparing women with medium and high levels of education with those with low level. No relationship was found between area of residence and EUE. These geographical and social inequalities in prenatal care in Italy should be taken into account for the organization, delivery, and evaluation of pregnancy services in the coming years.

Adult↗