Fibrinopeptide a increases after Chorionic villus sampling

Fibrinopeptide levels were measured in 20 women during transcervical chorionic villus sampling (CVS). Fibrinopeptide A, a sensitive indicator of fibrinogen cleavage by thrombin, significantly increased in five subjects, whereas there was no change in Bβ peptide, an indicator of fibrinolysis. The data suggest that modest fibrin formation, uncompensated by fibrinolysis, may be induced in some women by CVS.     

Transabdominal chorionic villus sampling in the second trimester of pregnancy: Feto-maternal transfusions in relation to pregnancy outcome

Volumes of feto-maternal transfusions (FMTs) in transabdominal chorionic villus sampling (TACVS) in the second trimester of pregnancy were calculated from the difference between maternal alpha-fetoprotein (AFP) concentrations before and 1 h after TACVS. In 50 pregnancies, there existed no correlation between FMT volume and the amount of villi collected or the number of TACVS attempts. The expected risk of fetal exsanguination due to very voluminous FMT could not be substantiated. In one case, immunization could have been the cause of hydrops fetalis, although only a volume of 0.15 ml could be calculated.     

Fetal exsanguination following intrauterine angiographic assessment and selective termination of a hydrocephalic,monozygotic co-twin

Selective termination by intracardiac potassium chloride injection was performed in twins discordant for hydrocephaly at 20 weeks' gestation. Because of the potential for vascular anastomoses to exist between the twins, fetal angiography was performed prior to the selective termination procedure. Determination of vascular connections between the fetuses was hindered by fetal bradycardia following intracardiac administration of contrast material. Selective termination was performed without difficulty using intracardiac potassium chloride (KCl) to produce asystole in the twin with hydrocephaly. The unaffected fetus appeared active and had a normal heart rate during and immediately after the procedure. However, both twins were found to have died the following day. Pathologic examination documented several vascular anastomoses between the monochorionic, diamniotic fetuses. A likely cause of death was exsanguination of the normal twin into the abnormal one. This case illustrates the difficulties encountered in selective termination of monozygotic twins and, to our knowledge, represents the first reported use of intrauterine fetal angiography.     

Risk evaluation in chorionic villus sampling

The occasion of the 18th symposium of the European Society of Human Genetics, 20 May to 2 June, provided an opportunity for the WHO to sponsor a small meeting on the progress of risk evaluation in three large programmes of chorionic villus sampling (CVS). Their pooled information showed a rate of fetal loss of 3·4 per cent in the first 300 cases in each programme, falling to 1·7 per cent in the following 400 cases.     

Evaluation of transcervical chorionic villus sampling with a completed follow-up of 1550 consecutive pregnancies

Data from 1550 consecutive pregnancies after first-trimester prenatal diagnosis by transcervical chorionic villus sampling (TC-CVS) are presented. The sampling efficacy was 97.8 per cent; the mean amount of collected villus tissue was 23 mg (range 5–100 mg). There were 97 affected fetuses, mainly (73.2 per cent) with a chromosomal abnormality or a male karyotype in carriers of X-linked disease. Pregnancy termination in these and four other women for social reasons resulted in 1449 continuing pregnancies. In these pregnancies, the fetal loss rate up to 28 weeks of gestation was 5.1 per cent with the highest loss rate (3.9 per cent) before 16 weeks. When relating this fetal loss rate to maternal age, this was 6.1 per cent in the advanced maternal age group (⩾36 years) against 3.1 per cent in the younger age group. In 1376 pregnancies continuing beyond 28 weeks, the perinatal mortality rate was 1.1 per cent; the percentage of non-genetic congenital anomalies was 0.9 per cent. The reproductive pattern of women at high genetic risk after CVS followed by pregnancy termination was evaluated. Within 12 months after the first CVS followed by pregnancy termination, 70 percent of women again requested CVS in a subsequent pregnancy.     

Clinical and pathological factors in spontaneous abortion following chorionic villus sampling

Twenty-nine cases of spontaneous abortion following first-trimester chorionic villus sampling (CVS) were reviewed out of a series of 722 patients. Of the 29 cases, there were only four abnormal CVS results. Pathological examination was performed in 79 per cent of cases, and this did not identify any characteristic pathological feature associated with spontaneous abortion after CVS. There was no obvious difference in the pathological features following the transabdominal (TA) or the transcervical (TC) methods. The majority of miscarriages occurred within 4 weeks of the procedure, but 38 per cent of cases aborted between 7 and 14 weeks after CVS. The TC method was used in 22 patients; the TA in 6; and both methods in 1 patient. The TA method was associated with a significantly lower fetal loss rate than the TC method (TA 2 per cent, TC 9 per cent, p < 0.001).     

Randomized trial comparing first-trimester transcervical chorionic villus sampling and second-trimester amniocentesis

A total of 800 patients were randomized at the 9th to 11th week of pregnancy either for transcervical chorionic villus sampling (CVS) on the day of trial entry or for amniocentesis (AC) at the 16th week. The indication for fetal karyotyping was maternal age in 94 per cent of the cases; the mean maternal age was 39.2 years. An adequate sample was obtained in 98.3 per cent of the cases in the CVS group and in all cases in the AC group. Retesting was indicated in 3.3 per cent of the CVS cases. An abnormal karyotype was found in 6.1 per cent of the CV samples and in 4.5 per cent of the amniotic fluid samples. There was one false-positive chromosome result in both groups. Twelve (3.1 per cent) miscarriages occurred by the 22nd week of pregnancy in the CVS group in pregnancies intended to continue. No difference was seen between the groups for total fetal loss rates. The number of surviving infants in the CVS group was 92.2 per cent and in the AC group 91.7 per cent (rate difference 0.5 per cent (95 per cent confidence interval − 3.3 to 4.3)). In our study, both the diagnostic accuracy and the risk of fetal loss were equal in the CVS and AC groups.     

Transabdominal chorionic villus sampling in the second and third trimesters of pregnancy: Chromosome quality,reporting time,and feto-maternal bleeding

Transabdominal chorionic villus sampling (TA-CVS) was performed in 210 pregnancies from 13 to 38 weeks using a double-needle technique. The sampling success was comparable to first-trimester TA-CVS and the diagnostic success rate was 98.2 per cent for the short-term technique and 99.3 per cent for cultured villi. Two fetuses could not be karyotyped. We found the chromosome quality to be similar to that in the first trimester, comparing the number of G-bands and other chromosome attributes. There were no unintended losses in a group (n = 142) with no sonographic abnormality, except for one death in utero at 38 weeks, 20 weeks after sampling. Chromosomal aberrations were seen in 19 per cent of cases with abnormal sonograms (n = 58). One case of a discordant karyotype was found (false-negative prediction of Down's syndrome by the short-term preparation). There were no cases of fetal demise due to feto-maternal bleeding. It is suggested that double-needle TA-CVS in advanced pregnancies combines the advantages of rapid karyotyping of chromosomes of good quality and low risk for the fetus, and seems to be easier to practise and is probably safer than cordocentesis.     

Chorionic villus sampling and acceptance rate of prenatal diagnosis

In this paper, we compared the acceptance rate of fetal diagnosis for β-thalassemia in three group of couples of Sardinian descent; the first counselled before DNA analysis was available, the second presenting after DNA analysis was introduced but too late for chorionic villus sampling and thus monitored by amniocyte DNA analysis and the third presenting within the first trimester after DNA analysis was introduced and thus in time for trophoblast DNA analysis. A higher proportion of couples from the latter group opted for fetal testing as compared to the 1st and 2nd group. These results indicate that in this population, introduction of 1st trimester diagnosis made prenatal testing acceptable to practically all counselled couples at risk.     

Mosaicism and accuracy of prenatal cytogenetic diagnoses after chorionic villus sampling and placental biopsies

Discrepant chromosome findings in placenta and fetus (false negative and false positive) after chorionic villus sampling (CVS) are mainly due to confined mosaicism. Non-mosaic normal or abnormal chromosome counts after direct preparation and culture nearly always correctly reflect the fetal chromosome constitution. False-negative results have almost exclusively been restricted to cytotrophoblast cells not representing a fetal chromosome abnormality. Diagnosis of placental mosaicism definitely requires an adequate follow-up by amniocentesis, fetal blood sampling, or sonography before a pregnancy is terminated. When direct preparations and cultured cells are used for cytogenetic diagnoses and placental mosaicism is not taken as proof for a chromosomal abnormality in the fetus, CVS is an accurate diagnostic tool.     

Chorionic villus sampling for fetal karyotyping in missed abortions

Chorionic villus sampling (CVS) was performed in 12 pregnant women (9–25 gestational weeks) with ultrasonographic evidence of missed abortion. An ultrasonographically guided transabdominal (eight cases) or transcervical (four cases) approach was used. Fetal karyo-typing was successful in all cases; in five, chromosomal aberrations were found and in seven, chromosome analyses revealed normal karyotypes. Tissue culture for fetal karyotyping was successful in only 72.5 per cent of 40 live pregnancies which were electively interrupted because of abnormal ultrasonographic findings or an abnormal fetal karyotype, and in 57 per cent of seven missed abortions. CVS is suggested as a feasible and effective method for fetal karyotyping in missed abortions and it seems to be superior to post-abortion tissue culture.     

Early prenatal direct gene diagnosis of cystic fibrosis in a twin pregnancy and subsequent selective termination

We present a case of prenatal diagnosis of cystic fibrosis (CF) in one twin at 11–12 weeks of gestation. The parents had previously had two children, one of whom is alive and healthy and one who died of CF at the age of 2½ months. The parents were both known to be carriers of the ΔF508 mutation. Chorionic villus sampling (CVS) was performed and direct gene analysis showed that one fetus was homozygous for the ΔF508 mutation, while the other fetus did not have the mutation at all. Both fetuses had normal karyotypes. Selective termination was subsequently performed. The pregnancy continued without complications except for mild pre-eclampsia at term. The woman had a Caesarean section. The genetic diagnosis was confirmed after birth.     

Transabdominal villus sampling in early second trimester: A safe sampling method for women of advanced age

Transabdominal chorionic villus sampling (TA-CVS) was performed in 707 viable singleton pregnancies to exclude chromosomal abnormalities. Maternal age ranged between 36 and 49 years (mean 37·9 years); gestational age varied between 10·2 and 18·3 weeks (mean 13·3 weeks). In 639 women (90·4 per cent), a sufficient amount of chorionic tissue (⩾ 10 mg) was obtained after one needle insertion; in 66 women (9·3 per cent) two insertions were needed. An abnormal chromosome pattern was established in 19 cases (2·9 per cent). Vaginal bleeding or spotting within 28 days after TA-CVS occurred in 11 cases (1·5 per cent). The completed follow-up of 678 chromosomally normal pregnancies showed an overall fetal loss rate of 2·6 per cent before 28 weeks. The overall perinatal mortality was 0·9 per cent. When relating fetal loss to gestational age at TA-CVS, this was 6·6 per cent in women sampled before 12 weeks against only 1·8 per cent after 12 weeks. At the same time, the percentage of fetal loss occurring within 2 weeks following the procedure was 75 and 30 per cent, respectively. It is suggested that these data reflect the decline in spontaneous abortion rate during this particular period of pregnancy. It is concluded that TA-CVS is an effective procedure which, when performed after the natural decrease of fetal loss, appears to be a safe option for women of advanced maternal age.     

Transabdominal chorionic villus sampling. Clinical experience of 1159 cases

The efficacy and risks of transabdominal free-hand ultrasound-guided fine needle aspiration technique were evaluated in 1159 pregnancies submitted to chorionic villus sampling (CVS) in the first trimester and early in the second trimester. An adequate amount of chorionic tissue was obtained by two needle insertions in 99·7 per cent of cases, and a second tapping was needed in 3·5 per cent of cases. A local peritoneal reaction was the only early complication clearly related to the procedure, and it occurred in 0·3 per pent of cases without any adverse effect on the maternal and fetal outcome. The correct abortion rate in 716 consecutive concluded pregnancies was 2·4 per cent, while the rate of late obstetrical complications and perinatal mortality and morbidity compares favourably with the rates in the general population. Because of its simplicity and practicability, transabdominal aspiration is the procedure of choice and is especially recommended fonintensive CVS routine conditions.     

Congenital malformations subsequent to chorionic villus sampling: Outcome analysis of 1048 consecutive procedures

We wished to identify the types and frequencies of malformations among continuing pregnancies exposed to chorionic villus sampling (CVS) and to determine whether selected procedure-related variables differ between the normal and anomalous cohorts. CVS was performed in 1048 patients between May 1988 and January 1992. Prospective assessment of perinatal outcome was ascertained by (1) physician—patient phone contact within 1 week of sampling, (2) ultrasound evaluation of the fetal anatomy at mid-gestation, (3) a detailed post-partum questionnaire completed by the referring obstetrician, and (4) a telephone interview with each patient after the expected date of confinement. Twenty-seven major malformations were documented among 938 pregnancies (live born, n=934; electively terminated, n=4), and included cardiac malformations (5), hypospadias (5), craniosynostosis (2), pyloric stenosis (2), inguinal hernia (2), polydactyly (2), syndactyly, distal extremely hemimelia, anencephaly, hydrocephalus, cleft lip and palate, omphalocele, diaphragmatic hernia, thanatophoric dysplasia, and unilateral cataract. Normal and anomalous cohorts were similar with respect to sampling method (transabdominal/transcervical ratio), mean gestational age at CVS, single-pass success rate, and mean total sample weight. No relationship between any procedure-related variable and the risk of malformation was observed.     

Expression of fragile-x in a female fetus diagnosed after chorionic villus sampling

Study of different tissues of an aborted female fetus showed similar levels of fragile-X expression (6.3–9.2 per cent) and of early replication of the FRAXA-positive cells (50–66 per cent) in fetal tissues. Different culture media did not significantly affect either investigation. It is suggested that the distribution of X-inactivation in FRAXA-positive chorionic villus cells of a female fetus might indicate her future phenotype.     

Chorionic villus sampling utilization following reports of a possible association with fetal limb defects

Prenatal diagnosis choices were reviewed in 473 women who presented for genetic counselling prior to 11 weeks' gestation for the indication of advanced maternal age. Group A consisted of 336 patients who were unaware of a possible association between chorionic villus sampling (CVS) and limb defects. Group B consisted of 137 patients who were provided this information. Fifty-one per cent of patients in group A and 45 per cent of patients in group B chose CVS. This difference was not significant by χ² analysis (P = 0·7). Patterns of prenatal diagnosis procedure utilization from 1987 to 1992 revealed a significant reduction in CVS utilization accompanied by a corresponding increase in amniocentesis after the association between CVS and limb defects was publicized. Referrals for CVS counselling also significantly declined. However, acceptance rates did not change for those patients who received genetic counselling. First-trimester genetic counselling, including a discussion regarding a possible association between CVS and limb defects, helps patients make informed decisions concerning prenatal diagnosis options, and, in our population, resulted in no change in CVS acceptance rates.     

First trimester diagnosis of RhO (D) with an immunofluorescence technique after chorionic villus sampling

Double indirect immunofluorescence technique (DIIF) was applied to fetal erythrocytes from vascularized chorionic villi, obtained by chorionic villus sampling (CVS) in the first trimester of pregnancy, to determine the presence of Rhesus antigen Rh (D).