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Biomedical subjects

F J Los

Publications and source records attributed to F J Los.

At least 37 records · Page 2Linked to original sources
PubMed1999

Amniocentesis or chorionic villus sampling in multiple gestations? Experience with 500 cases.

500 women with multiple pregnancies underwent amniocentesis or chorionic villus (CV) sampling at our department between January 1988 and July 1997. The aim of this retrospective study was to evaluate the laboratory aspects and the consequences of discordant results in these pregnancies in relation to the method of sampling. Uncertain results in one or both samples, requiring further investigation were more frequent in CV samples (eight times in 163 paired samples, 5 per cent) than in amniotic fluid (AF) samples (once in 298 paired samples, 0.3 per cent). Sampling one fetus twice (erroneous sampling) was seen only once among 163 pregnancies with two CV samples in our study. Cross contamination due to mixed sampling was discovered in two of seven pregnancies that underwent DNA diagnosis in CV and might be a rather regular occuring phenomenon. In none of the 500 pregnancies mixed sampling caused diagnostic dilemmas. A third sampling problem, maternal cell contamination caused a diagnostic problem once among the AF samples. Selective fetal reduction appeared safer after CV sampling than after amniocentesis. Subsequently, CV sampling instead of amniocentesis has become the method of choice for prenatal diagnosis in multiple pregnancies in our department.

Amniocentesis↗
PubMed1998

Abnormal karyotypes in semi-direct chorionic villus preparations of women with different cytogenetic risks.

Among 3499 cytogenetically investigated semi-direct chorionic villus samples, 219 (6.3 per cent) abnormal karyotypes were encountered. The karyotypes were considered certainly abnormal (generalized abnormal with high probability) in 109 cases (3.1 per cent), and in 110 cases (3.1 per cent) uncertainly abnormal (potentially confined to the placenta), requiring further investigation. Of these 110 uncertain abnormalities, the cytogenetic result turned out to be finally abnormal representing generalized abnormality in 36 cases (32.7 per cent), finally normal representing confined placental mosaicism (CPM) in 69 cases (62.7 per cent), and remained undetermined in 5 instances (4.5 per cent). The rate of the numbers of certainly abnormal and all (certainly + uncertainly) abnormal results, the certainty rate, and that of generalized abnormalities and all abnormalities (generalized abnormalities + CPM cases), the predictive value, are strongly correlated with the cytogenetic risk. Therefore, we advise chorionic villus sampling for cytogenetic investigation only in women with a cytogenetic risk equal to or exceeding that of a 40-year-old pregnant woman. Because of the high rate of prenatal follow-up investigations after the finding of uncertain results in semi-direct villi, semi-direct and cultured villi should be karyotyped simultaneously.

Adult↗
PubMed1998

Prospective prenatal investigations on potential uniparental disomy in cases of confined placental trisomy.

In most reported cases of uniparental disomy (UPD) associated with confined placental mosaicism (CPM), a high level of mosaicism or a full trisomy was found in chorionic villi. At the time that we started our investigations, it was not quite clear whether fetal UPD also existed in the more frequently occurring low levels of mosaicism. During a 4-year period, a follow-up amniocentesis was performed in all cases of mosaic or non-mosaic trisomy detected in chorionic villus (CV) semi-direct preparations and suspected to be confined to the placenta. We performed fluorescent in situ hybridization (FISH) on uncultured amniotic fluid cells to differentiate between generalized mosaicism and CPM. We found 29 cases of CPM and we determined the incidence of UPD in 23 of these cases. Normal biparental chromosome contributions were found in 22 cases. In one case, we detected a maternal heterodisomy for chromosome 16. UPD appeared to be a rare phenomenon in the cases of CPM (type I and/or type III) that we encountered in 3958 consecutively investigated CV samples, and is not the cause of the pregnancy complications found in seven out of 23 cases with CPM.

Amniocentesis↗
PubMed1998

Uniparental disomy with and without confined placental mosaicism: a model for trisomic zygote rescue.

In the population of children born after prenatal cytogenetic investigation in chorionic villi at our department from 1992 to 1995 (N = 3940), three are known to us with uniparental disomy. One case of maternal heterodisomy 16 was prenatally discovered because of trisomy 16 in direct chorionic villi with subsequently normal amniotic fluid cells. The other two had normal karyotypes in chorionic villi. Maternal heterodisomy 15 was postnatally detected in one of them because of Prader-Willi syndrome. Maternal hetero/isodisomy 16 was accidentally encountered in the other case in the course of prenatal DNA analysis of the tuberous sclerosis complex 2 region at 16p13.3. A model is presented for the understanding of the various combinations of karyotypes in direct chorionic villi, cultured chorionic villi and the fetus in the case of successful and unsuccessful trisomic zygote rescue.

Adult↗
PubMed1997

Prenatal diagnosis of trisomy 9: cytogenetic, fish, and DNA studies.

A cytogenetic survey and follow-up studies were performed in eight cases of full, mosaic, and pseudomosaic trisomy 9 prenatally diagnosed among 36,213 prenatal samples in our department between August 1970 and July 1996. Besides conventional chromosome analysis, interphase fluorescent in situ hybridization (FISH) was employed. FISH turned out to be a rapid and accurate method for verification of trisomy cell lines and could provide additional information to the prenatal cytogenetic results. FISH also enables the study of uncultured specimens of amniotic fluid, not accessible for traditional cytogenetic analysis. In three cases, retrospective DNA analysis showed the supernumerary chromosome 9 to be of maternal origin. The disomic cell lines in both mosaic trisomy 9 cases showed maternal uniparental disomy.

Alleles↗
PubMed1997

Determination of the parent of origin in nine cases of prenatally detected chromosome aberrations found after intracytoplasmic sperm injection.

Prenatal cytogenetic analysis of 71 fetuses conceived by intracytoplasmic sperm injection (ICSI) resulted in the detection of nine (12.7%) chromosome aberrations including two cases of 47,XXY, four cases involving a 45,X cell line and three autosomal trisomies. Molecular analysis of the parental origin of the deleted or supernumerary chromosome was performed by using polymorphic microsatellite markers. Six cases involving a sex chromosome abnormality were found to be of paternal origin while the two trisomic cases that could be analysed were of maternal origin. Two cases involved the same infertile couple who had two consecutive ICSI pregnancies terminated because of a chromosome abnormality. The replaced embryos in both cases originated from a single batch of ICSI fertilized oocytes of which part was used to initiate the first pregnancy and part was cryopreserved and used to initiate the second pregnancy.

Chromosome Aberrations↗
PubMed1997

Two cases of Robertsonian translocations in oligozoospermic males and their consequences for pregnancies induced by intracytoplasmic sperm injection.

Two case histories are presented documenting structural chromosome abnormalities in infertile males. The abnormalities were detected only after application of intracytoplasmic sperm injection (ICSI) was repeatedly unsuccessful or resulted in an abnormal pregnancy. A mosaic Robertsonian translocation 45,XY,der(13;13)(q10; q10)/46,XY,t(13;13)(p10;p10), der(13p;13p) incompatible with normal offspring was found in a male with extreme oligozoospermia after three subsequent ICSI treatments were unsuccessful and one had resulted in a spontaneous abortion. A second case involved a Robertsonian translocation 45,XY,der(13;14)(q10;q10) which was detected in a male with extreme oligozoospermia after ultrasound abnormalities were found in an ICSI-induced twin pregnancy. Amniocentesis showed an unbalanced 46,XY,+13,der(13;14)(q10;q10) karyotype in one twin and a Robertsonian 45,XX,der(13;14)(q10;q10) karyotype in the other twin. Chromosome analysis of males with abnormal sperm characteristics is advised prior to ICSI.

Adult↗
PubMed1996

Ring chromosome 18 in a fetus with only facial anomalies.

We report on a prenatally detected case of ring chromosome 18 [46,XX,r(18)] in amniotic fluid cells of a fetus with an abnormal facial profile on ultrasound as the only malformation. The chromosome 18 origin of the ring chromosome, of a supernumerary marker chromosome in some cells, and of micronuclei was demonstrated by fluorescent in situ hybridization with a whole chromosome 18 paint (Cambio) and 18 centromere probe L1.84. DNA investigations showed deletions of 18p as well as 18q material of r(18), which turned out to be of paternal origin. Autopsy of the fetus after termination of pregnancy at 20 weeks of gestation showed no additional malformations, in agreement with the previous ultrasound findings.

Abortion, Induced↗
PubMed1996

A case of early intrauterine parvovirus B19 infection.

We present a case of parvovirus B19 infection in the first trimester, confirmed by polymerase chain reaction (PCR) in amniotic fluid and cord blood, that caused myocarditis, severe intrauterine growth retardation, and probably glomerulonephritis. Eventually a small-for-dates neonate was born, without any signs of the infection.

Adult↗
PubMed1996

Chorionic villus sampling and materno-fetal transfusions: an immunological pathogenesis of vascular disruptive syndromes?

Experimental materno-embryonic transfusions with serum that is immunologically active against blood group antigens cause congenital malformations in the rat embryo. In view of the possible increased incidence of vascular disruptive syndromes after chorionic villus sampling (CVS), we investigated the occurrence of materno-fetal transfusions (MFTs) in this procedure. In 18 pregnant women experiencing two needle introductions at CVS, we looked immunohistochemically at the presence of haemoglobin A1-containing maternal erythrocytes in the fetal circulation of the separately collected first and second chorionic villus samples. In 4 of 18 patients (22 per cent), a significant increase of maternal cells was observed in the second sample compared with the first sample, indicating the occurrence of MFT by CVS. On the rare occasion of maternal immunization against fetal antigens, a CVS-associated MFT might provoke immunological damage to the fetus.

Antigen-Antibody Reactions↗
PubMed1996

Prenatal diagnosis of fetal abdominal wall defects: a retrospective analysis of 44 cases.

Forty-four fetal abdominal wall defects, consisting of 31 omphalocoeles, 11 cases of gastroschisis, and two body stalk anomalies (which are excluded from further analysis), were diagnosed at 12-39 weeks (median 26 weeks) of gestation. In 10/31 (32 per cent) cases of omphalocoele and in 4/11 (36 per cent) cases of gastroschisis, multiple congenital anomalies were diagnosed. A normal amount of amniotic fluid was present in 39 cases; in three cases of omphalocoele an abnormal amount of amniotic fluid (polyhydramnios, n = 2; oligohydramnios, n = 1) was seen. Prenatally, intrauterine growth retardation (IUGR) was diagnosed in each type of anomaly only once, although the birth weight was below the tenth centile in 23 per cent of omphalocoeles and in 36 per cent of cases of gastroschisis. An abnormal prenatal karyotpye was established in 5/25 (20 per cent) cases of omphalocoele versus none in the gastroschisis group. In 36 cases an expectant obstetric management was followed, and in six cases of omphalocoele the pregnancies were terminated because of severe multiple anomalies (n = 3) or an abnormal prenatal karyotype (n = 3). The preterm delivery rate (excluding terminations) was 12/25 (48 per cent) in the omphalocoele subgroup versus 8/11 (73 per cent) in the gastroschisis subgroup. The Caesarean section rate was almost identical (19 versus 18 per cent) in both subgroups; the majority (n = 5) were performed to protect the abdominal wall defect. The overall survival rate was 39 per cent in the omphalocoele group; in all surviving infants this was the sole congenital anomaly and in each instance there was a normal karyotype. In the gastroschisis group, 8/11 (72 per cent) infants survived, of which two children also displayed unilateral hydronephrosis.

Abdominal Muscles↗
PubMed1996

Fetal outcome in nuchal translucency with emphasis on normal fetal karyotype.

The aim of this study was to evaluate fetal outcome in fetuses with a nuchal translucency thickness of 3 mm or more, with emphasis on those with a normal karyotype. Between 1991 and 1994, a total of 104 pregnancies with suspected ultrasound abnormalities were referred to our prenatal unit for a fetal anomaly scan before 16 weeks of gestation. Of these 104 pregnancies, 54 were referred because of a nuchal translucency thickness of 3 mm or more. Data on these 54 pregnancies will be presented. Karyotyping was performed in all cases. An abnormal karyotype was found in 26/54 (48 per cent) pregnancies. A normal karyotype was established in the remaining 28 pregnancies. In this subset, five associated structural anomalies were detected at the first anomaly scan (9-15 weeks). Two pregnancies were terminated because of isolated nuchal translucency. In four of the continuing 21 pregnancies, additional structural anomalies were detected only at the second anomaly scan (16-20 weeks). Two of these were terminated because of bilateral renal dysplasia and a combination of exomphalos and ectopia cordis. Finally, 19 pregnancies progressed uneventfully and resulted in spontaneous delivery at a median gestational age of 40 weeks. A statistically significant difference in mean nuchal translucency thickness was found between cases with and without associated structural anomalies. This relationship indicates a more pronounced nuchal translucency thickness to be associated with a higher incidence of additional structural anomalies and, as a result, a poorer fetal outcome.

Chromosome Aberrations↗
PubMed1996

Clinical significance of placenta-confined nonmosaic trisomy 16.

Since the introduction of chorionic villi sampling in 1984 we have observed five first-trimester cases of nonmosaic placenta confined trisomy 16. At subsequent follow-up it appeared that all five had an adverse maternal or fetal outcome. In three cases the mother had preeclampsia. Two of the infants were born with multiple congenital abnormalities, including tetralogy of Fallot. All children were growth retarded.

Abnormalities, Multiple↗