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J M Van Lith

Publications and source records attributed to J M Van Lith.

16 recordsLinked to original sources
PubMed1998

First trimester maternal serum concentrations of fetal antigen 2 in normal pregnancies and those affected by trisomy 21.

Serum concentrations of fetal antigen 2 (FA-2), the amino-propeptide of the alpha1 chain of collagen type I, were measured in peripheral blood from women with normal (n = 234) and trisomy 21 affected (n = 14) pregnancies between 9 and 11 weeks gestation. Serum FA-2 concentrations were seen to be stable throughout this period, and though raised FA-2 concentrations were seen at the 10th week of gestation, a statistically significant difference between normal and trisomy 21 affected pregnancies was not found overall. Therefore it seems unlikely that FA-2 has a role in first trimester screening for trisomy 21, despite the fact that significantly higher FA-2 concentrations in trisomy 21 and significantly lower concentrations in trisomy 18 had been previously demonstrated in amniotic fluid in the second trimester.

Biological Assay↗
PubMed1995

Nuchal translucency measurement in normal fetuses.

OBJECTIVE: To construct a normal range for the nuchal translucency measurement in chromosomally and phenotypically normal fetuses between 9 and 14 weeks' gestation. METHODS: The nuchal translucency was measured prospectively in 771 chromosomally normal fetuses of women attending our antenatal clinic or prenatal diagnosis center. The nuchal translucency measurement was expressed as the median and fifth, 25th, 75th, and 95th percentiles according to completed weeks of gestation based on ultrasound measurements. RESULTS: The median nuchal translucency measurement increased from 0.7 mm at 10 weeks' gestation to 1.5 mm at 13 weeks. A nuchal translucency measurement greater than 2.5 mm was found in 4.6% of the fetuses at 10 weeks' gestation; the incidence increased to 8.7% at 14 weeks. CONCLUSION: In normal fetuses, there is a physiologic variation in the nuchal translucency measurement between 9 and 14 weeks' gestation. The calculation of risk for trisomies based on this measurement should take this variation into account. The adoption of a gestational age-dependent cutoff point, based on the deviation of a given measurement from the median, may reduce the number of false-positive test results requiring invasive procedures for karyotyping.

Adolescent↗
PubMed1994

First-trimester maternal serum alpha-fetoprotein as a marker for fetal chromosomal disorders. Dutch Working Party on Prenatal Diagnosis.

We evaluated first-trimester maternal serum alpha-fetoprotein (MS-AFP) as a marker for fetal chromosomal disorders. The multicentre study was performed under the auspices of the Dutch Working Party on Prenatal Diagnosis. MS-AFP was measured in 2404 normal pregnancies and 72 chromosomally abnormal pregnancies. The median multiple of the normal median (MOM) in 32 Down's syndrome pregnancies was 0.83 with a 95 per cent confidence interval ranging from 0.60 to 1.04. The difference between the distributions of first-trimester MS-AFP in normal and Down's syndrome pregnancies was statistically significant (t-test: t = 2.34, P < 0.05). Thirty-one per cent of the Down's syndrome pregnancies were found below the tenth percentile. We found no difference between normal pregnancies and pregnancies with other chromosomal disorders (eight cases with trisomy 18, MOM = 1.26; seven cases with sex chromosome abnormalities, MOM = 1.07; 22 cases with a chromosomal mosaic pattern in chorionic villi, MOM = 1.08). We conclude that first-trimester MS-AFP can discriminate between normal and Down's syndrome pregnancies, but is not an effective marker. First-trimester MS-AFP has no value as a marker for other fetal chromosomal disorders.

Chromosome Aberrations↗
PubMed1994

First-trimester maternal serum immunoreactive inhibin in chromosomally normal and abnormal pregnancies. Dutch Working Party on Prenatal Diagnosis.

OBJECTIVE: To investigate the maternal serum immunoreactive inhibin level in chromosomally normal and abnormal pregnancies in the first trimester. METHODS: This was a retrospective study under the auspices of the Dutch Working Party on Prenatal Diagnosis. Maternal serum samples were taken before prenatal diagnosis. Forty-eight maternal serum samples from chromosomally abnormal pregnancies, including 23 with Down syndrome, were available for analysis; 284 samples from chromosomally normal pregnancies were used to establish reference ranges. RESULTS: The median value of maternal serum immunoreactive inhibin in the 23 Down syndrome pregnancies was 1.3 multiples of the normal median (95% confidence interval 0.8-2.1). No significant difference was found between the distributions of the inhibin concentrations in the normal and the Down syndrome pregnancies or in the normal and the other chromosomally abnormal pregnancies. CONCLUSION: In contrast to the second trimester of pregnancy, the level of maternal serum immunoreactive inhibin in the first trimester is not related to fetal chromosomal abnormalities and therefore is not useful as a biochemical screening index.

Adult↗
PubMed1993

Maternal serum CA 125 levels in pregnancies with chromosomally-normal and -abnormal fetuses. Dutch Working Party on Prenatal Diagnosis.

We measured the maternal serum cancer antigen 125 (MS-CA 125) levels in 98 nonpregnant women, 765 first- and second-trimester pregnancies with chromosomally-normal fetuses, and 54 chromosomally-abnormal pregnancies. To determine the MS-CA 125 concentration, we used a new automated microparticle enzyme immunoassay with low inter-assay variability. The median MS-CA 125 level decreased from the first to the second trimester of pregnancy and was higher than that in non-pregnant women. We found no difference between normal and Down's syndrome (n = 29) pregnancies (t-test: t = 0.57, p > 0.5). The MS-CA 125 levels in pregnancies with other chromosomal abnormalities showed no difference either, compared with the normals. We conclude that MS-CA 125 is not a useful marker for fetal Down's syndrome, nor for other chromosomal disorders in pregnancy.

Abortion, Spontaneous↗
PubMed1992

First-trimester maternal serum human chorionic gonadotrophin as a marker for fetal chromosomal disorders. The Dutch Working Party on Prenatal Diagnosis.

The Dutch Working Party on Prenatal Diagnosis has initiated a study on the possibilities of first-trimester screening for fetal chromosomal disorders. We report on maternal serum human chorionic gonadotrophin (MS-hCG) measurements in 1348 pregnancies with a chromosomally normal fetus and 53 pregnancies with a chromosomally abnormal fetus. The median MS-hCG concentration in 24 pregnancies with Down's syndrome was 1.19 multiples of the normal median (MoM). The MS-hCG distributions in normal and Down's syndrome pregnancies did not differ significantly (t-test: t = 1.945, p greater than 0.05). We also found no difference between normal pregnancies and pregnancies with other chromosomal disorders (six cases of trisomy 18, MoM = 0.80; four cases of sex chromosome abnormality, MoM = 1.01; 17 cases of chromosomal mosaicism in chorionic villi, MoM = 1.11). Selecting an upper limit at the 90th centile could detect 25 per cent of pregnancies with Down's syndrome. We conclude that, in the first trimester, MS-hCG as a screening factor for Down's syndrome is of minor value. However, MS-hCG could be a useful factor in a first-trimester screening programme based on a combination of markers.

Chorionic Gonadotropin↗
PubMed1992

Increased maternal serum alpha-fetoprotein and human chorionic gonadotropin in compromised pregnancies other than for neural tube defects or Down syndrome.

Intrauterine fetal death occurred in four women who were 'screen-positive' in a screening programme for neural tube defects (NTDs) and Down syndrome (DS). These women had very high levels of maternal serum alpha-fetoprotein (MSAFP) and maternal serum human chorionic gonadotropin (MShCG). Therefore, we evaluated all 'screen-positive' women in whom both of these markers were greater than or equal to 2.0 multiples of the median. The cases fulfilling these criteria totalled 11, and only one of them had no complications. High concentrations of both MSAFP and MShCG in a number of these cases might have been caused by an increased placental volume, which, in turn, might have been induced by decreased perfusion of the placenta. We conclude that screening programmes wrongly determine a high risk of fetal NTD or DS if the concentrations of both these parameters are very high. Invasive diagnostic procedures should be avoided in these cases, particularly in view of the increased risk of an adverse pregnancy outcome.

Adult↗
PubMed1992

Second-trimester maternal serum immunoreactive inhibin as a marker for fetal Down's syndrome.

We measured immunoreactive inhibin in the maternal serum of 80 pregnancies with a chromosomally normal fetus and ten Down's syndrome pregnancies in the second trimester. The inhibin level in all Down's syndrome pregnancies was above the normal median; the multiple of the normal median (MoM) was 1.9. We found a statistically significant difference between the levels of inhibin in unaffected and affected pregnancies (Kolmogorov-Smirnov test: p < 0.002). Using an arbitrarily chosen cut-off of 2.4 MoM, 40 per cent of Down's syndrome and 5 per cent of the normal pregnancies were found. We conclude that immunoreactive inhibin may be useful as a marker for fetal Down's syndrome.

Biomarkers↗
PubMed1992

Fetal heart rate in early pregnancy and chromosomal disorders.

OBJECTIVE: To investigate normal fetal heart rate in early pregnancy and assess the hypothesis that abnormal fetal heart rate is associated with fetal chromosomal abnormalities. DESIGN: Prospective descriptive cross-sectional study. SETTING: Antenatal clinic associated to the University Clinic of Obstetrics, University Hospital Groningen, The Netherlands. SUBJECTS: 424 pregnant women who attended for prenatal counselling. INTERVENTIONS: Measurements of fetal heart rate from 6-16 weeks gestation, cross-sectional study. MAIN OUTCOME MEASURES: Fetal heart rate expressed as beats/min. RESULTS: Karyotyping showed a normal chromosomal pattern in 414 fetuses. The median fetal heart rate increased from 138 beats/min at 6 weeks to 177 beats/min at 9 weeks, thereafter, fetal heart rate gradually decreased to 150 beats/min at 16 weeks. Karyotyping showed 10 abnormalities: five trisomies 21, three trisomies 18, and two mosaic patterns in chorionic villi. Fetal heart rate of the trisomic fetuses was distributed around the median with that of all Down's syndrome fetuses within the normal range. In one fetus with trisomy 18, the heart rate exceeded the 90th centile, in another it fell under the 10th centile. The two fetuses with a mosaic pattern in chorionic villi had heart rates outside the normal range. CONCLUSION: Fetal heart rate in chromosomally abnormal fetuses in early pregnancy do not appear to be consistently different from that in normal fetuses. The use of a single measurement of fetal heart rate is not valuable for screening purposes. Chromosomal mosaicism in chorionic villi may be associated with abnormal fetal heart rate.

Chromosome Aberrations↗
PubMed1992

Second trimester amniocentesis in twin pregnancies: maternal haemoglobin as a dye marker to differentiate diamniotic twins.

OBJECTIVE: To review the use of a membrane-free haemolysate prepared from maternal blood to distinguish the amniotic sacs at amniocentesis in twin gestation. SETTING: University Hospital, Groningen. METHOD: Haemoglobin solution prepared from maternal blood. SUBJECTS: 63 twin pregnancies having amniocentesis. RESULTS: The fetal loss before 28 weeks was 4%. There was no perinatal mortality. Dye was detected in the second sac in 9 of 24 women tested before 1985 and none of the 39 women since, no malformations could be ascribed to the use of the haemolysate. CONCLUSION: The use of the membrane-free haemolysate is safe, but the technique will probably gradually become redundant because of improved ultrasound.

Amniocentesis↗
PubMed1991

Follow-up and pregnancy outcome after a diagnosis of mosaicism in CVS.

In 2103 consecutive diagnostic chorionic villus samples, examined in a 4-year period in our clinical genetics unit, 26 samples (1.2 per cent) presented chromosomal mosaicism in the direct and/or long-term culture preparations. Only once (46,XX/47,XX,+9) was the mosaicism confirmed in the fetus. In the cytogenetic follow-up studies of the remaining 25 pregnancies, in no cases could the aberration be confirmed in amniotic fluid or fetal tissue. One patient requested a termination after the CVS result. Of the remaining 24 pregnancies, four (16.7 per cent) ended in a spontaneous abortion. These findings suggest an association between placental mosaicism and fetal loss.

Abortion, Spontaneous↗
PubMed1991

First-trimester screening for fetal chromosomal abnormalities. Preliminary results. Dutch Working Party on Prenatal Diagnosis.

We have started a multicentre trial to study the possibilities of first-trimester maternal serum screening for fetal chromosomal abnormalities. Maternal blood samples were obtained before 13 weeks of gestation. We present the preliminary results of the first 950 patients on alpha-fetoprotein (AFP). Results on cancer antigen 125 (CA 125) in Down's syndrome and normal pregnancies are also presented. We conclude that the results on AFP are promising and that CA 125 might be predictive for fetal Down's syndrome.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1991

Alpha-fetoprotein in fetal serum, amniotic fluid, and maternal serum.

In order to gain more insight into the association between alpha-fetoprotein (AFP) and fetal chromosomal disorders, especially Down's syndrome, we measured AFP in fetal serum, amniotic fluid, and maternal serum at cordocentesis. We compared the concentration and gradient of AFP in these three compartments. Our data confirm earlier findings on second-trimester fetal serum AFP concentration. The results indicate that low maternal serum AFP in pregnancies with fetal chromosomal disorders could result from an impaired fetal kidney function as well as from impaired membrane or placental passage of AFP, rather than from reduced fetal AFP production.

Amniotic Fluid↗