2ND-TRIMESTER MATERNAL SERUM IMMUNOREACTIVE INHIBIN AS A MARKER FOR FETAL DOWNS-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

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 pattern 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

How women deal with the results of serum screening for Down syndrome in the second trimester of pregnancy

To gain insight into how pregnant women experience serum screening for Down syndrome, we sent questionnaires to two groups of relevant subjects in the north of the Netherlands. The questionnaires addressed the following issues: decision-making process, knowledge and opinions. Questionnaire A was sent to women of 36 years of age and older (n = 99) (group A) who were all 20 to 36 weeks pregnant at that time. In the Netherlands prenatal diagnosis is routinely available to these women. Questionnaire B was sent to women of younger than 36 years (n = 69) (group B) who had received a screen-positive result and had subsequently undergone amniocentesis. About half of these women were still pregnant at that time. For these women, serum screening is only available on the basis of opting-in. The two questionnaires were largely identical. The response rates to questionnaires A and B were 82% and 91%, respectively. Group A (women of 36 years and older) considered that second trimester serum screening made a welcome contribution to the decision-making process about whether to undergo amniocentesis. Moreover, it reduced the amniocentesis rate considerably. The vast majority said they would apply for serum screening in a following pregnancy, but favoured the idea of first trimester screening. In group B (women of younger than 36 years), reassurance was the most commonly mentioned reason for undergoing serum screening. Almost all the women experienced some degree of anxiety when they were informed about the screen-positive result and 13% continued to be anxious, even after the favourable result of the amniocentesis. The majority of the respondents would also apply for serum screening in a following pregnancy and were of the opinion that this screening should be offered to all pregnant women in the Netherlands. Copyright (C) 2000 John Wiley & Sons, Ltd