Prenatal diagnosis in the form of cytogenetic analysis of cultured fetal cells was introduced in the early 1970's in the Nordic countries. The total number of analyses carried out in 1970-1990 was approximately 70,000 in Denmark, which has the largest number of investigations, and approximately 7,500 in Norway having the lowest rate per 1,000 live births. Since the 1970's there has been access to induced abortions in all the Nordic countries. Table III shows the total number of analyses during 1988-1990 as well as total number of prenatal investigations per 1,000 live births. Table IV presents the percentage of chorionic samples in relation to the total number of investigations and Table VI shows the number of induced abortions in pregnancies with prenatally diagnosed abnormal fetuses. An English version of the article can be obtained from the authors.
On account of an increase in the frequency of amniotic fluid samples (AFS), the need for further decentralisation of sampling developed. Viborg Amt (Viborg County) was able to offer this service to all pregnant women in the county after 01.VIII.1985 who fulfil the indication for prenatal diagnosis (PD). Among 902 registered AFS divided over a period of two years before and two years after the decentralisation there was no significant deterioration of the service measured by the number of spontaneous abortions and unsuccessful AFS. The indications for prenatal diagnosis altered in such a way that the unofficial indication of anxiety rose significantly while the indication of maternal age greater than or equal to 35 years decreased. Furthermore, a positive correlation was registered between a reduction of distance from the pregnant woman to the centre of sampling and the percentage of referrals made by the local practitioner. The paper also shows that more pregnant women, referred for AFS on account of advanced age, accepted PD than was registered in an earlier research, but this pattern declined in the research period.
Department of Pathology and Molecular Medicine, Faculty of Health Sciences, McMaster University Medical Centre, 1200 Main Street West, Hamilton, Ontario L8N 3Z5, Canada.
In 1989, the Province of Ontario established a molecular diagnostic laboratory for carrier detection and prenatal diagnosis of hemoglobinopathies. Over the past 15 years, the laboratory has provided prenatal diagnosis for 672 pregnancies at-risk for severe hemoglobinopathies: 276 (41%) for homozygous beta-thalassemia or hemoglobin (Hb) E/beta-thalassemia, 211 (31%) for homozygous alpha 0-thalassemia (Hb Bart's hydrops fetalis), and/or Hb H disease, and 185 (28%) for various sickling disorders (Hb SS, Hb SC, Hb S/beta-thalassemia). Despite the availability of services for carrier screening, genetic counseling, and prenatal diagnosis, there has been only a modest reduction in the overall incidence of hemoglobinopathies in Ontario.
The results of investigation of 908 chorion and placental biopsy in 873 pregnant women of high risk a group is presented. Fetal pathology was diagnosed with the help of "direct" method and shot-term method of culture of chorionic villi and placenta, as well as method of long-term fetal lymphocyte cultures. The efficiency of invasive methods of prenatal diagnosis, and their role in decrease of perinatal disease and mortality was confirmed.
Department of Fetal Medicine, Copenhagen University Hospital Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark. caroline_winther@hotmail.com
This study investigated the gender distribution in karyotype results from chorionic villus samples and amniocenteses performed due to an increased risk for Down syndrome based on first-trimester combined risk assessment.
All prenatal karyotypes performed from 2006-2008 due to a risk assessment above 1:300 were retrieved from the Danish Central Cytogenetic Register. The distribution of gender for all newborns was obtained from Statistics Denmark. The ?(2) test and odds ratios were used for intergroup comparison.
We retrieved 5 157 karyotype results (54.9% male and 45.1% female karyotypes), of which 4 662 were normal. During the same period, 100 112 boys and 94 732 girls were born. Women carrying male fetuses were significantly more often referred for invasive testing than women carrying female fetuses (2.8 vs. 2.5%, p
