OC042: Five years experience of screening for chromosomal anomalies in a 1st trimester OSCAR clinic
Year: 2003
Type: conference-abstract
Abstract: To evaluate the performance of a one-stop clinic for assessment of risk (OSCAR) for fetal anomalies by a combination of maternal age, fetal nuchal translucency (NT) thickness and maternal serum free beta-hCG and PAPP-A at 11 to 14 weeks of gestation in an NHS setting and in a private health care setting. Screening for trisomy 21 (T21) was carried by OSCAR in a private health care setting in 14 383 singleton pregnancies with live fetuses at 11–14 weeks and in an NHS hospital setting in 17 989 singleton pregnancies. The estimated risk for T21 was calculated and women with a risk of greater than 1 in 301 were counselled and the option of invasive testing discussed. Follow up of the outcome of all pregnancies was carried out. In the routine NHS setting uptake of first trimester screening was 97.5% of women offered screening. In this unselected population the median age was 30 years at time of screening, with 16% over 35. Of the women screened in the NHS setting 807 (4.5%) were identified At Increased Risk. Of these women 77% took up the offer of an invasive diagnostic test. In the self referred private clinic the median age was 34 with 47% over 35. Of the women screened in the private setting 1096 (7.6%) were identified At Increased Risk and all took up the offer of an invasive diagnostic test. The combined population contained 32 372 women of which 1903 (5.8%) were in the high risk group. In this group 127 pregnancies affected by T21 were observed for which screening identified 117 (92%). In addition screening identified 34 cases with T18, 15 with T13, 17 with Turner syndrome, 14 with triploidy and 10 with other chromosomal anomalies. Screening for T21 in the 1st trimester can be provided in a multidisciplinary OSCAR clinic and is associated with a prospective detection rate (over a 5 year period) of over 90% for a 5% false positive rate.
DOI: 10.1002/uog.256
Authors: K. Spencer, R. Bindra, K. Nicolaides
Institutions: Harold Wood Hospital, King's College Hospital
Language: English
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W2025870484