title: First-trimester maternal serum Schwangerschafts protein 1 (SP1) in pregnancies associated with chromosomal anomalies.
abstract: The relationship between first-trimester maternal serum Schwangerschafts protein 1 (SP1) and the karyotype of the pregnancy was examined in 692 women who underwent chorionic villus biopsy at 6-12 weeks. There were 30 pregnancies with abnormal karyotypes, consisting of 14 Down's syndrome (DS), eight trisomy 18, and eight other anomalies, two of which were mosaics. The normal ranges and medians for gestation were defined from the 662 cases in which the karyotype was normal. The median SP1 (0.5 MOM) of the abnormal group was significantly lower than that of the normal group (1.0 MOM). This relationship was maintained for the DS pregnancies (0.4 MOM) and for anomalies other than trisomy 18 (0.43 MOM) but not trisomy 18 (1.1 MOM). It is possible that the use of SP1 as a screening test for chromosome anomalies in the first trimester could have a 43 per cent detection rate for a 5 per cent false-positive rate.
authors.affiliation: Joint Academic Unit of Obstetrics, Gynaecology and Reproductive Physiology, St Bartholomews Hospital Medical College, London, U.K.
authors.forename: M C
authors.initials: MC
authors.lastname: MacIntosh
authors.forename: B
authors.initials: B
authors.lastname: Brambati
authors.forename: T
authors.initials: T
authors.lastname: Chard
authors.forename: J G
authors.initials: JG
authors.lastname: Grudzinskas
mesh_terms: D000328:Adult; D015193:Chorionic Villi Sampling; D002869:Chromosome Aberrations / Q000097:blood*; D025063:Chromosome Disorders; D005260:Female; D006801:Humans; D007621:Karyotyping; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000097:blood*; D011261:Pregnancy Trimester, First
chemical_list: D011257:Pregnancy Proteins