title: First trimester biochemistry at different maternal ages.
abstract: BACKGROUND
  The performance of first trimester biochemical screening was compared at different pregnancy weeks and maternal ages during 2002-2008 in a screened population of 76,949 women.
  
  
  METHODS
  The detection rates, as well as the median multiples of a median (MOMs) of free β-human chorionic gonadotropin (free β-hCG) and pregnancy-associated plasma protein-A (PAPP-A), were compared between completed gestational weeks 8-13 and between different maternal ages separated into 5-year groupings.
  
  
  RESULTS
  The number of singleton Down syndrome pregnancies was 221. The median age of the screened women was 30 years and the proportion of women aged ≥ 35 years 16.9%. The median age of the women with a Down syndrome pregnancy was 37 years. In women aged <35 years, the biochemical markers provided a detection rate of only 38.6%, whereas in women aged ≥ 35 years, the biochemical markers detected 82.7% of cases (p<0.01).
  
  
  CONCLUSIONS
  Biochemical screening works best amongst women aged ≥ 35 years. For younger mothers aged <35 years, combined screening should be the method of choice.
authors: Department of Clinical Chemistry, School of Medicine, Faculty of Health Sciences, University of Eastern Finland, Kuopio, Finland.
authors: Jenni K
authors: JK
authors: Ranta
authors: Jaana
authors: J
authors: Marttala
authors: Päivi
authors: P
authors: Laitinen
authors: Johanna
authors: J
authors: Kultti
authors: Olavi
authors: O
authors: Kauhanen
authors: Jarkko
authors: J
authors: Romppanen
authors: Esa
authors: E
authors: Hämäläinen
authors: Seppo
authors: S
authors: Heinonen
authors: Kari
authors: K
authors: Pulkki
authors: Markku
authors: M
authors: Ryynänen
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000378:metabolism; D005260:Female; D005865:Gestational Age; D006801:Humans; D008423:Maternal Age; D008875:Middle Aged; D011247:Pregnancy; D011261:Pregnancy Trimester, First / Q000378:metabolism* / Q000502:physiology; D011266:Pregnancy-Associated Plasma Protein-A / Q000378:metabolism; D055815:Young Adult
chemical_list: D015415:Biomarkers; D018997:Chorionic Gonadotropin, beta Subunit, Human; D011266:Pregnancy-Associated Plasma Protein-A