title: Biochemical tests of placental function for assessment in pregnancy.
abstract: BACKGROUND
  Biochemical tests of placental or feto-placental function were widely used in the 1960s and 1970s in high-risk pregnancies to try to predict, and thus try to avoid, adverse fetal outcome.
  
  
  OBJECTIVE
  To assess the effects of performing biochemical tests of placental function in high-risk, low-risk, or unselected pregnancies.
  
  
  METHODS
  Comprehensive electronic search of the Cochrane Pregnancy and Childbirth Group trials register (February 2003).
  
  
  METHODS
  Controlled trials (randomized or 'quasi-randomized') that compare the use of biochemical tests of placental function in pregnancy with non-use.
  
  
  METHODS
  Trial quality was assessed and data were extracted by the reviewer.
  
  
  RESULTS
  A single eligible trial of poor quality was identified. It involved 622 women with high-risk pregnancies who had had plasma (o)estriol estimations. Women were allocated to have their (o)estriol results revealed or concealed on the basis of hospital record number (with attendant risk of selection bias). There were no obvious differences in perinatal mortality (relative risk (RR) 0.88, 95% confidence interval (CI) 0.36 to 2.13) or planned delivery (RR 0.97, 95% CI 0.81 to 1.15) between the two groups.
  
  
  CONCLUSIONS
  The available trial data do not support the use of (o)estriol estimation in high-risk pregnancies. The single small trial available does not have the power to exclude a beneficial effect but this is probably of historical interest since biochemical testing has been superseded by biophysical testing in antepartum fetal assessment.
authors.affiliation: Department of Obstetrics and Gynaecology, University of Liverpool, Liverpool, UK, L69 3BX. jneilson@liverpool.ac.uk
authors.forename: J P
authors.initials: JP
authors.lastname: Neilson
mesh_terms: D005260:Female; D005315:Fetal Diseases / Q000175:diagnosis*; D006801:Humans; D010925:Placental Function Tests; D010926:Placental Hormones; D011247:Pregnancy; D018566:Pregnancy, High-Risk; D016032:Randomized Controlled Trials as Topic
chemical_list: D010926:Placental Hormones