title: Alpha-fetoprotein and its value for predicting pregnancy outcomes - a re-evaluation.
abstract: BACKGROUND
  Alpha-fetoprotein (AFP) concentrations can be determined framing others from invasively acquired amnion fluid (AF-AFP). While the biological role of AFP remains unclear it is well known that AFP-levels can be altered in connection with specific clinical and/or genetic alterations of the fetus.
  
  
  METHODS
  here a retrospective study based on 3,119 singleton and 56 twin pregnancies is presented. The standard levels of amnion fluid derived alpha-fetoprotein level (AF-AFP) between 12th and 36th weeks of gestation were determined. Additionally, acetylcholinesterase (AChE) test results for 63 cases, ultrasonography results for 32 cases and abnormal karyotypic findings for 100 cases were available for selected cases.
  
  
  CONCLUSIONS
  according to the present data the AF-AFP test is reliable and provides expected test results in terms of population studies. However, individual AF-AFP test results can be subject to high individual variations. In this study AF-AFP multiple of medians (MoM) over 1.7 were indicative for neuronal tube defects and/or omphalocele in only 6.3% of the cases, while such AF-AFP values were hints on severe sonographic signs in 62% of the cases. Also, altered AF-AFP concentrations were present in 82% of cytogenetically abnormal cases. Overall, even though predicative value of the AF-AFP-test is matter of discussion it continues to be widely applied in invasive prenatal diagnostics. This study indicates that it only can be applied reliably in combination with other tests like banding cytogenetics, ultrasonography and all embedded in well-established genetic counseling.
authors.affiliation: Jena University Hospital, Friedrich Schiller University, Institute of Human Genetics, Jena, Germany.
authors.forename: Ayham Alhaj
authors.initials: AA
authors.lastname: Darouich
authors.affiliation: Jena University Hospital, Friedrich Schiller University, Institute of Human Genetics, Jena, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Liehr
authors.affiliation: Jena University Hospital, Friedrich Schiller University, Institute of Human Genetics, Jena, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Weise
authors.affiliation: Jena University Hospital, Friedrich Schiller University, Placenta-Labor, Department of Obstetrics, Jena, Germany.
authors.forename: Dietmar
authors.initials: D
authors.lastname: Schlembach
authors.affiliation: Jena University Hospital, Friedrich Schiller University, Placenta-Labor, Department of Obstetrics, Jena, Germany.
authors.forename: Ekkehart
authors.initials: E
authors.lastname: Schleußner
authors.affiliation: Jena University Hospital, Friedrich Schiller University, Institute of Clinical Chemistry and Laboratory Diagnostics, Jena, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Kiehntopf
authors.affiliation: Jena University Hospital, Friedrich Schiller University, Institute of Human Genetics, Jena, Germany; Jena University Hospital, Zentrum für ambulante Medizin, Jena, Germany.
authors.forename: Isolde
authors.initials: I
authors.lastname: Schreyer
keywords: acetylcholinesterase (AChE); amnion fluid derived alpha-fetoprotein level (AF-AFP); chromosomal aberrations; ultrasonography