Why might maternal serum AFP be high in pregnancies in which the fetus is normally formed?

This publication has 16 references indexed in Scilit:

• The effect of smoking in pregnancy on maternal serum alpha‐fetoprotein, unconjugated oestriol, human chorionic gonadotrophin, progesterone and dehydroepiandrosterone sulphate levels
  BJOG: An International Journal of Obstetrics and Gynaecology, 1990
• Predictive values, relative risks, and overall benefits of high and low maternal serum α-fetoprotein screening in singleton pregnancies: New epidemiologic data
  American Journal of Obstetrics and Gynecology, 1989
• Placental pathology at term associated with elevated midtrimester maternal serum α-fetoprotein concentration
  American Journal of Obstetrics and Gynecology, 1988
• Feto-maternal transfusion after chorionic villus sampling
  Human Genetics, 1988
• Quantitative structure of the normal human placenta from 10 weeks of gestation to term
  Early Human Development, 1984
• Second-trimester placental changes associated with elevated maternal serum α-fetoprotein
  American Journal of Obstetrics and Gynecology, 1982
• THE RELATION BETWEEN MATERNAL SERUM ALPHA‐FETOPROTEIN LEVELS AND FETOMATERNAL HAEMORRHAGE
  BJOG: An International Journal of Obstetrics and Gynaecology, 1979
• SIGNIFICANCE OF ELEVATED MID-TRIMESTER MATERNAL PLASMA-ALPHA-FETOPROTEIN VALUES
  The Lancet, 1979
• MATERNAL SERUM-ALPHA-FETOPROTEIN MEASUREMENTS AS AN EARLY INDICATOR OF LOW BIRTH-WEIGHT
  The Lancet, 1977
• MATERNAL PLASMA ALPHA‐FETOPROTEIN IN NORMAL AND COMPLICATED PREGNANCIES
  BJOG: An International Journal of Obstetrics and Gynaecology, 1976